RCP8.5

There’s been a lengthy discussion on Twitter about RCP8.5. I think it was initiated by Roger Pielke Jr, who continues in his campaign to police the scientific community:

This complaint was then promoted by Matt Ridley, and the discussion ensued. It remained mostly quite pleasant, but I found it quite remarkable that people who have publicly discussed this topic for a good number of years, are still remarkably confused about something that is ultimately quite simple.

The criticism of RCP8.5 was a combination of it being completely unrealistic, and it being a scenario that climate scientists use in their studies so as to get more interesting results. In case some don’t know, RCP8.5 is one of the Representative Concentration Pathways (RCPs). These are a set of scenarios that consider different possible future atmospheric greenhouse gas (and aerosol) concentration pathways. They can also be regarded as possible future forcing pathways; pathways that produce a range of different externally-driven radiative perturbations. They go from one in which we keep the concentrations, and resulting change in forcing, quite low (RCP2.6) to one (RCP8.5) in which the concentrations keep rising, eventually reaching a level such that the change in forcing, by 2100, is 8.5 Wm-2.

These concentration (or forcing) pathways can then be used as input to climate models to try to understand how our climate will respond to a range of different possible future pathways. However, to relate these concentration pathways to our actions requires associating them with emission pathways. However, given uncertainties in the response of the natural carbon sinks, there isn’t a single emission pathway for a given concentration pathway. Even though it would now seem unlikely that we will follow an emission pathway typically associated with RCP8.5, uncertainties in carbon cycle feedbacks mean that we can’t rule out that an emission pathway typically associated with a lower RCP could lead to us following a concentration pathway close to RCP8.5. Therefore, I don’t think we can yet definitively rule out RCP8.5.

The other issue is climate scientists supposedly using RCP8.5 in order to get more interesting results (what Roger calls climate porn). It may well be that climate scientists use RCP8.5 more often than other concentration pathways. One reason for using RCP8.5 is that a pathway with a large change in forcing allows one to better distinguish between the signal (i.e., the response to the change in external forcing) and the noise (the natural variations). One can then probably still use this to estimate what would happen were the change in forcing to be lower [Edit: As Katharine Hayhoe pointed out, you can do this because a high forcing pathway will move through the levels of change associated with the lower forcing pathways]. Another reason will also be that understanding extreme outcomes can, in some cases, be somewhat more important than studying outcomes that we would probably expect to not be particularly extreme.

Of course, I do think that people should be very clear about what they’re doing. It does seem unlikely that will now follow an emission pathway that will lead to an RCP8.5-like concentration/forcing pathway. Therefore people should not present results of studies that use RCP8.5 as being somehow likely. However, this does not mean that there is no value in still considering this pathway. As already mentioned, using a pathway with a large change in forcing can help to distinguish between the forced response, and internal variability. Additionally, there is also a chance that the more we dismiss the possibility of following an RCP8.5-like pathway, the more likely it becomes that we might actually follow one.

H/T: Marcus N Hofer
Simpson-Generator.

Update:
As pointed out on Twitter (H/T Ambarish Karmalkar) many studies actually use RCP4.5 and RCP8.5. In fact, when I did a quick search, a lot of the results did use both RCP4.5 and RCP8.5. The figure on Roger’s tweet also seems to show this; the two most commonly used scenarios are RCP4.5 and RCP8.5 (with RCP8.5 appearing to be used slightly more often than RCP4.5).

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271 Responses to RCP8.5

  1. jsam says:

    Faux outrage is my very favourite form of outrage. Fortunately it is the default setting in the denialist and luckwarmer communities.

  2. very helpful basic review of the RCP’s. Thank you. Which RCP matches most closely to current real world temps, CO2 levels, etc?

    Thanks

    Mike

  3. TTauriStellarBody says:

    RCP 8.5 represents something close to the ideal of many climate contains. . It also represents the “if no action is taken” scenario thus very useful as an exemplar of why action is needed. I understand that the critiques are more motivated by a desire to stir than engage but still its not like 8.5 has no functional use and is an outlier.

  4. > I found it quite remarkable that people who have publicly discussed this topic for a good number of years, are still remarkably confused about something that is ultimately quite simple.

    What’s even more remarkable, AT, is that after all these years you still find it remarkable.

  5. Science is doing something new. It makes sense to start with a case with a good signal to noise ratio. If it turns out to be important you can always do the others later.

    People studying impacts are naturally aware of which scenario was used. What matters most on the long term is whether we get out act together.

    Let me repeat my tweet here:

  6. jsam,
    Indeed. What struck me is that if some understand this, but don’t think it is clear, they could put some effort into clarifying. Instead, they infer nefarious behaviour by climate scientists and play to their audience – the dismissives.

    small,
    The last I looked, we were tracking along close to RCP8.5. It may have dropped down a bit, given than concentrations didn’t rise for a couple of years, but they have started rising again.

    TTauri,
    Yes, I do think that many of those who criticise RCP8.5 then promote things that would lead to it being more likely that we’d then follow it.

    Willard,
    Yes, fair point.

  7. Good grief:

  8. Where did those numbers come from?

  9. ‘What’s the worst thing that could happen’ is a very good starting point to assess risk.

  10. > Where did those numbers come from?

    1. Go to teh Scholar:

    https://scholar.google.com

    2. Search for “RCP 8.5” etc.

    3. Make sure you omit the quotes to have VERY BIG NUMBERS.

    I get 24,5K hits for “RCP 8.5” (again, without the quotes) which looks a lot like what Junior got.

    When I search for “”RCP 8.5″” I get 9 060 results, so it would not surprise me if he made a very simple search.

  11. paulski0 says:

    As pointed out on Twitter (H/T Ambarish Karmalkar) many studies actually use RCP4.5 and RCP8.5.

    Yes, it mostly seems to be a matter of funding and time limitation. Modelling groups are given 4 scenarios to follow but some may not be able to submit for all of them, so they focus on 2 or 3. RCP4.5 and RCP8.5 were run on pretty much all CMIP5 models. This makes sense, with RCP4.5 being representative of a plausible mitigation scenario and RCP8.5 a non-mitigation scenario while also being far enough away from 4.5 to be more scientifically useful (than RCP6.0). Only a subset of models ran RCP2.6 and RCP6.0. As a consequence it’s often difficult to justify papers utilising those scenarios.

  12. Thanks for this post, and thanks for deputizing me.
    Really, over here at least, the raising of issues, engaging in discussion is just called “science,” but whatevs.
    Here is a great example of the transformation of RCP 8.5 into climate porn: https://www.economist.com/blogs/graphicdetail/2018/05/daily-chart-5

  13. paulski0 says:

    rogerpielkejr,

    The paper you’re referencing seems to be an example of what ATTP was suggesting. They use RCP8.5 entirely for its signal-to-noise benefit and report the results in relative terms i.e. % variability per degree and GDP against % variability. The results aren’t dependent on RCP8.5 at all except in the signal-to-noise capacity.

    Which brings me to wondering what your actual problem is? Is it any attempt to study and report on climate change impacts? Is there any way to study harmful climate change impacts which you wouldn’t call “climate porn”?

  14. FWIW, ClimateBall ™ is sexier and less sexist than “climate porn.”

    Here’s a ClimateBall example involving the lowest bound of disingenuousness:

    Almost every catastrophic prediction is based on climate models using the RCP 8.5 scenario (RCP = relative concentration pathway) and a far-too high climate sensitivity. RCP 8.5 is not even suitable for bad science fiction. Actual emissions are tracking closer to RCP 6.0. When a realistic transient climate response is applied to RCP 6.0 emissions, the warming tracks RCP 4.5… A scenario which stays below the “2° C limit,” possibly even below 1.5° C.

    https://wattsupwiththat.com/2017/09/25/is-climate-lukewarmism-legitimate/

    It’s hard not to see in that episode the “but CAGW” meme under the form a fancy graph based on a simple divide-and-conquer trick.

  15. Which brings me to wondering what your actual problem is?
    –> Not sure, too many headers?

    Is it any attempt to study and report on climate change impacts?
    –> Well, I’ve published dozens of papers on this topic and cited hundreds, so … no.

    Is there any way to study harmful climate change impacts which you wouldn’t call “climate porn”?
    Sure, don’t present a <1% scenario (says IPCC) as BAU. Seems easy, no?

  16. > don’t present a <1% scenario (says IPCC)

    If the IPCC could attribute a valid statistic to scenarios, they would make predictions, not scenarios.

    Also, there are historical reasons that made RCP 8.5 what it is:

    Let's hope Paul Williams isn't a climate pornograph.

  17. IPCC retired RCP 8.5 in 2017.
    Climate impacts researchers surely should by 2018.
    Credibility is enhanced by not over-egging the pudding.
    Seems obvious.

  18. Since every ClimateBall episode provides a good reason to cite the IPCC’s deliverables, here’s a relevant claim from the AR5:

    Global mean temperatures will continue to rise over the 21st century if greenhouse gas (GHG) emissions continue unabated. Under the assumptions of the concentration-driven RCPs, global mean surface temperatures for 2081–2100, relative to 1986–2005 will likely be in the 5 to 95% range of the CMIP5 models; 0.3°C to 1.7°C (RCP2.6), 1.1°C to 2.6°C (RCP4.5), 1.4°C to 3.1°C (RCP6.0), 2.6°C to 4.8°C (RCP8.5). Global temperatures averaged over the period 2081–2100 are projected to likely exceed 1.5°C above 1850-1900 for RCP4.5, RCP6.0 and RCP8.5 (high confidence), are likely to exceed 2°C above 1850-1900 for RCP6.0 and RCP8.5 (high confidence) and are more likely than not to exceed 2°C for RCP4.5 (medium confidence). Temperature change above 2°C under RCP2.6 is unlikely (medium confidence). Warming above 4°C by 2081–2100 is unlikely in all RCPs (high confidence) except for RCP8.5, where it is about as likely as not (medium confidence). {12.4.1, Tables 12.2, 12.3, Figures 12.5, 12.8}

    http://ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter12_FINAL.pdf

    Note how the probabilities are applied to the model runs, not as an estimation of the odds that a scenario occurs or not. The assumptions of the different pathways involve societal choices (e.g. population and economic development) that would be tough to more than guesstimate. A worse case scenario, a best case scenario, and some scenarios in between ought to be enough to get a fairly useful ballpark.

  19. Sure, we are in complete agreement on this: “A worse case scenario, a best case scenario, and some scenarios in between ought to be enough to get a fairly useful ballpark.”
    Indeed.
    Use of only a implausible worst case scenario, and nothing else = bad science.
    Thx for the exchange.

  20. > IPCC retired RCP 8.5 in 2017. Climate impacts researchers surely should by 2018.

    And yet we got an article in Bloomberg of a timeless Scholar search about terms without quotes.

    Obviously, “credibility is enhanced by not over-egging the pudding” looks like a one-way street here.

  21. > Use of only a implausible worst case scenario, and nothing else = bad science.

    Which is exactly what being a megaphone for the “but CAGW” meme may ever accomplish. Besides:

    I’m running out of irony meter.

    ***

    FWIW, the next Summary for Policymakers will be ready in September 2019.

    Meanwhile, I’m afraid RPC 8.5 is here to stay.

  22. Magma says:

    Like other scientists, I give great weight to opinions on the state and quality of climate science offered by political scientists and economists with axes to grind. And the bigger the axe, the better.

  23. Here’s a very big axe, Magma:

    [The Editor] has done a great job documenting how RCP 8.5 has been frequently invoked as a “business-as-usual” scenario.

    {See “Is our certain fate a coal-burning climate apocalypse? No!” describes the implausible assumptions of RCP8.5 — which makes it a good worst-case analysis. Also see this about the use of RCP8.5: “Manufacturing climate nightmares: misusing science to create horrific predictions.“}

    In fact, once you start looking, you’ll see RCP 8.5 everywhere in the climate impacts literature.

    https://wattsupwiththat.com/2017/11/21/roger-pielke-jr-describes-the-politics-of-unlikely-climate-scenarios/

    Which leads us to:

    The middle two scenarios seem likely, RCP4.5 and RCP6.0. Both would have ill effects on the world, adding to the stress from increase in pollution and population growth. Neither are Armageddon (combined with our other problems, RCP8.5 might be close to Armageddon).

    https://fabiusmaximus.com/2017/07/28/ipcc-rcp2-6-good-news-about-climate-change/

    The title of that piece leads to this theorem: I don’t always look at worse-case scenarios, but when I do I need to emphasize the best one. Not sure how the Editor got his distinction between 4.5 and 6.0 with 8.5 as “not Armageddon,” but here you go.

    The “but CAGW” meme is alive and kicking.

  24. Chubbs says:

    Per Makita’s page, recent GHG forcing trends are x-rated.

  25. Willard says:

    > recent GHG forcing trends are x-rated.

    Because, climate porn.

    God I hate that expression.

  26. Steven Mosher says:

    “Which brings me to wondering what your actual problem is? Is it any attempt to study and report on climate change impacts? Is there any way to study harmful climate change impacts which you wouldn’t call “climate porn”?

    yes there is a way. As noted before here there are number of changes expected to happen under a 2C warming scenario that look like state changes. I’d say focus your resources there.

    Heck can anyone list the damages that are associated with 2C warming? Beuller?

    the List of bad shit that will happen if unicorns fly out of our butts ( RCP 8.5) hits the press every day.

    How about a list of bad shit that happens if we hit 2C warming? Beuller? Beuller?

    Isnt that list the one we should all know by heart to fuel a drive to 1.5C?

    whats the list?

    go.

    Willard you first

  27. Vintage April 2018:

    The report on Global Warming of 1.5°C is one of three special reports that the IPCC, the leading body for assessing the science related to climate change, is releasing over the next two years.

    This week’s meeting in Gaborone marks the culmination of the expert and government review of the draft report whose full title is Global Warming of 1.5°C: an IPCC special report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty. The outline of the report and the full list of authors can be found on the IPCC website.

    http://ipcc.ch/news_and_events/pr_sr15_lam4.shtml

  28. From the Editor’s “but CAGW” post above:

    The RCP2.6 emission and concentration pathway is representative of the literature on mitigation scenarios aiming to limit the increase of global mean temperature to 2°C. These scenarios form the low end of the scenario literature in terms of emissions and radiative forcing. They often show negative emissions from energy use in the second half of the 21st century. The RCP2.6 scenario is shown to be technically feasible in the IMAGE integrated assessment modeling framework from a medium emission baseline scenario, assuming full participation of all countries. Cumulative emissions of greenhouse gases from 2010 to 2100 need to be reduced by 70% compared to a baseline scenario, requiring substantial changes in energy use and emissions of non-CO2 gases. These measures (specifically the use of bio-energy and reforestation measures) also have clear consequences for global land use. Based on the RCP2.6 scenario, recommendations for further research on low emission scenarios have been formulated. These include the response of the climate system to a radiative forcing peak, the ability of society to achieve the required emission reduction rates given political and social inertia and the possibilities to further reduce emissions of non-CO2 gases.

    https://link.springer.com/article/10.1007%2Fs10584-011-0152-3

    No walk in the park there.

  29. Eli Rabett says:

    Steve,

    RCPs (really and imagined) determine the rate at which the climate changes. The outcomes and what happens when we reach them are things like a 1.5 C global temperature change. These two things are coupled, but not completely so although it would be interesting to think about exactly how they are coupled. As a general rule, the slower the rate of change, the better, but you also have to throw climate sensitivity into the mix.

    Bett’s take
    http://rsta.royalsocietypublishing.org/content/376/2119/20160452

  30. Steven Mosher says:

    Eli and Rbbit.

    I’m point to something different. I’m pointing to top of mind.

    without looking, without google, list the top 10 damages from 2C warming?
    can you? I can’t. It’s not part of my vocab.

    And I’m arguing that this should be top of mind. That we should know that like we know
    the hockey stick has been supported by dozens of studies. That we should know that
    like we know that GCMs have a rough time with clouds. That we should know that like
    we know that Susan aint a polar bear expert. That we should know that like we know that
    arctic ice is disappearing.

    ATTP posted a graph once. This is so far off my radar screen that I cant even remember the thread.
    I’m suggesting it should be front and center. In focus. That’s all.

  31. Steven Mosher says:

    shit Eli and Willard

  32. Roger,

    Really, over here at least, the raising of issues, engaging in discussion is just called “science,” but whatevs.

    Indeed, over here too. However, over here we often avoid suggesting what some are doing is reducing the credibility of their discipline.

    While you’re here, can you briefly explain the relevance of the Kaya identity and your Iron Law?

  33. Roger,

    Use of only a implausible worst case scenario, and nothing else = bad science.
    Thx for the exchange.

    Except it isn’t “nothing else” but the worst case scenario, and there are arguments (that people have pointed out to you) as to why one might use this scenario even if one doesn’t necessarily expect the worst case to materialise (signal-to-noise, and it passes through levels of change associated with other scenarios). So, you can claim that this is “bad science” if you wish. People don’t have to agree with you.

  34. Steven,

    ATTP posted a graph once. This is so far off my radar screen that I cant even remember the thread.

    This one, maybe?

  35. EFS,
    Thanks, I wanted to follow up on that. I see that that carbon brief article has an update on the figure that I showed earlier with actual emissions compared to emission pathways. Looks like we have dropped slightly below the emission pathways associated with RCP8.5 (or are at the low end of the range of possible emission pathways).

  36. verytallguy says:

    It’s instructive that
    (1) the SSP nearest to a reasonable definition of BAU corresponds to RCP7; less than 20% below RCP8.5
    (2) BECCS is significant across most of these. A near-magical technology never demonstrated at significant scale and with hugely destructive implications for land use.

    “IPCC have ditched RCP8.5” is a rather bizarre takehome AFAIKS.

  37. paulski0 says:

    rogerpielkejr

    Sure, don’t present a <1% scenario (says IPCC) as BAU. Seems easy, no?

    RCP8.5 is a BaU scenario by any reasonable definition, so that doesn’t make sense. Your <1% probability statistic is made up, and certainly doesn't come from the IPCC.

    The paper you've just referenced does not refer to RCP8.5 as BaU anywhere, so yeah that was easy. But wait, you've still called it "climate porn". So the question again is: Why?

  38. paulski0 says:

    Steven Mosher,

    yes there is a way. As noted before here there are number of changes expected to happen under a 2C warming scenario that look like state changes. I’d say focus your resources there.

    You’re suggesting any attempt to study consequences of climate change beyond 2ºC (which is only a few decades away) should be derided as “climate porn”?

  39. Steven Mosher says:

    Hmm not that one.. I will look some more

  40. Hyperactive Hydrologist says:

    What evidence is there that RCP8.5 is an implausible scenario?

  41. vtg,
    Indeed, it seems that emission reductions rely on technologies that we have yet to develop, or yet to implement at any kind of relevant scale. However, the idea that emissions could keep rising is apparently ridiculous. It’s one reason why I would quite Roger to explain the relevance of the Kaya identity and his Iron Law.

  42. Steven Mosher says:

    “You’re suggesting any attempt to study consequences of climate change beyond 2ºC (which is only a few decades away) should be derided as “climate porn”?”

    Here is what I would argue. First off by way of background as much as I liked the SRES approach i now think the RCP approach is better.
    Some principles: you typically want to start with some boundary cases– say best case ( 2.6) and worst case (8.5). You do this for a couple reasons. One is signal to noise, and the other is to get an idea of the variance across the problem space. And of course you want to do some in the middle.

    The boundary case of 8.5 from the policy perspective shows us that we definately dont want to go to the median levels of warming that case presents. On the science side ( looking at S/N issues) I’m not so sure people have detailed the justification, but it made good sense to do it.

    Going forward, IF I OWNED THE CPU CYCLES, I would not waste any more cycles on 8.5.
    If I had time to do 100 runs, you better bet I would split them between 4.5 and 6, maybe toss a few at RCP7 and maybe toss a few at RCP 2.6.

    So, No. i wouldnt even call 8.5 climate porn. smh

  43. Steven Mosher says:

    ‘RCP8.5 is a BaU scenario by any reasonable definition, so that doesn’t make sense. ”

    Only if you define usual unusually.

  44. “what Roger calls climate porn” is that being an “honest broker” or a scientist “seeking to play a positive role in policy and politics”, or is it partisan rhetoric? I guess we’ll never know…

  45. “rogerpielkejr says:

    IPCC retired RCP 8.5 in 2017.
    Climate impacts researchers surely should by 2018.”

    (i) what have they replaced it with, RCP 6.0 looks rather optimistic to me, so presumably there is an RCP 7.5 or an RCP 8.0?

    (ii) how long will it take to generate a new set of model runs from each group for these new scenarios so we have a realistic “business as usual” scenario that climate impact researchers could use instead, given the lead time of their own research? I’m no expert, but I would have though the time taken to change from one set of scenarios to another would be much longer than a year.

  46. Everett F Sargent says:

    ATTP,

    RCP 8.5 (CMIP5 or your figure) …

    SSP RCP 8.5 (CMIP6 per Carbon Brief) …

    As I see it, 8.5 W/m^2 = 8.5 W/m^2 in 2100 (different trajectories but same end result).

    I also happen to think that RCP 8.5 is as if we never thought about AGW to begin with in the 1st place. But then again, we could have 8 years of TrumpTV (in which case we would need an RCP 10.0). 😉

  47. paulski0 says:

    Steven Mosher,

    That’s reasonable. I think the problem with doing 4.5 and 6.0 is that outcomes can be quite similar during the 21st Century, although it depends on the specific form of 6.0 scenario. As shown on Chubbs’ plot above, the 6.0 used in CMIP5 shows lower emissions growth than RCP4.5 during the early 21st Century. It then accelerates and reaches ~6.0 by 2100 on the upswing. The result is that climatic differences by 2100 between 4.5 and 6.0 are small. Look at the AR5 SPM. Warming by 2046-2065 only 0.1ºC separation, by 2081-2100 only 0.4ºC. Sea level rise only 0.01cm difference for both periods. I suspect climate modelling groups might look at doing both as a big waste of resource.

  48. izen says:

    Using any scenario other than RCP8.5 makes the implicit assumption that the global society WILL make significant cuts to its emissions.
    An assumption for which there is scant evidence, and observations that refute it.
    https://scripps.ucsd.edu/programs/keelingcurve/
    And experts in the field who project a continued increase in emissions for at least two decades.
    https://www.ogj.com/articles/print/volume-115/issue-9c/regular-features/editorial/the-future-of-oil.html
    Oil consumption increases through 2040 in EIA’s reference-case model projection-and in higher and lower-price cases, as well. Total energy consumption increases. Consumption growth rates for natural gas and renewable fuels exceed that of oil, but gas doesn’t overtake oil.

  49. Everett F Sargent says:

    I might add that CMIP6 SSP5 RCP 8.5 (the uppermost curve in the Carbon Brief graphic), appears to show higher CO2 emissions than those used in CMIP5 RCP 8.5 (say 125-130 vs 100-105), Scratches head.

  50. paulski0 says:

    Steven Mosher,

    Only if you define usual unusually.

    Nope, the standard definition. See:

    http://www.ipcc.ch/ipccreports/tar/wg3/index.php?idp=286

  51. Steven Mosher says:

    “(i) what have they replaced it with, RCP 6.0 looks rather optimistic to me, so presumably there is an RCP 7.5 or an RCP 8.0?”

    RCP 7 has been added.

  52. Are there any publicly available ensemble outputs available for RCP 7.0 yet, I couldn’t find any, but perhaps I am googling for the wrong thing.

  53. Everett F Sargent says:

    SM sez …
    “Going forward, IF I OWNED THE CPU CYCLES, I would not waste any more cycles on 8.5.”

    But you don’t own the CPU cycles and neither do I, but …
    https://www.wcrp-climate.org/modelling-wgcm-mip-catalogue/modelling-wgcm-cmip6-endorsed-mips

    AerChemMIP- Aerosols and Chemistry Model Intercomparison Project
    C4MIP – Coupled Climate Carbon Cycle Model Intercomparison Project
    CDRMIP – The Carbon Dioxide Removal Model Intercomparison Project
    CFMIP – Cloud Feedback Model Intercomparison Project
    DAMIP – Detection and Attribution Model Intercomparison Project
    DCPP – Decadal Climate Prediction Project
    FAFMIP – Flux-Anomaly-Forced Model Intercomparison Project
    GeoMIP – Geoengineering Model Intercomparison Project
    GMMIP – Global Monsoons Model Intercomparison Project
    HighResMIP – High-Resolution Model Intercomparison Project
    ISMIP6 – Ice Sheet Model Intercomparison Project for CMIP6
    LS3MIP – Land Surface, Snow and Soil Moisture
    LUMIP – Land-Use Model Intercomparison Project
    OMIP – Ocean Model Intercomparison Project
    PAMIP – Polar Amplification Model Intercomparison Project
    PMIP – Palaeoclimate Modelling Intercomparison Project
    RFMIP – Radiative Forcing Model Intercomparison Project
    ScenarioMIP – Scenario Model Intercomparison Project
    VolMIP – Volcanic Forcings Model Intercomparison Project
    CORDEX – Coordinated Regional Climate Downscaling Experiment
    DynVarMIP – Dynamics and Variability Model Intercomparison Project
    SIMIP – Sea Ice Model Intercomparison Project
    VIACS AB – Vulnerability, Impacts, Adaptation and Climate Services Advisory Board

    That’s 23 endorsed MIPS, with only ScenarioMIP (our current discussion of the CMIP6 universe) and SSP5 RCP 8,5 (or a single bin out of at least 25 bins in total) …
    The Scenario Model Intercomparison Project (ScenarioMIP) for CMIP6
    https://www.geosci-model-dev.net/9/3461/2016/gmd-9-3461-2016.pdf

    There are currently ~25 bins of RCP’s and SSP (per the Carbon Brief graphic as posted above, add a very few for RCP 7.0, so maybe ~30 bins in total).

    The next paragraph is literally dripping with sarcasm.

    I wonder if the SME’s had any meetings about what was even doable in their defined time frame? Nah, I seriously doubt they had any meetings at all. Nope they don’t have a clue. They have never run their current state-of-the-art AOGCM’s ESM’s before and thus have absolutely have no idea how many runs they could do. I can’t wait for that WTFUWT? article telling us all how many PW of energy were used in the entire CMIP6 modeling ensemble suites (WE will calculate the GMST from these modeling runs and conclude that all AGW comes from conducting all these numerical modeling runs).

  54. Dave_Geologist says:

    ATTP

    Yes, I do think that many of those who criticise RCP8.5 then promote things that would lead to it being more likely that we’d then follow it.

    Well, a cynical person might think that was entirely the point of the exercise 😉

  55. Thanks for the list Everett, that will come in handy the next time I see the old “climatologists never test their models” canard! ;o)

  56. paulski0 says:

    dikranmarsupial,

    No, nothing from CMIP6 is available yet. From what I understand, they should start to trickle in from end of 2018 but might not be a usable ensemble until the end of the following year.

  57. Hyperactive Hydrologist says:

    I know it has already been mentioned but none of the scenarios include carbon cycle feedbacks. The recent El Nino caused the rainforest regions to become a net source of CO2 rather than a sink. Could this be an indication of what will occur once we hit slightly higher temperatures? We also know that as oceans warm their capacity to dissolve CO2 reduces.

    Another question I have is that if we do develop large scale negative emissions technologies (NETs), as required by all plausible IAM scenarios, do the oceans become a net source of CO2? As NETs draw down the atmospheric CO2 do the oceans give up dissolve CO2 to maintain equilibrium and hence do we need to deploy even more NETs to compensate?

  58. Hyperactive Hydrologist says:

    That should read “plausible IAM scenarios to achieve the 2 degrees target”

  59. Dave_Geologist says:

    Re the differing Scholar percentages. I don’t know if this information is available (probably part of the Google secret sauce), but I get the impression there is cross-talk between Scholar and regular Google. That my Scholar results are influenced by my other Google searches. At least in ranking if not in number.

    I can feel an interesting meta-study coming on for someone. Do the number and/or ranking of Google Scholar searches tell you something about the searcher’s browsing/searching/click history? For example, will someone who regularly clicks through to the non-peer-reviewed hits be fed them preferentially relative to someone who always goes for the peer-reviewed stuff? Hypothetically, for example, might someone who uses Scholar searches for polemical purposes get more hits and have the non-peer-reviewed ones higher-ranked than someone who uses it for science just because they don’t have a Scopus subscription? One might then expect an auditor or honest broker of science, one who has a laser-like focus on science and only science, to have a profile like that of the nerdiest lab-rat.

  60. paulski wrote:

    No, nothing from CMIP6 is available yet. From what I understand, they should start to trickle in from end of 2018 but might not be a usable ensemble until the end of the following year.

    thanks paulski, AFAICS that makes Roger’s assertion:

    rogerpielkejr says:
    May 11, 2018 at 12:37 am
    IPCC retired RCP 8.5 in 2017.
    Climate impacts researchers surely should by 2018.

    seem rather, shall we say, “unreasonable”?

    rogerpielkejr says:
    May 11, 2018 at 12:37 am

    Credibility is enhanced by not over-egging the pudding.
    Seems obvious.

    What, like enhancing the argument against RCP 8.5 by asserting that climate impacts researchers should retire it before the end of 2018 when the ensemble output for RCP 7.0 is not even available? It seems obvious to me that is perhaps “an egg too far”.

  61. > RCP8.5 is a BaU scenario by any reasonable definition, so that doesn’t make sense. Your <1% probability statistic is made up, and certainly doesn't come from the IPCC.

    Interestingly, both memes have been recently peddled by HAS:

    Riahi et al (2011) describes RCP8.5 as a conservative business as usual scenario. Business as usual is defined as no attempt at mitigation and conservative meant the assumptions made within within it were at the 90th percentile. With your excellent statistical knowledge you’d know that it would be reasonable to assume that with quite weak assumptions about independence this means this pathway is exceptionally unlikely in IPCC terms (0−1% probability) even with no mitigation.

    https://andthentheresphysics.wordpress.com/2018/04/27/lewis-and-curry-again/#comment-118225

    Someone, somewhere in the Contrarian Matrix created that meme.

  62. Steven Mosher says:

    “Thanks for the list Everett, that will come in handy the next time I see the old “climatologists never test their models” canard! ;o)”

    no the smart skeptic will look at the huge list and say how can it be used for policy when so many basic diagnostic tests have yet to be done. not fit for purpose yet…

    skeptobot.

  63. paulski0 says:

    Dave_Geologist,

    Well, a cynical person might think that was entirely the point of the exercise

    I think it’s more that they don’t understand enough or care enough about consistency of argument to recognise the contradictions.

    The aforementioned Matt Ridley is a great case-in-point. In November 2014 he wrote a newspaper column which included an argument that consequences outlined by RCP8.5 should be ignored. The basis of that argument, provided by a citation to a solitary paper, was that fossil fuel production is likely to peak just in the next few years. In March 2015 he wrote an article published in two major newspapers which argued the exact opposite: Fossil fuels are abundant and can easily power substantial growth for centuries to come, while also endorsing that as his preferred path. In other words, he believes RCP8.5 is completely plausible and in fact wants it to happen.

    Of course, he would never admit that latter reading of his argument even though it’s factually undeniable. In his mind the steps are: climate change isn’t a problem -> RCP8.5 suggests climate change is a problem -> therefore RCP8.5 can’t be real -> must find reasons to dismiss RCP8.5 -> found one! Done and dusted.

    Completely compartmentalised from his contradictory beliefs about fossil fuel abundance. I believe the phrase is cognitive dissonance.

  64. I point to the list of completed *MIP exercises (there is one in “A Climate Modelling Primer” by McGuffie and Henderson–Sellers from 2005, but it would be nice to have one of those online as well). However there is no answer that will satisfy the smart skeptic if they are not actually interested in the answering, just the questioning.

  65. Steven Mosher says:

    “RCP4.5 and RCP8.5. In fact, when I did a quick search, a lot of the results did use both RCP4.5 and RCP8.5. ”

    they were core tier 1 studies.

  66. Steven Mosher says:

    last i looked 8.5 had co2 ppm at 1100.

    with the current trajectory of renewables its hard to see us topping 600 ppm, but im open to correction.

  67. Interesting thread & comments, to be sure. My favorite is VV suggesting that a critique of RCP 8.5 equates to my support for Trump and the demise of America. Really? For the record, I am in support of climate mitigation policies and anti-Trump, but I guess most of you guys know that. 🙏
    Lots of false claims and statements made on this thread that can be easily addressed by an afternoon looking at the literature, most importantly the idea that RCP 8.5 is a plausible BAU rather than an an extreme, implausible outlier.
    For a good place to start reading, here is a recent critique of RCP 8.5, concluding:
    “RCP8.5 no longer offers a trajectory of 21st-century climate change with physically relevant information for continued emphasis in scientific studies or policy assessments” https://www.sciencedirect.com/science/article/pii/S0360544217314597#!
    I’m happy to discuss all this, find me on Twitter. Thank Ken.
    PS. Kaya and Iron law discussed in Chapters 2 &3 of my book on your shelf, let me know any Qs.

  68. Roger, how can climate impacts researchers retire RCP 8.5 by 2018 if the model ensemble output for the replacement RCP 7.0 is not available until towards the end of 2018?

  69. “there is no answer that will satisfy the smart skeptic if they are not actually interested in the answering, just the questioning.”

    I have decided to identify these folks as bad faith commenters or bad faith operators because to identify them as skeptics smears skepticism. Skepticism is a healthy intellectual approach, even with the ideas that a person is most attracted to, but the people who engage in the endless, repetitive questioning and goal-post-movement are not skeptics, smart or otherwise, they are bad faith actors, trolls, etc.

    I love this website. Thank you so much for the work involved in the background, and a big thank you for setting up in the manner that allows kill file to work. It allows me to think the comments and avoid the folks that I have identified as bad faith actors.

    May 10: 410.52 ppm
    May 09: 410.10 ppm

    MLO back online!

    Mike

  70. Gavin, Simple. Don’t submit studies that only use RCP 8.5. Don’t characterize it as BAU. Don’t issue press releases claiming that the climate impacts in such studies are predictions of our likely future. If the study is about model sensitivity and not prediction, say so, don’t be coy. Users of scenarios have an obligation to understand what they represent. Peer reviewers do also. That RCP 8.5 was an outlier was well known in 2016 and in the literature Jan 2017. There is no good justification for any study today to present RCP 8.5 as BAU. This does not seem complicated.

  71. izen says:

    Those that follow this in more detail will be able to correct my errors in this. I am under the (mis?)apprehension that anything other than RCP8.5 involves at least a slow down in rising annual emissions amounts, if not a halt to any further increases. Some will require an actual reduction in the amount emitted and carbon capture/negative emission technologies.

    I am sure all these representative pathways are invented by the best minds…

    Meanwhile, when I scout around the business media that specialises in the energy sector, or look at the projections made by energy companies, they all predict increasing consumption. Obviously they have a bias, ‘stranded assets’ is an existential threat to that sector. But they also have the track record, expertise and economic/political clout to make their projections of future emissions more accurate than the IPCC pathways.

    Has anyone tried to combine the projections of FF consumption made by the industry, which envisions continued increases in annual emissions for at least the next 20 years, with modulz?

  72. Dave_Geologist says:

    Paul, well, yes, “cognitive dissonance”.

    Absent mind-reading skills, it’s a moot point whether someone knowledgeably or subconsciously jumps to the links he likes and ignores the ones he doesn’t like it, or whose author is enough to indicate he won’t like it.

    And the nature of climate (or any other) science is that contrarians or deniers will have to search hard for stuff they like in the peer-reviewed literature, but will find it in abundance in the grey literature, newspapers and blogs. So their hits ought to be skewed. In the same way certain polar bear referrals were.

  73. Roger,
    A few comments.
    1. If people define BAU as a hypothetical scenario whichs take no account of climate change, then something like RCP8.5 may well be what this is. It’s what happen if we did nothing. It may be unrealistic, and I realise that you disagree with its use, but disagreement is allowed (despite your apparent insistence that people do as you say).

    2. Yes, people shouldn’t use RCPs and then claim that the impacts in such studies are predictions of our likely future. Wonder how often this actually happens (and, “if we do …., this might happen” is not a prediction)?

    3. RCP8.5 can be a useful scenario for two reasons that have been explained a number of times.

    3i. It provides a way to better distinguish the signal from the noise and hence to estimate the forced response versus internal variability.

    3ii. It passes through the level of changes associated with the other RCPs and hence can also be used to estimate the impact of changes in forcing that are lower than RCP8.5.

    4. Although there are some studies that only use RCP8.5, many use RCP8.5 *and* RCP4.5.

    If you have some time, I would also be interested in you explaining the relevance of the Kaya Identity and your Iron Law.

  74. Prof Pielke Jr “Simple. Don’t submit studies that only use RCP 8.5.

    Not so simple. If they were to stop doing that now, it would mean not publishing anything for a year or two until a sufficient amount of RCP 7.0 runs were available, or not publishing anything on an RCP that represented a “worst case” scenario that RCP 7.0 is presumably supposed to represent. Neither course of action is reasonable. Continuing to publish RCP 8.5 until RCP 7.0 is established would seem more sensible, giving caveats about the representativeness of RCP 8.5 as they see fit, as scientists generally do.

    Users of scenarios have an obligation to understand what they represent.

    Likewise readers of journal papers on these topics, if RCP is unrealistic that does not mean it is of no use in projecting future changes in climate, as we can mentally interpolate between RCPs. I don’t think RCP 8.5 is any more unrealistic than RCP 2.6, I think the political/economic chances of the latter happening are vanishingly small, but I don’t hear anyone complaining about it being used – although it is possible I am not listening in the right places.

  75. BTW Prof. Pielke Jr, I don’t know whether the “Gavin” was a subtle objection to my use of “Roger” (if so, I apologize) but if someone uses a pseudonym online, it is generally good manners to respect it, unless you have a prior agreement with them. In my case, I don’t make any secret of my real name, however some people are actually seeking anonymity, sometimes with good reason, even if the unscrupulous have “outed” them already.

  76. Ken,

    On this odd statement: “despite your apparent insistence that people do as you say.”
    Of course, no one need do anything I say (well, my kids do), & I don’t think I’ve ever said otherwise. It’s a discussion. I’ve got opinions, you’ve got opinions. Agree to disagree is fine.
    OK, perfectly clear?

    I think we’ve exhausted the RCP 8.5 discussion.

    Kaya and Iron Law:
    Kaya –>
    CO2 emissions = population * per capita GDP * energy intensity * carbon intensity
    or simplified, CO2 = GDP * technology (i.e., of energy consumption and production)

    Iron Law says that we are not going to reduce CO2 by intentionally reducing GDP.
    We’re just not, it’s not even worth debating.

    So, the only lever that we have is technology (specifically, intentionally modulating EI of GDP and CI of energy)
    Do some math and you’ll find that reductions in EI of GDP are important (not just for emissions but also for economic growth) but won’t be the major factor in achieving CO2 stabilization at low levels. That leaves CI of energy as the biggest, most important lever.

    How do we measure progress? Not simply CO2 emissions, but CO2/GDP, a reduction of which is called “decarbonization of the economy” — needs to be ~>6% per year. This century we are at ~1.4%.

    For an expanded discussion of these same points, Ch 2&3 of TCF.

  77. Dave_Geologist says:

    rogerpielkejr

    https://andthentheresphysics.files.wordpress.com/2015/07/rcps.jpg?w=584&zoom=2

    rather seems to indicate that RCP6 has left the stable while the door was open.

    To quote AR5, “Scenarios without additional efforts to constrain emissions (‘baseline scenarios’) lead to pathways ranging between RCP6.0 and RCP8.5.” RCP8.5 is needed to constrain the upper bound, so it should pretty much always be run. To do otherwise would be irresponsible. Are you advocating irresponsibility?

  78. dikranmarsupial,
    Sorry for using your name.
    Our Twitter interactions have been on a first name basis (fine by me, BTW), hence my confusion.
    Won’t happen again.

  79. izen says:

    @-dikran
    “I don’t think RCP 8.5 is any more unrealistic than RCP 2.6, I think the political/economic chances of the latter happening are vanishingly small, …”

    And requires the invention of ‘magic’ technology to make CC possible on the scale required.

  80. Roger,

    On this odd statement: “despite your apparent insistence that people do as you say.”

    Maybe I was over-interpreting your “Don’t submit studies that only use RCP 8.5. Don’t characterize it as BAU.”

    What you’re saying about the Kaya Identity and the Iron Law is roughly as I understand it.

    Iron Law says that we are not going to reduce CO2 by intentionally reducing GDP.
    We’re just not, it’s not even worth debating.

    Okay, we want economic growth; people want to see benefits (correct me if this isn’t what you’re implying). Even in your book (page 62) you have a section on “The World Needs Vastly More Energy”. Fine, I agree, economic progress requires energy and if we want more and more of the world’s population (as I would) to enjoy the kind of lifestyles that we enjoy, then this will require generating more energy that we do today, and would require continued economic growth.

    Not simply CO2 emissions, but CO2/GDP, a reduction of which is called “decarbonization of the economy” — needs to be ~>6% per year. This century we are at ~1.4%.

    Indeed, we’re not even close.

    So, when you highlight the Kaya Identity and the Iron Law, how it is often interpreted (in my view) is that we are going to continue growing the global economy and that the level of decarbonization that would be required to achieve some of the climate goals is far greater than we’re currently achieving. In other words, getting emissions to reduce and eventually get to zero is going to be difficult, far more difficult than some suggest.

    However, at the same time you publicly bash those who use RCP8.5.

    This seems broadly inconsistent. People who make claims about how easy it will be to decarbonize are engaging in wishful thinking. Anyone who uses a scenario in which emissions keep rising is reducing the credibility of their discipline and promoting climate porn. One might almost think that you’re simply looking for things to criticise?

  81. Roger, no problem, glad I hadn’t caused offense, just keen for ano/pseudo-nymity to be preserved for those who really want/need it. My intention was to use my real name for things where my academic expertise (such as it is) is relevant and to use DM for things were it isn’t, but the distinction was difficult to maintain (and these days most blogs have problems with sock-puppeting and so only allow one id).

  82. > My favorite is VV suggesting that a critique of RCP 8.5 equates to my support for Trump and the demise of America.

    And mine is the “<1% scenario (says IPCC)" whence the scenarios don't cover a probability range:

    Projections of future climate change are not like weather forecasts. It is not possible to make deterministic, definitive predictions of how climate will evolve over the next century and beyond as it is with shortterm weather forecasts. It is not even possible to make projections of the frequency of occurrence of all possible outcomes in the way that it might be possible with a calibrated probabilistic medium-range weather forecast. Projections of climate change are uncertain, first because they are dependent primarily on scenarios of future anthropogenic and natural forcings that are uncertain, second because of incomplete understanding and imprecise models of the climate system and finally because of the existence of internal climate variability. The term climate projection tacitly implies these uncertainties and dependencies. Nevertheless, as greenhouse gas (GHG) concentrations continue to rise, we expect to see future changes to the climate system that are greater than those already observed and attributed to human activities. It is possible to understand future climate change using models and to use models to characterize outcomes and uncertainties under specific assumptions about future forcing scenarios.

    http://ipcc.ch/pdf/assessment-report/ar5/wg1/WG1AR5_Chapter12_FINAL.pdf

    Anyone quoted by the Contrarian Matrix who claims something probabilistic about scenarios may have access to a Magic Eigth-Ball the IPCC does not.

    My second is caricaturing what VeeV said to rip off one’s shirt, i.e. that RCP 8.5 may not be that implausible considering the actual presidency, and that to “attack scientists for what the press does” amounts to more ClimateBall,

  83. paulski0 says:

    rogerpielkejr,

    There is no good justification for any study today to present RCP 8.5 as BAU. This does not seem complicated.

    No one is claiming that your point is complicated. What’s being said is that your point isn’t valid. RCP8.5 is a BaU scenario by the actual widely-accepted definition of a BaU scenario, even if not by whatever you’ve decided BaU should mean. No amount of attempts to impugn the reputations of scientists can change that.

    For a good place to start reading, here is a recent critique of RCP 8.5, concluding…

    I’ll take a look but I’ve read similar supply-side critiques before, none of which have been compelling. One key issue, which also seems to apply to the paper you’ve linked, is that if they’re correct they’re really burying the lede. Because the implication of their argument is that, without a huge ramping up of renewables (which I’m sure similar types of supply-side analysis would also find to be implausible), the second half of the 21st Century is going to be a period of declining energy supply with a population of around 10 billion.

  84. Ken:
    Just as doctors don’t spend a lot of time with healthy people, policy scholars don’t spend a lot of time on policies that are working.

    RCP 8.5 is among several big issues in IA scenarios and models that have warped our thinking about climate policy and politics. Some apparently believe that overstating things has no downside, as they seem to believe that erring on the side of alarm will scare people into action. The evidence suggests that such tactics don’t work, and may backfire. So yes, presenting RCP 8.5 as BAU has consequences IMO, and not in favor of action. Others may disagree, no worries.

    More criticism? You bet:
    Scenarios that rely on BECCS are fantasy. Like a narcotic in climate policy. As bad or worse than RCP 8.5. Climate policy can’t work as projected without the massive deployment of fictional technologies at global scale. Seriously, why does this persist? Emperor’s new clothes situation if there ever was one.

    Even more criticism? More technical, but assumptions of spontaneous decarbonization are the original narcotic in IAMs. Dulls the senses, and makes everything seem OK. Again, reliance on such assumptions does not favor action.

    So yes, criticism is warranted (and I could go on, temperature overshoot, energy access…). As I am sure you are aware, such criticism is in some circles not welcomed, must show a united front against the bad guys or something. I think its better to get things right. Effective policy depends on it.

    More details on all this in this PDF (a paper in the works):
    https://drive.google.com/open?id=0B92CyI7iP9pqdjlxX0RLUFZHczVFRERtdXhmZ3hvYzd0T1BF

  85. Magma says:

    Excluding AR5, the two most cited (Web of Science metrics) papers referencing RCP 8.5 are both open access. It may be worth going back to them rather than relying on potentially biased second or third-hand accounts of what they stated.

    Meinshausen et al. (2011) The RCP greenhouse gas concentrations and their extensions from 1765 to 2300, Climatic Change

    Riahi et al. (2011) RCP 8.5—A scenario of comparatively high greenhouse gas emissions, Climatic Change

    The RCP8.5 combines assumptions about high population and relatively slow income growth with modest rates of technological change and energy intensity improvements, leading in the long term to high energy demand and GHG emissions in absence of climate change policies. Compared to the total set of Representative Concentration Pathways (RCPs), RCP8.5 thus corresponds to the pathway with the highest greenhouse gas emissions.

  86. Well, at least this got Bill interested:

    and

  87. Roger,
    Don’t get me wrong, I think criticism is often warranted (I engage in it myself, as should be obvious). Might be nice if it was constructive, but that’s up to you.

    However, the point I was getting at (which I don’t think you’ve really addressed) is that if decarbonization is going to be very difficult, if some of the potentially required technologies are unlikely to work (BECCS) and if we are going to need vastly more energy in future than we use today, then RCP8.5 does not seem as unlikely as you seem to claim. The emissions are about 3 times higher than they are today.

    For clarity, though, my own view is that decarbonization will indeed be difficult and that some of what is included in some of the scenarios (BECCS) are indeed technologies that are unlikely to work at scale. I also think, however, that an emission pathway consistent with RCP8.5 is also unlikely, partly because we will probably soon realise how stupid it would be to follow such a pathway, and partly because we are more innovative than we sometimes give ourselves credit for (we will probably find some kind of solution/solutions).

    However, I have no real problem with people using a pathway that may be possible, but unlikely. Partly for the reasons already pointed out, and partly because it is worth highlighting what could happen if we don’t do something to avoid this pathway. Additionally, there are carbon cycle uncertainties that mean that we could still follow an RCP8.5 concentration pathway, even if we follow an emission pathway typically associated with a lower RCP. Again, I think your apparent confidence in RCP8.5 being a completely unrealistic pathway is somewhat over-stated (IMO).

  88. Dave_Geologist says:

    rogerpielkejr
    Why do climate change scenarios return to coal?
    Donald Trump? Matt Ridley? I know you don’t support the former, but he is US President and his fans think he’ll do 8 years. And if he gets a couple more conservative Supreme Court judges in place, US climate action will be hamstrung for decades by lawsuits which will be looked on more favourably in the SC than in previous decades.

    So no, I don’t agree RCP8.5 is unreasonable. There are powerful people who very much want us to go there, and as long as they have power or the potential for power, the world has a right to know what RCP8.5 outcomes look like.

  89. izen says:

    Allways a little wary of using Wiki, but it does provide a ranked global list of GDP:CO2 ratios.

    This ratio measures the degree of decarbonization with a metric called Technology ?

    https://en.wikipedia.org/wiki/List_of_countries_by_ratio_of_GDP_to_carbon_dioxide_emissions

    The three largest emitters, China, US, EU, have very different ratios, the EU is 7x China. It is less obvious this is because of a difference in Technology.
    Individual cases are even more indicative that decarbonisation may be a little more complex than a result of Technology. Compare Poland and Ireland, or Norway and Australia.

  90. Dave_Geologist says:

    I think we’ve exhausted the RCP 8.5 discussion.

    You’re in a hole roger. You’re right, time to stop digging.

  91. Everett F Sargent says:

    Yeah, Roger just convinced me that RCP 8.5 is a real possibility. Also, pointing to papers by Ritchie and Dowlatabadi, not a good move, like them saying we are on this ‘so called’ decarbonization trend …

    Defining climate change scenario characteristics with a phase space of cumulative primary energy and carbon intensity
    http://iopscience.iop.org/article/10.1088/1748-9326/aaa494
    “This orientation runs counter to the experienced ‘dynamics as usual’ of gradual decarbonization, suggesting climate change targets outlined in the Paris Accord are more readily achievable than projected to date.”

    Carbon emissions are projected to increase by 2% in 2017. So how can we recarbonate when we have never decarbonated to begin with in the 1st place. 😦
    https://www.carbonbrief.org/analysis-global-co2-emissions-set-to-rise-2-percent-in-2017-following-three-year-plateau

    Now if we had data for several decades showing total fossil fuel use going down then, and only then, would I call that true decarbonization.

    Fossil-fueled development (SSP5): An energy and resource intensive scenario for the 21st century
    https://www.sciencedirect.com/science/article/pii/S0959378016300711?via%3Dihub
    • The SSP5 scenarios mark the upper end of the scenario literature in fossil fuel use, food demand, energy use and greenhouse gas emissions.
    • The SSP5 marker scenario results in a radiative forcing pathway close to the highest Representative Concentration Pathway (RCP8.5)..
    • An investigation of mitigation policies in SSP5 confirms high socio-economic challenges to mitigation in SSP5.
    • In SSP5, ambitious climate targets require land based carbon management options such as avoided deforestation and bioenergy production with CCS.
    • The SSP5 scenarios provide useful reference points for future climate change, impact, adaption, mitigation and sustainable development analysis.

  92. paulski0 says:

    izen,

    Those that follow this in more detail will be able to correct my errors in this. I am under the (mis?)apprehension that anything other than RCP8.5 involves at least a slow down in rising annual emissions amounts, if not a halt to any further increases. Some will require an actual reduction in the amount emitted and carbon capture/negative emission technologies.

    I’d say not exactly. At the low end the range of scenarios suggests you could potentially get something like RCP6.0 with continuing emissions increases and no specific mitigation policy.

  93. > I also think, however, that an emission pathway consistent with RCP8.5 is also unlikely, partly because we will probably soon realise how stupid it would be to follow such a pathway, and partly because we are more innovative than we sometimes give ourselves credit for (we will probably find some kind of solution/solutions).

    [America] Hold my beer:

    [Japan] Hold my sake:

    I’d bet on our sense of innovation more than our common sense. I still believe in our sense of decency, but it’s hard to make it reach tops of hierarchies. It needs to come from bottom up. This takes time we may not have.

  94. The Very Reverend Jebediah Hypotenuse says:

    When we crash crash-test-dummies in cars, we always toss the data from the high-speed runs.

    Keeping that data would of cause regular folks to worry way too much about driving too fast – some of them might even slow down, or worse yet, convince car manufacturers to make safer cars.

    We call it the de-cautionary principle.

  95. Jai Mitchell says:

    I would like to note here that the MAGICC ESM model used by multiple independent teams to determine remaining carbon budgets only projects a net emissions from carbon cycle (natural) sources of 55 Billion Tonnes under RCP 6.0. This scenario currently is expected to limit warming to 4.0C.

    However, multiple field studies and long-time series studies in the field indicate that under only 2.0C of warming we will experience over 300 Billion Tonnes of Carbon released from the Earth’s soils in only 35 years, with much greater emissions locked in from deeper soils and from mid-latitude forests.

    Finally, the MAGICC ESM projects that future carbon sink activity will be just as strong as it is today through 2100. However we are already observing declining carbon sinks globally.

    Therefore, these RCPs, which fameously do NOT include ANY emissions from melting permafrost AND severely understate the carbon cycle feedbacks & loss of carbon sinks under future warming SIGNIFICANTLY understate atmospheric forcing, (since these natural emissions are not included).

    A rough projection of the field study work indicates that under 4C of warming, the Earth will emit a NET POSITIVE emissions of carbon to the atmosphere that is equal to the entire anthropogenic carbon footprint since 1880 (154 ppmv CO2).

  96. Everett F Sargent says:

    ATTP said …
    “Additionally, there are carbon cycle uncertainties that mean that we could still follow an RCP8.5 concentration pathway, even if we follow an emission pathway typically associated with a lower RCP.”

    Yes! LULC, the ocean and land CO2 sinks. So, even without massive increases in coal use, we could still see significance aCO2 increases that replace those higher anthropogenic CO2 emissions under lower RCP’s.

  97. Jai Mitchell says:

    addendum,

    This means that RCP 6.0 is actually closer to RCP 8.5 and RCP 4.5 is closer to RCP 6.0

    There is no scenario that will produce RCP < 3.5

  98. BBD says:

    Jai’s is at least the second, possibly third comment pointing to carbon cycle feedbacks, something I fear is being overlooked in the hyperfocus on human emissions scenarios.

  99. > LULC, the ocean and land CO2 sinks

    My kingdom for a Land Use Land Zoology.

    Any other Z would do.

  100. Bill makes an important point over teh Tweeter:

  101. Everett F Sargent says:

    Well this was not very helpful …
    “More details on all this in this PDF (a paper in the works):”

    Slide 33 …
    “An alternative is to focus on today-forward planning
    – We are at 16% carbon-free global energy consumption, how do we get to >90%?
    – We consume 11,000 mtoe of fossil fuels per year, how do we get close to zero?”

    So today-forward planning is all about asking two questions. A good today-forward planning paper would purportedly provide some answers in the form of today-forward planning scenarios. Let us all call these today-forward planning scenarios “Shared Socioeconomic Pathways” (or SSPs). Yeah, that’s the ticket.

    Even better, let’s start up an organization and call it something like … wait for it … the IPCC!

  102. We are using less coal. The world’s population is not increasing as fast as RCP 8.5 anticipated. Technology is being used effectively to come up with real innovations to spur decarbonization, even without CCS.

    Each of the core assumptions employed in game-planning a trajectory towards RCP 8.5 have been invalidated. That is why it has been abandoned. In order to revive it, one would need to come up with new, better assumptions. I haven’t seen that in this thread.

    It may be useful to recall that the Representative Concentration Pathways were commissioned to provide inputs to climate models. Finding real world methods of reaching those totals happened after the fact and the authors of each of the pathways explicitly counseled against using them as real world predictions, projections or even plausible scenarios.

  103. > Each of the core assumptions employed in game-planning a trajectory towards RCP 8.5 have been invalidated.

    Citation needed, for both the core assumptions and the invalidation.

  104. Because, as Nic says, we need better observations:

  105. The Very Reverend Jebediah Hypotenuse says:


    That is why it has been abandoned.

    Petitio principii – at 12 o’clock!

  106. Everett F Sargent says:

    “That is why it has been abandoned.”

    Nope.

    Read the thread, SSP5-RCP8.5 is still there and still at 8.5 W/m^2.

    RCP 1.9, 2.6, RCP 3.4, RCP 4.5, RCP 6.0, RCP 7.0 and RCP 8.5. That’s seven RCP’s intermingled with five SSP’s. Will we follow any of them? Nope. But IMHO, I happen to think that RCP 8.5 is way more likely than RCP 1.9.

  107. Hyperactive Hydrologist says:

    According to N&C18 anthropogenic forcing up to 2016 is 2.8 W/m^2. That is about approximately a decade ahead of the forcing prescribed in the RCP 8.5 scenario database.

  108. Hyperactive Hydrologist says:

    Sorry the should be L&C18.

  109. Everett F Sargent says:

    World population RCP 8.5 (CMIP5) 12 billion in 2100.

    UN population projection 11.2 billion in 2100 (central estimate). 11.2/12 = 92.3% (so really off by 7.7%).

    The World Population Prospects: 2015 Revision
    http://www.un.org/en/development/desa/publications/world-population-prospects-2015-revision.html
    https://esa.un.org/unpd/wpp/Publications/Files/Key_Findings_WPP_2015.pdf

  110. Steven Mosher says:

    if you want to play the carbin cycle bogey man then do so formally in the rcps

  111. Dave_Geologist says:

    Hmmm. Google Scholar.

    Search for RCP 8.5 returns 24,600 hits
    Search for RCP 6.0 returns 18,300 hits
    Search for RCP 4.5 returns 41,300 hits
    Search for RCP 2.5 returns 55,600 hits
    Search for RCP 4.5 AND RCP 8.5 returns 15,200 hits
    Search for RCP 4.5 AND RCP 6.0 AND RCP 8.5 returns 14,600 hits
    Search for RCP 2.5 AND RCP 4.5 AND RCP 6.0 AND RCP 8.5 returns 9,930 hits
    Search for RCP 6.0 AND RCP 8.5 returns 19,700 hits
    Search for RCP 8.5 -6.0 returns 18,300 hits (= NOT 6.0 in boolean terms; I did a check and it only applies to 6.0 as a standalone word, so doesn’t exclude 2060 for example)
    Search for RCP 8.5 -4.5 returns 10,500 hits
    Search for RCP 8.5 -6.0 -4.5 returns 8,780 hits
    Search for RCP 8.5 -6.0 -4.5 -2.5 returns 5390 hits
    Search for RCP 2.5 -4.5 -6.0 -8.5 returns 24,000 hits

    So I draw a couple of conclusions.

    1) Mosh’s call/demand/suggestion has already been acted on without his input. The biggest hit is indeed RCP 2.5. Good to see so many people are working on conditions many of us will see in our lifetimes.

    2) Roger’s fox is well and truly shot.
    a) RCP8.5 only ranks third and a close third at that, not far ahead of fourth, with the most optimistic RCP 2.5 the clear winner.

    b) Most of the RCP 8.5 hits (78%) also mention another RCP, with 6 and 8.5 the winner. Hey, these climate guys are pretty smart, they focus their attention on the two scenarios which bracket the most likely pathway!. Who’da thunk it?

    c) Only 22% of the hits which mention RCP 8.5 don’t mention one or more of the other RCPs. I guess porn ain’t what it used to be in the climate world. Looks like it’s pretty unpopular.

    d) There are almost as many hits for RCP 2.5 on its own as there are for RCP 8.5 with or without another RCP. There are four or five times as many hits for RCP2.5 on its own as there are for RCP 8.5 on its own.

  112. > I guess porn ain’t what it used to be in the climate world.

    But in the intellectual dark web, however:

    Coincidence? You be the judge!

  113. SM “if you want to play the carbin cycle bogey man then do so formally in the rcps”

    except then they wouldn’t be scenarios as the carbon cycle feedback is part of the model, not the input to the model.

  114. Joshua says:

    Willard –

    The stars of Bari Weiss’ “Dark Web” all have one thing in common (with her): they love to mock & scorn marginalized people for their “victimhood,” while whining as self-pitying victims & martyrs because they have to endure criticisms on their big platforms. It’s just pitiful.

    Why would you post that here, given that there’s no conceivable connection to the discussion in this thread?

  115. Joshua says:

    Roger –

    I am of the opinion that terminology such as “climate porn” is likely to contribute to the degrading the qualify of discussion related to climate change – and use of that term is inconsistent with your goal of elevating the discussion.

  116. Undoubtedly because, squirrels, Joshua:

  117. Oh, and do read that ClimateBall thread, wherein RichardB needs to instruct contrarians that the C in RCP stands for concentration.

    There’s something about contrarians, ClimateBall, and concentration.

    ***

    Once again, Zeke for the win:

  118. Magma says:

    @ Willard

    I expect we’ll see public outrage about the defunding of NASA’s Carbon Monitoring System coming from both Pielkes, Curry, Christy, Spencer, Tol and Lomborg. Because objective scientific data, amiright?

  119. paulski0 says:

    thomaswfuller2,

    We are using less coal.

    Coal consumption to date is in-line with RCP8.5 as far as I’m aware.

    The world’s population is not increasing as fast as RCP 8.5 anticipated.

    I don’t think that’s true, but it’s irrelevant anyway. The CMIP6 RCP8.5 actually has the lowest population growth. As did the equivalent to RCP8.5 in the SRES.

    Technology is being used effectively to come up with real innovations to spur decarbonization, even without CCS.

    Vague, and assumes things which haven’t happened yet.

    It may be useful to recall that the Representative Concentration Pathways were commissioned to provide inputs to climate models. Finding real world methods of reaching those totals happened after the fact…

    This is a misrepresentation. The spread of RCPs was defined by the pre-existing literature on plausible scenarios.

    In order to revive it, one would need to come up with new, better assumptions. I haven’t seen that in this thread.

    There seems to some attempt to cast RCP8.5 as some mystical thing full of complex assumptions. It’s really very simple. If energy demand grows strongly, there aren’t enough non-fossil fuel sources to satisfy a decent fraction of that demand, and there is enough fossil fuel availability we will hit something close to RCP8.5.

  120. Please, PaulS. Don’t criticize too much, otherwise we’ll have moar shirt ripping.

  121. rogerpielkejr says: “Interesting thread & comments, to be sure. My favorite is VV suggesting that a critique of RCP 8.5 equates to my support for Trump and the demise of America.

    I hope you never called yourself an Honest Broker. What I wrote was:

    There is no suggestion in there about your politics about which I am completely oblivious. I do hope that you as political scientist are aware there is an irresponsible person sitting in the White House who is working to make RCP8.5 a reality, while money from his American, foreign and amoral donors flow into his bank accounts and those of his lawyers. Even just as a normal citizen I would have expected that you are aware of the political preferences of the majority of your Twitter followers.

    There is a term for this.
    https://yourlogicalfallacyis.com/strawman

  122. Everett F Sargent says:

    So in reviewing someone’s (RPJr) presentation I found this on Slide 22 …
    ““As the SSPs systematically cover plausible combinations of the primary drivers of emissions, this finding suggests that 8.5 W/m2 can only emerge under a relatively narrow range of circumstances.”
    (in only 1 of >100 scenarios)”

    This part, “As the SSPs systematically cover plausible combinations of the primary drivers of emissions, this finding suggests that 8.5 W/m2 can only emerge under a relatively narrow range of circumstances.” can be found here as it is a direct quote …
    The Shared Socioeconomic Pathways and their energy, land use, and greenhouse gas emissions implications: An overview
    https://www.sciencedirect.com/science/article/pii/S0959378016300681

    The made up part or fake part or made up 713 “(in only 1 of >100 scenarios)” is nowhere to be found as a count or as a probabilistic statement. See Table 1 of the main paper and Table 2 of the SOM, in total six groups conducted a total of 106 runs, four groups ran SSP5-RCP8.5 (aka SSP5-Reference) and two groups did not even try to run SSP5-RCP8.5.

    Thus, these are just model rums and I predict that all six groups could of run SSP5-RCP8.5, but four tried and those four succeeded for a p=1.0.

    In other words the “(in only 1 of >100 scenarios)” added by RPJr is totally bogus! 😦

  123. The Very Reverend Jebediah Hypotenuse says:


    What about the other ways in which RCP8.5 is unrealistic, and its over-use, as @RogerPielkeJr points out? Does anybody really think we will be burning 10x as much coal in 2100?
    Does anybody really think we will be burning 10x as much coal in 2100?

    Did anyone living in 1918 ever think that the Earth’s atmosphere would contain over 400 ppm CO2 by 2018?

    Did anyone investing in Northern Rock during the 1990s ever imagine that it would be nationalized in 2008.

    Matt Ridley’s musings on “unrealistic” scenarios are something to be cherished.

  124. paulski0 says:

    Everett F Sargent,

    Interesting. As Willard alluded to, that’s the exact mistake HAS made recently when also claiming RCP8.5 has <1% probability.

    What the text of the original paper actually says is that only one of the five SSPs produces a pathway similar to RCP8.5. Not ‘only 1 of the >100 scenarios’.

    For those keeping score, it’s also the case that only one of the five SSPs produces a pathway as low as RCP6.0. So I guess that’s out too.

  125. verytallguy says:

    Victor,

    RPJ’s representation of your tweet is a thing of beauty.

    The train wreck that is climateball never ceases to amaze.

  126. BBD says:

    Steven

    if you want to play the carbin cycle bogey man then do so formally in the rcps

    What Dave G said, but I’d add that pretending that the carbon cycle is a fictional being created for the purpose of scaring children illuminates your position more clearly than is tactically desirable.

  127. paulski0 says:

    Steven Mosher,

    last i looked 8.5 had co2 ppm at 1100.

    with the current trajectory of renewables its hard to see us topping 600 ppm, but im open to correction.

    By 2100? CMIP5 8.5 is just shy of 950ppm. CMIP6 8.5 hits 1050ppm.

    The current trajectory of CO2 emissions has them following RCP8.5. Maybe they aren’t mutually exclusive. RCP8.5 had the highest growth in renewable energy production of the CMIP5 scenarios.

  128. I find it curious that , jaded with mere catastrophe, some CMIP & GeoMIP exercises, e.g.

    https://tinyurl.com/y8mprft5

    have gone beyond the forcing regime of RCP8.5 , to operate on “idealized” futures featuring 1,600 ppm CO2.

    One would think the IPCC 1,250 ppm eq.CO2 ceiling scary enough for government work, but then, 8.5’s are where you find them.

  129. Willard says:

    Searching for where Junior’s meme came from, I stumbled upon this gem:

    [S]cientists skeptical of catastrophic warming have been pointing this out for years. Former Cato Institute climate scientist Chip Knappenberger often pointed out that RCP 8.5 is not “business as usual.”

    http://dailycaller.com/2017/12/06/scientists-claim-an-exceptionally-unlikely-global-warming-scenario-could-be-worse-than-expected/

    Not sure where Michael got that Chip was a climate scientist, but nevermind.

    What matters here is that his newsie has been posted on 2017-17-06, and refers to Chip’s tweet, dated 2015-09-28:

    This gives a good idea where to look. First hit from that Freedom Fighters’ think tank:

    It’s not surprising that those making the case for climate action most frequently reference the highest (RCP8.5), embedding it in most climate scenarios, assessments, and international agreements (the Paris Agreement being a prime example). Here is a summary of Google Scholar citations for the different RCPs, published on February 9 by Eric Roston in Bloomberg:

    [Insert the graph Junior tweeted]

    RCP8.5 is obsolete. It was obsolete when it was first published in the journal Climate Change by Riahi et al. in 2011. By then the shale gas revolution was underway, as can be seen from the plot below of shale gas production. By 2011, abundant shale gas had begun a wholesale displacement of coal for electrical generation, increasing natural gas’s portion of our energy portfolio and decreasing that of coal.

    https://www.cato.org/blog/time-cool-it-uns-moribund-high-end-global-warming-emissions-scenario

    The blog post ends with the obligatory Roy cameo.

    I’m starting to think Roy is the Stan Lee of the Contrarian Matrix.

  130. Willard says:

    The previous CATO blog was 2018-02-28. Here’s a more recent one:

    The largest projections of future warming are driven by an emissions scenario we recently debunked, known as RCP 8.5. We noted that researchers at the University of British Columbia recently found there is simply not enough coal (recoverable or otherwise) to make these outcomes physically possible. In the Wall Street Journal, the Manhattan Institute’s Oren Cass takes a similar look at the failure of worst-case scenarios to account for human ingenuity and adaptation—calling them “laughably bad economics.” It’s based on a detailed report you can download here

    Same ClimateBall narrative as in Junior’s newsletter published at Tony’s, with the added “and Oren.” Oren is a name that rings a bell. Where did I hear it last time? Right:

    And before that, it was at AT’s, which refers to Oren’s WSJ’s hit piece. From a comment of mine:

    I was wondering about who Oren Cass was. His tweeting bio reads: Senior Fellow @ManhattanInst. Domestic Policy Director @MittRomney 2012.

    https://andthentheresphysics.wordpress.com/2018/03/14/ignoring-adaptation/#comment-113277

    So our merry-go-round into the Contrarian Matrix gives this first approximation: Junior, Tony’s, the Editor, Chip, Cato, Bloomberg, WSJ, Oren, the Manhattan Institute, Judy, Ted, and teh Donald’s Congress.

    What a tangled web the Dark Web of ClimateBall weaves.

  131. paulski0 says:

    I do like the idea that the shale gas revolution definitively increasing the availability of fossil fuels for burning somehow reduces the probability of a high emissions scenario.

  132. Willard says:

    Indeed, PaulS, and adding caltrates will return us to a pre-industrial climate.

    Vintage 2015-12-13:

    > They include the dread words, “business as usual”. Maybe they shopuldn’t have. But they are making the status of RCP8.5 as the top end of the range perfectely clear.

    Since the Editor recommends NG and that NG refers to 8.5 as one of the BAUs, I duly submit that the Editor’s dread is only fabricated to dramatize his favorite meme. See here:

    http://climatechangenationalforum.org/what-is-business-as-usual/

    https://judithcurry.com/2015/12/13/a-closer-look-at-scenario-rcp8-5/#comment-751251

    I thought this counts as a ClimateBall KO.

    ***

    So our Editor is onto RCP 8.5 since at least 2015. Interestingly, he’s also fond of Senior. See for instance that 2018-05-22 post, the only time I recall having visited the Editor’s. I’ll quote this point of mine, if only for Joshua’s eyes only

    My point is this: one does not simply whine about tone one day and then use snark the other day and expect to be taken seriously in Mordor. This smarmy behavior amounts to victim playing. I expect this kind of diversion from an amateur commenter, not from one of the most important quarterbacks in ClimateBall history. Senior used this trick so often over the years that he could trademark it.

    https://fabiusmaximus.com/2015/05/22/climate-science-debate-84789/

  133. Willard says:

    Why, of course AT has covered the Editor’s post at Judy’s:

    Fabius Maximus has a guest post on Climate Etc. in which he focuses on RCP8.5. RCP8.5 is a Representative Concentration Pathway (RCP) that leads to a change in forcing of 8.5Wm-2 in 2100. Focusing on this particular RCP seems to be a bit of a theme at the moment. There appears to be two basic arguments. Those who describe RCP8.5 as business as usual (BAU) are wrong (and probably activists), and we should be assigning probabilities to the emission pathways associated with the various RCPs.

    […]

    However, assigning probabilities to the emission pathways associated with the different RCPs seems more problematic.

    https://andthentheresphysics.wordpress.com/2015/12/17/rcps-as-scenarios/

    Our emphasis.

    I therefore conclude that the two memes come by way of the Editor, and declare beer-o-clock:

  134. paulski0 says:

    Willard,

    You can take it back to early 2014 at Judy’s. The Editor was there. This is also Ridley’s reference for dismissing RCP8.5 in his November 2014 article. Though, as noted earlier, Ridley seems not to have read much beyond ‘RCP8.5 bad’ because the article and the author goes against Ridley’s entire world view. Rutledge literally believes collapse of fossil fuel driven growth is possibly just a few years away due to lack of supply, arguing that without any mitigation efforts at all the scenario we follow will likely be between RCP2.6 and RCP4.5. Which would require dramatic emissions reduction starting pretty much now.

  135. Willard says:

    Thanks for the pointers, PaulS, and for making me read back Bart R’s comments, e.g.:

    Wow. That’s some oversight by the IPCC, if true. Burning more than the world’s reserves of coal in so short a time seems something patently within the sort of bounds checking and estimation practice a review committee would practice.

    Did you trace the origins of the errors?

    https://judithcurry.com/2014/04/22/coal-and-the-ipcc/#comment-530136

    In his non-response to BartR, Ian refers to Euan’s, another link in the Contrarian Matrix which would deserve due diligence. Meanwhile, the post ends with a link to a previous post by Ian, vintage 2012-05-03. A gem-like fall:

    How do these emissions compare with the IPCC numbers? The forthcoming 5th Assessment Report uses representative concentration pathways, RCPs for short. The total carbon-dioxide emissions here, 857GtC, fall between RCP2.6 (peaking around 660GtC in 2070) and RCP4 (1,100GtC and rising in 2100). However, these RCPs assume an effective climate policy. They start with a prescribed top-of-atmosphere forcing and work backwards to a published scenario. It would be more appropriate to compare the emissions here to RCP8.5. This is the only RCP that is unconstrained by climate policy and it might be said, even by geology, with cumulative emissions of 5600GtC in 2500.

    For people in the renewables business, what are the implications of a 60-year time frame for reaching 90% of the eventual long-term production? I do not know, but I will guess. You will be facing economic headwinds for decades, and competing with rent seekers who are better at securing favorable rules than they are at actually producing energy. You will be dependent on subsidies and renewables targets, in other words, on other people’s money. But as the Iron Lady observed, other people’s money runs out.

    https://judithcurry.com/2012/05/03/energy-supplies-and-climate-policy-2/

    The “Iron Lady” in question, for all of you Millenials, is Margaret Thatcher. Considering the scale of fossil fuel subsidies up to these days, we may take her factual claim with a grain of salt.

    In any event, it’s safe to say that [The Editor] has done a great job documenting how RCP 8.5 &c. has been substantiated.

    ***

    Incidentally, another Paul, PaulP or Web, often drives by at AT’s. He used to hang at the Oil Drum, and I think is long on peak oil. And when PaulW steps foot on the ClimateBall field, you know it’s serious:

  136. Leto says:

    RPJ says: “Just as doctors don’t spend a lot of time with healthy people, policy scholars don’t spend a lot of time on policies that are working.”

    Funny you should bring that up. When a doctor administers a painful vaccine jab to a healthy patient, and the patient says “Why is this necessary”, the doctor explains the disease being prevented. You’re like the patient who says, “Don’t waste my time discussing unlikely 1% outcomes, this scare-mongering disease-porn, just tell me why I need this painful jab?”

  137. Willard says:

    On January 2016, between the 5th and the 7th, there was an exchange at the Auditor’s involving HAS and the Editor (edited for conviviality):

    [Andre] Since climate talks usually take rcp85 as business as usual, maybe an explicit comparison for that would be interesting?

    [HAS] RCP8.5 isn’t business as usual. It is an upper bound on the IPCC AR5 scenarios, in general reflecting the 75% upper limit of the scenario drivers. In IPCC-speak I guess that makes it unlikely.

    [Doc] It is the 50% marker as Business worse than usual which makes up the other 50% is not modeled [I thought]. Consequently any average of models is already missing 50% of predictions on the high side as they were never made.

    [HAS] Not business as usual.

    [Editor] Andy makes an important point. RCP45 assumes mitigation measures beyond anything visible today. RCP85 is the scenario behind almost every extreme climate forecast, used because of the fallacious labeling of it as the “business as usual” scenario. Why did you choose RCP45 for this comparison?

    [Auditor] I used RCP for the comparison when I did it previously a couple of years ago. For the period in question, there isn’t much difference between the two and it wouldnt impact the appearance of the graph. Plus I’ve been very sick and, since I had one consistent set of model runs, had zero interest in verifying another set.

    https://climateaudit.org/2016/01/05/update-of-model-observation-comparisons/#comment-765678

    Doc is our own Doc. Good ol’ Doc.

    Here would be HAS’ rationale:

    Riahi et al “RCP 8.5—A scenario of comparatively high greenhouse gas emissions” Climate Change (2011) describes it as “the upper bound of the RCPs” and “a relatively conservative business as usual case”. It is the latter reference that saw BAU get incorrectly applied to it.

    Riahi et al further states “With few exceptions …. RCP8.5 builds … upon the socio-economic and demographic background, resource assumptions and technological base of the A2r scenario.” This A2r scenario is described in Riahi et al “Scenarios of long-term socio-economic and environmental development under climate stabilization” (2007) as aiming “to be positioned above .. the 75th … percentile … of the comparable scenario literature, but without all their salient scenario parameters necessarily always falling within this indicative range.”

    Basically treat RCP8.5 middle projections as the upper bound of the likely scenarios.

    So it’s unlikely because it’s bigger than the other RCPs.

    Still not sure where that “<1%" comes from, however.

    HAS' misreading of "conservative" has been addressed in the previous thread, right before he stopped responding to my comments.

    Probly because I make no sense whatsoever.

  138. Steven,
    I think at least 3 different people have highlighted that paper; are there any others? The obvious issue I can find is that if it really is that constrained (i.e., can’t exceed 610 ppm), then that would suggest that we can’t emit any more than about another 600GtC. That would seem to suggest that we should be rapidly thinking about developing alternatives. Also, if I understand the logic in the paper, we shouldn’t bother with CCS because actually extracting fossil fuels will be constrained, so we need to actually use alternatives to fossil fuels (not simply coal with CCS) and need them soon.

  139. verytallguy says:

    AT,

    indeed, there is a catch -22 for advocates of continued unconstrained fossil fuel usage:

    If they are scarce then a resource crunch is imminent, so we need to transition urgently.

    If they are abundant, we’ll fry, so we need to transition urgently.

  140. Hyperactive Hydrologist says:

    There is a significant resource of methane hydrates if we decided to develop the technology to extract it.

  141. Even though Roger might have left, I did think it good that he commented here. Partly, more dialogue is good, and partly it gets boring if people don’t engage.

  142. Dave_Geologist says:

    Sometimes the oldies are the best. Timewarp back to the pre-RCP SRS’s and we can pick one (A1B) that lies between RCP6.0 and RCP 8.5. So maybe where we’ll end up, assuming Trump, Ridley et al. don’t get their way, but Paris moves slower than hoped for because of foot-dragging, burden-shifting and technology delays.

    When can we expect extremely high surface temperatures? uses A1B to model temperature extremes (T100 values, maximum summer temperature on a 100-year return basis).

    In much of the US, in southern Europe and in the populated regions of Australia values far exceeding 40°C are reached. Such temperatures, if lasting for some days, are life threatening and receive relatively little attention in the climate change debate.

    For example, projected T100 values far exceed 40°C in Southern Europe and the US Midwest by 2090 – 2100 and even reach 50°C in north-eastern India and most of Australia. Such levels receive much too little attention in the current climate change discussion, given the potentially large implications.

    Yes it might only be once per century, but I expect that parts of large countries or regions will be hit more often. Maybe Texas one year, Kansas a decade later. Spain one year, Greece 20 years later. And of course the T80, T60 etc. temperatures will be no picnic.

    I could of course have led with this paper An adaptability limit to climate change due to heat stress, but didn’t want to be accused of peddling climate porn. In case some broker or auditor thinks that it is, I’ll quote the disclaimer which shows they are not claiming it as a likely outcome:

    Such worst-case scenarios (along with possible surprise impacts) may be an important or even dominant factor in evaluating the risk of carbon emissions, analogous to situations in which people buy insurance

    Since it’s in the second paragraph, a lazy analyst who only reads the title and abstract might miss it.

    We conclude that a global-mean warming of roughly 7 °C would create small zones where metabolic heat dissipation would for the first time become impossible, calling into question their suitability for human habitation. A warming of 11–12 °C would expand these zones to
    encompass most of today’s human population. This likely overestimates what could practically be tolerated: Our limit applies to a person out of the sun, in gale-force winds, doused with water, wearing no clothing, and not working. A global-mean warming of only 3–4 °C would in some locations halve the margin of safety (difference between T W max and 35 °C) that now leaves room for additional burdens or limitations to cooling. Considering the impacts of heat stress that occur already, this would certainly be unpleasant and costly if not debilitating.

    The point of analyses like this, which the Rogers of this world apparently fail to grasp, is that when it comes to catastrophic-by-any-measure impacts (disruption on the upper end would make billions of people refugees and inevitably bring on WWIII), we should not be thinking in terms of most-likely scenarios, but low-probability/high-impact scenarios. For example, testing any RCP against a 6°C ECS, at the upper end of the palaeo estimates. Yes it’s unlikely, but far from impossible and it would literally mean the end of civilisation as we know it.

    That harks back to my comment some time ago about the PETM. We really, really shouldn’t go there (7-8°C warming). Not ever, not just not-by-2100. “Very unlikely” isn’t good enough. I suspect even these papers underestimate the high-end impact. Across the world, the rock record shows that the hydrological cycle changed drastically during the PETM. Seasonal climates much like today’s changed to decades-long megadroughts broken by megafloods which rolled car-sized boulders hundreds of miles. The models don’t seem to predict that (I’m aware that PETM models with the right continental configuration also struggle). Extreme value analysis doesn’t break out the ultra-high temperatures as a secondary mode, just as a fat tail. Which suggests that there was some sort of tipping point into the PETM we can’t model. The transition into the PETM was so fast that geology can’t constrain where in the 3-4°C to 7-8°C range the tipping point lay. Maybe the current world is a lucky one with no tipping point or one at higher temperatures. As Dirty Harry would say: you’ve gotta ask yourself one question: “Do I feel lucky?”

  143. Dave_Geologist says:

    Couple of obvious points on Wang et al:

    1) Peak oil projections have been around for decades so we can assess their track record. Which is? They all got it wrong. New geography, new technology, cost reductions, price rises. Reserves are a bare minimum number. They have to be economically producible under current price and tax regimes, are time-limited if they’re tied to a fixed-term licence-to-operate or production-sharing-contract (and gas to a dedicated customer only counts until the end of the contract or the maximum agreed purchase volume, whichever is the lesser), and only get into the top category once you’ve allocated the development capital. One thing you can be sure of is that some (but not all) of the resources will be moved into reserves in the future. And new stuff will be moved into resources as it’s discovered or technology advances. Plus everyone took a reserves write-down when the oil price fell in 2014. It’s still in the ground, and in many cases the infrastructure is still there or the construction plans are on the shelf, so it can be reactivated if the price goes back to $100.

    2) Recent production forecasts will have made assumptions not only about population and economic growth, but about prices, carbon taxes, pricing-out by shale gas, solar or wind, etc. So you have to exclude forecasts that assume an IPCC world. Did they? Otherwise it becomes like the ozone hole (it stopped growing, there was no need to clean up our fridges after all) or the millennium bug (nothing bad happened, so there was no need to put all that effort into ensuring nothing bad happens).

  144. Steven Mosher says:

    attp.

    looks like they did a meta analysis of other literature. im sufficiently suspicious of peakerism…that said perhaps it will generate more interest in supply side approaches…my sense is the transitioning is happening…and there is no going back. Just my gut and what i see day to day. anecdotal of course.

  145. Willard: “On January 2016, between the 5th and the 7th, there was an exchange at the Auditor’s involving HAS and the Editor (edited for conviviality):
    [Andre] Since climate talks usually take rcp85 as business as usual, maybe an explicit comparison for that would be interesting?

    That is an unfortunate start of that discussion. The climate talks are not about business as usual. It would be more reasonable to say that the (Paris) climate is focussed on scenarios between 1.5°C and 2.0°C warming. Talking about scenarios which are unrealistic without clear political changes: a return to democratic, free and open societies.

    Without a climate intervention 1.5°C seems less realistic to me than RCP8.5. Still we need to know what happens in the best and the worst case. That makes it possible to make societal/political decisions. Only computing a realistic scenario would not be informative, would not tell us what the influence of human activities are.

  146. Steven,

    my sense is the transitioning is happening…and there is no going back.

    I agree. I suspect that it will end up be easier than suggested by some, but more difficult than suggested by others (which, admittedly, doesn’t really may say much).

  147. Chubbs says:

    To provide better context the RCP/SSPs could be tagged with the paleo climate they come closest to. Then imprecise and controversial terms like BAU could be dispensed with. Looks like we have the past 400 million years covered. Note this chart has a Wink20k scenario which burns all fossil fuel resources.

    https://www.nature.com/articles/ncomms14845/figures/4

  148. Everett F Sargent says:

    ATTP,

    “I think at least 3 different people have highlighted that paper; are there any others? The obvious issue I can find is that if it really is that constrained (i.e., can’t exceed 610 ppm), then that would suggest that we can’t emit any more than about another 600GtC.”

    All those energy papers are based off of PROVEN RESERVES. All such papers show peak oil/gas/coal before the end of the 21st century.

    There is another category called ENERGY RESOURCES (in other words, given what we have already found/use/will use globally, where else might we find additional fossil fuel resources that are economically recoverable with today’s technologies, in other words we have a l-o-o-o-o-o-g way to go before we dig up the entire Earth).

    I have found BGR to be the best of the various annual outlook reports ,,, e. g. for 2017 …
    https://www.bgr.bund.de/EN/Themen/Energie/energie_node_en.html

    BGR,Reserves (EJ),Resourcea (EJ),Production (EJ),Reserve Production (years,Resource Production (years
    1997,35126,324561,,,
    2001,35477,194051,334,106,581
    2004,37492,182350,,,
    2005,38590,201116,405,95,497
    2006,39570,341543,434,91,787
    2007,39105,504161,440,89,1147
    2008,38695,571711,439,88,1302
    2009,38946,571368,453,86,1261
    2010,39794,575180,457,87,1260
    2011,39375,516939,479,82,1079
    2012,39459,520118,494,80,1053
    2013,39910,521521,509,78,1026
    2014,37646,537840,515,73,1045
    2015,37934,551813,522,73,1057
    2016,38443,540371,521,74,1037
    2017,39530,542786,515,77,1054
    2017,3298 Gt CO2,49803 Gt CO2,,,
    2017,900 GtC,13,600 GtC,,,

    I would need to break these out for oil/gag/coal but very roughly 100-200 years of oil/gas ~3,000 years of hard coal and ~1,000 years of soft coal (lignite) based on 2017 energy production (or consumption as it is ~equal to production) rates (from memory, as I did the full oil/gas/coal calculation almost a decade ago).

  149. > All those energy papers are based off of PROVEN RESERVES.

    This was Paul S’ conclusion when reviewing the 2014-11’s op-ed:

    Rutledge’s guest post at Curry’s was Ridley’s source. It’s a small world after all.

    Rutledge’s analysis is entirely in line with many other projections: if we consider only conventional reserves of fossil fuels, production will peak in the 2030s. The important question, which Rutledge doesn’t address at all, is how far unconventional recovery and production techniques will allow us to tap into the much greater known resources, which currently are not counted as reserves?

    https://andthentheresphysics.wordpress.com/2014/11/05/come-on-matt-ridley-its-not-that-difficult/#comment-36696

    Seems that we’re already into tar sands. I don’t know if we started exploiting oil shale yet.

    RobertW expected that LC14 would be amended with increased estimates. It doesn’t seem that this is what happened. I wonder why.

    ***

    I also found back a post on Nic’s submission to the Parliament:

    If TCR really is 1.35°C then under RCP8.5 – the worst-case, business-as-usual scenario – the end of the 21st century will be approximately 2°C warmer than today.

    The meta-analysis in Tol (2009)22, of fourteen estimates from economists, suggests that a temperature of 2°C warmer than today is likely to have a negligible impact on welfare.

    https://andthentheresphysics.wordpress.com/2013/12/20/nic-lewiss-submission-to-the-uk-government/

    And then there’s Gremlins.

  150. Eli Rabett says:

    Ah yes, Sherwood and Huber, from the comments back when people were not wasting their time here but doing good work at Rabett Run

    http://rabett.blogspot.com/2010/06/death-doom-and-disaster-coming-soon-to.html

    It’s the creeping statistical hints between the lines of this paper that really bother me. Long before or even if we never see broad areas permanently enter a existentially threatening torrid regime, what about excursions? For instance, Pakistan this year has seen record temperatures approaching 54 degrees C in places where many people live, fortunately with lower humidity and only for handful of days but what about when/if such aberrations extend to a handful of weeks and are accompanied by inexorably increasing humidity? The resulting disaster would cause migrations. The worst-case scenario in Sherwood and Huber would not have to happen before we effectively lose major swathes of territory for year-round habitability.

    We’ve lost a couple of decades to well funded denial

  151. From Eli’s lair:

    I happen to think the RCP8.5 case can´t be acvhieved at all, and it doesn´t represent a “business as usual” case at all.

    A shorter version of it is “RCP 8.5. is a joke,” which I’ve heard here and there.

    ***

    A 2011 hit at Judy’s:

    Tim Worstall has a post at Forbes entitled “Solving Climate Change.” Worstall argues ironically that the solution to the climate change problem lies within the assumptions made in developing the RCP scenarios.

    https://judithcurry.com/2011/08/11/representative-concentration-pathways/

    Tim argues ironically a lot. Judy also refers to a previous post, which bears an intriguing name and contains this gem:

    At the heart of Betz’s argument regarding IPCC scenarios violating the precautionary principle is the concept of modal logic.

    https://judithcurry.com/2010/10/12/do-ipccs-emission-scenarios-fail-to-comply-with-the-precautionary-principle/

    Then we got served some possibility theory.

    In the comments, Richie suggests that Judy’s “faith” in the scenario is misplaced because, aliens. The post only attracted a few comments.

  152. Tim Worstall’s article is interesting

    Or, to boil it right down, the IPCC is telling us that the solution to climate change is economic growth and low-carbon energy generation.

    Simple.

  153. Alas, AT, Tim is wrong:

    Tim Worstall is wrong to compare the RCP scenarios. They were drawn using different models. Any comparison is thus inconsistent.

    https://judithcurry.com/2011/08/11/representative-concentration-pathways/#comment-97300

    But Richie doesn’t blame Tim – Van Vuuren et al. encourage silly inferences.

    It’s all Van Vuuren’s fault.

  154. Well, yes, I’m not surprised that he’s wrong to use the RCPs in the way that he has. However, he probably is right about low-carbon energy generation being part of the solution, but this is not exactly a surprise.

  155. I suspect that what Richard is pointing out is that the RCPs essentially came first and then they generated various socio-economic pathways that *could* lead to those RCPs. However, they’re not really a consistent/coherent set of pathways and they may not be unique (i.e., trying to match the socio-economic conditions associated with a particular RCP does not guarantee that one would then generate that concentation pathway).

  156. The rest of Richie’s comment may indicate one possible source for the “<1%" meme:

    Judith is right. There are plenty of observations on population, economic activity, energy use, and emissions. These data can be used to validate models and assign relative probabilities to the scenarios. In fact, this has been done. Google Books “Economic Scenarios for Global Change”. The application is to the SRES scenarios, but the same models were used for the RCPs.

    The IPCC cannot claim not to know this, as shown here:

    http://www.ipcc.ch/pdf/supporting-material/expert-meeting-2005-01.pdf

    That comment thread contains what could be the first comment by RichardB at Judy’s, which ends with the perennial:

    So it’s very important that the climate model simulations driven by the RCPs are *not* regarded as predictions – just scenarios.

    https://judithcurry.com/2011/08/11/representative-concentration-pathways/#comment-97312

    It echoes Pekka’s comment on the difficulty for many to understand RCPs.

  157. Mitch says:

    First, RCP’s were developed in order that different GCM’s could run with the same forcing, including aerosol and minor GHG emissions. So, they were only intended to be a scenario that looked something like the real world and would lead to the forcing desired. So it is complete climateball to start criticizing the scenarios as being unrealistic. They were always cartoons–look at RCP2.6 and its implied CCS to get to its goal.

    Second, there actually has been at least a dribble of literature about unrealistic coal production levels in the IPCC scenarios (see Patzek and Croft, Energy 35 (2010) 3109-122 for example). The good news appears to be that the economics have shifted sufficiently that coal extraction is becoming financially risky. The economic shift would be faster if fossil fuel industries were not so aggressively blocking change.

  158. Ragnaar says:

    I see aspects of trying to break the climate with RCP 8.5. It’s fun. I don’t know why people like to watch videos of things breaking?

  159. paulski0 says:

    Willard,

    Tol’s conclusion in the transcript in that pdf is that ‘The SRES scenarios are not equally likely; A2 is by far the most probable’

    A2 is also by the far the most similar to CMIP5 RCP8.5.

  160. Steven Mosher says:

    Burn it all, I’m going fishing.

  161. paulski0 says:

    Mitch,

    Patzek and Croft is part of the array of supply-side literature discussed above, and a look at their prediction is illustrative of the general problem with that literature. Their model produces peak coal production in 2011, and suggests by now it should have declined by about 10%. That’s not at all the case.

  162. Before the end of the century, global demand for energy will lie somewhere between 150 million and 300 mbtus annual per capita. Any gap between this demand and what is delivered will correctly be identified as a proxy for poverty.

    Choosing the fuel portfolio that will provide this energy is where we have room to play regarding climate change. If it is green fuel we will be happier than if it is dirty. China has already realized this, as has the US and Europe.

    Both the ARs and RCPs are unwitting hostages to assumptions about sensitivity of the atmosphere to a doubling of concentrations of CO2. Looking at fuel portfolios is a much simpler way of calculating what we can and should do. At least the math is simpler.

    Pielke’s calculations in my mind better describe our present and possible futures than either ARs or RCPs. They highlight areas of concern as well as potential solutions.

    Solar power has shown the ability to scale. If battery storage increases in efficiency, it need only grow by half its historic rate to arrive at adequate energy for the planet. We can get significant contributions from hydro, nuclear, wind and geothermal in localities where that makes sense, or for purposes where, for example, nuclear is a better option for rail transport than solar.

    Fossil fuels will probably always figure in to air transport calculations. Other than that, continuing with established 50-year trend lines should provide us all with optimism.

    So my question is why not use Pielke? Why is he your enemy?

  163. PaulS,

    Session 7 is interesting. I tend to agree with this:

    Marty Hoffert, New York University, presented on the disadvantages of probabilistic approaches. He showed the huge uncertainty in the SRES and other scenarios. He also showed the outcome of a study published in Sciencefrom Caldeira et al. on the uncertainty in climate sensitivity. His main point was that it is better to approach the problem from the other end: how can we provide all that energy without CO2 emissions to meet different climate objectives, given different assumptions about climate sensitivities? Hoffert stated that without assumptions on significant new sources of carbon free fuels, low emissions scenarios cannot occur in the future. The bottom line would be that we will need 10TW emissions-free energy by 2050 according to a (IS92e) BAU scenario and 8TWadditional emissions-free energy to reach 500 ppm from IS92e BAU. Therefore, much more bottom-up technological information is needed in the scenarios

    The overall discussion is also interesting. It shows that Richie cannot claim not to know that assigning probabilities to scenarios is problematic:

    The discussion focused on the use of probabilistic scenarios and some methodological issues. The data but also the methods used by Tol were seriously criticised amongst others because they are based on the assumption that historic conditions do apply in the future. Tol did explain that he is aware of the simplicity of his method and admitted that the method is not mature enough to evaluate the SRES probability.

    There was a request for more clarification on the complementary of the storyline and the probabilistic approach suggested by Webster. It was explained that after selecting a storyline, probabilistic approaches can help inform the quantification of that storyline by taking information from probabilistic analysis to provide parameter values. However, storylines, that still are the main way to address emissions scenarios contain certainly more elements than scenarios themselves, and contain information than cannot necessarily be modelled. Probability assessment across storylines might not be correct. However, this issue requires further discussion.

    An important other aspect discussed was policy intervention in scenarios. In theory it is preferred to have a distinction between policy intervention and baseline assumption. This is difficult to establish and even more for future analysis. In probabilistic approaches this means that policy choices should also be described in terms of probability but that is very difficult.

    http://www.ipcc.ch/pdf/supporting-material/expert-meeting-2005-01.pdf

    If we could ever assign probabilities to policy choices, but I’m sure Palantir or Cambridge Analytica clones would like to hear about that.

  164. > [Junior]’s calculations

    That would be a good idea.

  165. Eli Rabett says:

    Hoffert is the BTI guy who was pushing solar satellites that provided energy to the ground via lasers. He was very pissed that funding was declined. Any sentence that contains Hoffert and realistic or reasonable is subject to inquiry.

  166. Everett F Sargent says:

    “That would be a good idea.”

    Junior has his own SSP? I’m all ears.

    Because the Kaya Identity is a joke you play in HS algebra class.

    F(x) = y* (a/b * b/c * c/d * d/e * e/f * … m/n * n/o … * x/y * y/z * z/a) = y
    https://en.wikipedia.org/wiki/Kaya_identity#Critique
    “The Kaya identity and its applications in climate control policies has been criticized by Mario Bunge.[8] Bunge points out that the Kaya identity is a tautology, because it is nothing but a rewrite of the identity : F=F, i.e., “Carbon is carbon”. Bunge concludes that the Kaya identity is impervious to empirical data, i.e., the Kaya identity cannot be tested empirically and thus cannot be used for predictions. In addition, Bunge proposes a tentative formula for the volume of global carbon emission that is not just a simple identity. Bunge suggests means to control climate and finally states “it might also help if economics students were to take Logic 101”.

    It’s utility function is exactly equal to zero (e. g. assume a bunch of CONSTANTS as ratios of CONSTANTS put all said CONSTANTS in the numerators AND denominators) because it all CANCELS out.

  167. Willard says:

    > Any sentence that contains Hoffert and realistic or reasonable is subject to inquiry.

    Thanks, Eli. I should have checked. While we may suspect some bias behind these citations, Hoffert seemed to defer to Caldeira’s work and some IS92e BAU scenario. Searching for “IS92e” I found this description:

    The IS92 scenarios span a range for global average economic growth from 1.6 to 2.5 Percent – the SA90 high and low growth scenario assumed 1.1 and 3 Percent (Pepper et al. 1992:13). In addition, the IS92 does not use the mean of the high and low growth projections. This widening of the economic growth rate projections is the main cause for the increased range of the emissions level of the IS92 scenarios. Like in the SA90 scenarios, the GNP growth is assumed to slow down towards the end of the 21st century because of the expected slowing of population growth. (Pepper et al. 1992:11)

    Because there are no carbon fees or other climate policy assumed, the reduction of the energy intensity and carbon content is lower in the IS92 scenarios and has a smaller range than the SA90 scenarios series. Even though, the “share of different primary energy supplies change dramatically in all of the scenarios due to assumed limitation in fossil resources, expected advances in energy technologies, as well as calculated increase in energy prices” (IPCC 1992:84). The two central IS92 scenarios (IS92a, IS92b) assume conventional oil and gas production to be gradually replaced by unconventional fossil resources, by synthetic fuels from coal, and non-fossil energy supplies, leading to a to a non-fossil primary energy supply of 43% by 2100 (IPCC 1992:84). In the IS92 scenarios a tendency towards more optimistic and more pessimistic3 scenarios can be observed, since high economic growth is coupled with high availability of conventional oil and gas resources as well as phase out of nuclear, slower decrease or even increase of the costs of renewable or nuclear energy (IS92e, IS92f). On the other side the scenario with low economic growth assume low conventional oil and gas resources, as well as higher decline in the costs for renewable and nuclear energy (IPCC 1992:84).

    Setting 18TW as the objective is less melodramatic than to proclaim that we’ll need 3000 quads by 2075, and if they all come from coal we’re ruined, don’t you think?

    Nevertheless, getting to 43% non-fossil does not seem to be a walk in the park either.

  168. Mr. Sargent, hence the word ‘identity.’

  169. Dave_Geologist says:

    Willard

    In the comments, Richie suggests that Judy’s “faith” in the scenario is misplaced because, aliens. The post only attracted a few comments.

    I rarely go there but followed the link this time. A couple of posts down:

    curryja | October 14, 2010 at 9:27 am |
    Tom, I am saying that the highest scenario might not be high enough.

    Wow! Am I reading that right? RCP8.5 doesn’t go high enough? Helluvan incentive to become a luckwarmer!

  170. Dave_Geologist says:

    I see aspects of trying to break the climate with RCP 8.5. It’s fun. I don’t know why people like to watch videos of things breaking?

    It’s not fun Ragnaar. It’s an appropriate level of caution. We test cars, seatbelts and airbags in crashes even though we don’t expect any particular car to crash. We test (or calculate) the load limit of bridges so we know what we can stay safely below. Because dozens of cars falling into a river and a billion dollar investment reduced to rubble is a Bad Thing. RCP8.5 is a Bad Thing. With ECS of 4.5°C it’s a Very Bad Thing. With the upper palaeo ECS of 6°C it’s a Very, Very Bad Thing. With the upper nonpalaeo limit of 10-20°C, depending on where you cut of the tail, RCP8,5 would take the Earth to conditions not seen since the Late Heavy Bombardment. That’s no longer a Thing, because only thermophilic archaea and bacteria will be left and they never got round to the Thing thing.

    So we evaluate RCP8.5 as a guide to what not to do.

  171. Dave_Geologist says:

    Mitch, Patzek & Croft suffers from the same limitation i mentioned before. Hubbert curves are an analysis of what is already known and in production. The latter depends on economic factors and investors’ guesses about future policy. Even if the CoalCo is determined to soldier on, investors will desert it, the share price will collapse and it won’t be able to raise working capital. As has indeed happened. Utility investors who foresee a future where coal-fired plants will be directly (regulation such as scrubbers or CCS or offsets such as reforestation) or indirectly (carbon taxes, consumer resistance) impacted by a world which listens to the IPCC will not invest. The market for coal will dry up and it will become uneconomic to mine. The coal will still be there though. If utility investors foresee a Burn-Baby-Burn future they will invest, the coal price will be supported, and existing and new resources will be extracted. Fortunately, they and the miners work on multi-decade investment cycles, so they need to take a long-term view of global attitudes, and not just one President. So I don’t expect to see Trump shifting any Hubbert curves soon. Maybe if he gets re-elected and/or appoints enough conservative Supreme Court judges to ensure future attempts at regulation are litigated into the ground.

    Britain (minus Matt Ridley) didn’t stop producing coal because it ran out. We stopped because it couldn’t compete with imports from the other side of the world. The shut-in Appalachian mines which produced at $130/ton aren’t shut in because the local coal-fired power station shut down. It’s burning Utah coal which costs $40/ton even after shipment. Although views on how long the coal-fired stations will carry on, and what price they’ll be able to pay after tax and cleanup costs, no doubt influenced decisions on whether to modernise the mine to reduce operating costs or to write it off and invest in gas.

    Investor and management assumptions are therefore baked into the existing Hubbert curves. And into any the authors generate for undeveloped resources. Production did fall in 2011, but that was almost entirely driven by political decisions in China. What if Chinese growth falls to 2-3% long-term and oil prices soar again, when they still have half a billion on low incomes? A regime worried about stability might decide to go back to coal and install scrubbers to reduce complaints from the neighbours. Which of course will mean less of their CO2 is offset by aerosols.

    It’s ironic that the paper claims to be introducing much-needed-geophysics into the debate. As someone who spent a large chunk of his career practising geophysics, I have to say I don’t see one iota of geophysics in the paper. Just numerology. A geophysical (and geological approach) is to estimate how many acre-feet are producible using current and foreseeable technology. Then triage that by production costs and assumptions about future prices and regulation. I’ll bet someone’s done that already. And I’ll bet they came up with a larger number.

  172. Dave_Geologist says:

    Seems that we’re already into tar sands. I don’t know if we started exploiting oil shale yet.

    Oil shale is old-school Willard.

    It was a bit of a niche. I believe the Romans mined or quarried the Kimmeridge Clay in southern England, alerted by the observation of cliffs burning after a lightning strike. Scotland and presumably Estonia had the right conditions for early development (at least in the case of Scotland, the right rocks at the right depth with local industrial expertise and a ready market). It was too expensive for fuel though, and was used to make lighting oil and petrochemicals. Estonia seems to be able to mine and retort it competitively with oil and coal. According to the British Geological Survey the Scottish ones are oil-mature to about 2300 feet and gas-mature at greater depths. It would be difficult to frac the oil-mature ones without risking groundwater contamination, due to the shallow depth and to the fact that they’re riddled with old mine workings. Ineos wants to frac the deeper ones for gas.

    The oilier unconventional resources in the USA are essentially oil shales. So 50% of US oil production is oil shale, produced by drilling and fracking rather than mining. Which is probably the least environmentally unfriendly way to do it, but excludes thermally immature resources.

    A century old and it’s still not vegetated.

  173. Dave_Geologist says:

    Looks like WordPress won’t display the png, but you can click through the placeholder (to Wiki).

  174. Dave_Geologist says:

    thomaswfuller2

    Both the ARs and RCPs are unwitting hostages to assumptions about sensitivity of the atmosphere to a doubling of concentrations of CO2.

    If you mean CO2 sensitivity is baked in, you’re wrong. The emissions paths drive models, each of which has its own climate sensitivity. But you knew that because it was pointed out several times upthread, and you wouldn’t jump in without reading what went before.

    There are no assumptions about sensitive outside Denierville. There are calculations based on scientific measurements. The only assumptions are that the laws of physics apply.

  175. The Very Reverend Jebediah Hypotenuse says:


    RCP8.5 is a Bad Thing. With ECS of 4.5°C it’s a Very Bad Thing. With the upper palaeo ECS of 6°C it’s a Very, Very Bad Thing. With the upper nonpalaeo limit of 10-20°C, depending on where you cut of the tail, RCP8,5 would take the Earth to conditions not seen since the Late Heavy Bombardment. That’s no longer a Thing, because only thermophilic archaea and bacteria will be left and they never got round to the Thing thing.

    But – Her e-mails….

  176. Dave said:

    “Mitch, Patzek & Croft suffers from the same limitation i mentioned before. Hubbert curves are an analysis of what is already known and in production. “

    Right. A Hubbert logistic curve is only a heuristic that has no theoretical underpinning. The hack that usually goes into the logistic formulation is the differential equation dP/dt = kP(1-cP) where P is cumulative production. There are much better mathematical treatments than this, subject to the vagaries of economic activity.

  177. Mitch says:

    Dave_Geologist, to your point “…The shut-in Appalachian mines which produced at $130/ton aren’t shut in because the local coal-fired power station shut down. It’s burning Utah coal which costs $40/ton even after shipment. The shut-in Appalachian mines which produced at $130/ton aren’t shut in because the local coal-fired power station shut down. It’s burning Utah coal which costs $40/ton even after shipment…”

    And, burning Utah/Wyoming coal was established because they were low sulfur despite being low-BTU, so were economically viable only after a cap and trade was placed to limit acid rain. The point is that economics will limit fossil fuel use, including finding ways to include externalities. China will probably not go back to coal because the pollution externality is one of the major driving factors they had to move to other forms of power. Why use coal when it can be done better at a cheaper cost in an alternative fashion?

  178. Ragnaar says:

    Dave_Geologist:

    Utah has cheap coal. Meaning the deal is to stop coal trains from moving West to East as was the goal in Rochester Minnesota. It was a complicated situation but the stoppers won, exact reasons being subjective. That there is little coal moving by rail through Rochester means there’s a greater chance Appalachian mines will not close.

    Protesting fuel transportation is a mixed bag at best. Perhaps it’s the only way to make people take public transportation. The real fuel to protest is whatever jet airliners burn.

  179. Steven Mosher says:

    “So we evaluate RCP8.5 as a guide to what not to do.”

    yup. we already know what 8.5 teaches us by looking at 6 or 4.5.

    1. 8.5 or some maximumalist is methodologically sound, to begin with
    2. As scarenario it serves to tell a bunch of scary stories– Note when telling the
    scary story, nobody mentions there is no way to assign a probabilty to it, by design.
    3. There are sound reasons to question the likelihood of RCP 8.5 being a reasonable
    vision of the future, and none of these reasons are science denial.

  180. Ragnaar says:

    If a study is done and sea level rise will be 2.3 inches per decade, or your local temperature is plus 1.5 C in 30 years, eyes glaze over. A climate break is much more helpful as a message to advance the goals.

    The attributes of the climate and average people contribute to the eye glazing. I don’t care about the above changes. A local town will have a city celebration. MADD will bring in a smashed car. This could happen to you. The local police may demonstrate a stun gun by stunning whichever officer gets that job.

    It’s not good if smart cars work. You need pedestrians being hit by them. Running into a garbage can isn’t going to do it.

  181. Economics doesn’t limit fossil-fuel use, but geology does. To get at whatever anthracite coal is left in the Appalachian mountains, they have resorted to blowing off the tops of mountains, aka mountain-top removal. Everyone by now should realize how insane this is. When the non-renewable resource dwindles down to nothing, not much you can do about it.

    Anthracite coal in Pennsylvania is probably the best example of a Hubbert curve depletion profile

  182. Steven Mosher says:
  183. Steven,
    We can also understand 6 and 4.5 by using 8.5.

  184. Steven,

    There are sound reasons to question the likelihood of RCP 8.5 being a reasonable
    vision of the future, and none of these reasons are science denial.

    Indeed, but the context is actually more to do with claims that using RCP8.5 reduces the credibility of climate science and is “bad science”. I don’t recall anyone claiming that questioning the likelihood of RCP8.5 is a form of science denial (would be odd, given that it is probably now unlikely, even if not actually impossible).

  185. Willard says:

    There are sound reasons to question the “<1%" and "RCP 8.5 is a joke" memes. There are sound reasons to question the "RCP 8.5 is by far the favorite" claim, and the CAGW meme it helps peddle. There are very good reasons to see how these memes operate in the Contrarian Matrix, just like there are very good reasons to go fishing while due diligence is being paid.

    ClimateBall is nothing short of being Very Reasonable.

  186. paulski0 says:

    Steven Mosher

    yup. we already know what 8.5 teaches us by looking at 6 or 4.5.

    That’s an assumption. And it’s checked by looking at and reporting on what 8.5 produces.

    2. As scarenario it serves to tell a bunch of scary stories– Note when telling the
    scary story, nobody mentions there is no way to assign a probabilty to it, by design.

    Not a precise relative probability compared to other pathways, but we do know that it’s far more likely than RCP50 or RCP0. When running various non-mitigation (aka business-as-usual) storylines in economic models, something close to RCP8.5 consistently emerges as a plausible pathway. Has done for decades now. It therefore seems difficult to reasonably argue against it being a plausible future given no climate policy.

    Also, the probability issue applies equally to all the other pathways. Why do you only bring it up in relation to RCP8.5? It seems like the premise of your argument is informed by propaganda which has sought to isolate RCP8.5 as somehow separate from the other pathways.

    3. There are sound reasons to question the likelihood of RCP 8.5 being a reasonable
    vision of the future, and none of these reasons are science denial.

    That’s clearly not true. Some are science denial. E.g. Ridley one week arguing that RCP8.5 shouldn’t be considered in terms of climate impacts, and the following week arguing for the same fossil-fuel-rich future which RCP8.5 describes.

    There are potentially sound reasons to question plausibility, as is the case for all the other pathways. But that’s a very strange way to represent what this thread has been about. It hasn’t been about certain people simply ‘questioning plausibility’. It’s about those people making blatantly false statements (e.g. ‘IPCC said it has <1% probability', 'It's not a BaU scenario', 'IPCC dropped it in 2017') in an effort to discredit consideration of the consequences of this particular pathway, which they seem to find inconvenient. Pielke's tweet didn't suggest questions, it expressed absolute certainty: any use of this pathway should be condemned.

  187. paulski0 says:

    3. There are sound reasons to question the likelihood of RCP 8.5 being a reasonable
    vision of the future, and none of these reasons are science denial.

    That’s clearly not true. Some are science denial.

    Heh, missed the “No true Scotsman” form of this statement. Obviously none of the sound reasons are unsound.

  188. Willard says:

    > It seems like the premise of your argument is informed by propaganda which has sought to isolate RCP8.5 as somehow separate from the other pathways.

    We only need to recall that the propaganda in question echoes the luckwarm playbook to see that “informed” might very well be an understatement when attributed to our visiting dynamic duo.

  189. Ragnaar says:

    Fishing and due diligence. I think I’ve been triggered.

    “…there are very good reasons to go fishing…

    Why a Jig? The hook position reduces weed entanglement. Artificial baits on average are not swallowed by the fish which can damage the fish I assume severely. Artificial baits do not kill defenseless minnows and worms and one does not have to contemplate their demise at the fisher-person’s hands.

    In Minnesota, we have carp and eel pout fests. At least we used to have carp fests. We still have a catfish fest. Now with Lake Minnetonka tying the record for the latest ice out date going all the way back to before the Wright Brothers and potentially interfering with early fishing tournaments and the fishing opener, we’ve got things to do. Baby fish to stock. Run off ponds to build. Docks to put in and boats to launch. Trips to take and fishing reports to ponder.

    Due diligence is not casting into those trees overhanging the shore. Obeying the catch regulations. Checking the drag and tying a good knot.

  190. Willard says:

    You call that a jig, Ragnaar? That is a jig:

    Fernando Leanme has been all over the RCP 8.5 story. He’s commented on it here frequently but also at his own blog, a blog with a great masthead picture. Even if you don’t agree with Fernando or myself, it’s worth a look.

    https://thelukewarmersway.wordpress.com/2015/08/21/the-various-misuses-of-rcp-8-5/

    Commenting on the various misuses of RCP 8.5, like AT did in his post, doesn’t seem to infringe on any luckwarm catch regulation.

  191. Steven Mosher says:

    “Heh, missed the “No true Scotsman” form of this statement. Obviously none of the sound reasons are unsound.”

    hehe

  192. Steven Mosher says:

    ” I don’t recall anyone claiming that questioning the likelihood of RCP8.5 is a form of science denial (would be odd, given that it is probably now unlikely, even if not actually impossible).”

    You can look at it this way. one whole part of my effort to carve out a lukewarmer place was to point out issues ( like sensitivity and RCPs) where people who were skeptical could stand and argue
    without having to be in denial. Of fruitless I think now because whenever you point them at these places where they can make a good argument, they still butcher it.

  193. Dave_Geologist says:

    And, burning Utah/Wyoming coal was established because they were low sulfur despite being low-BTU, so were economically viable only after a cap and trade was placed to limit acid rain. The point is that economics will limit fossil fuel use, including finding ways to include externalities. China will probably not go back to coal because the pollution externality is one of the major driving factors they had to move to other forms of power. Why use coal when it can be done better at a cheaper cost in an alternative fashion?

    OK Mitch, but that still supports the point that perceptions of future regulatory environments impact Hubbert curves. What if Trump solves Korea and Iran, is praised as a hero and re-elected, and succeeded by a two-term Pence, with Pruit in charge of the EPA for a couple of decades. Acid rain can come back, or if sulphur scrubbers are subsidised, dirty coal can be burned (isn’t Clean Coal a Trump buzzword?)

    And China has mostly substituted oil and gas for coal, Renewables is only about 10%. Suppose the price of oil goes back up to $100, then doubles because western economies finally escape their post-2008 funk?

    Investors consider the future business environment for their investment, likely as well as unlikely outcomes. If perceptions change, Hubbert curves change (after a lag of course).

  194. Dave_Geologist says:

    yup. we already know what 8.5 teaches us by looking at 6 or 4.5

    No we don’t Stephen. Nonlinearities and signal to noise. But you know that because it’s been said multiple times already.

  195. Hyperactive Hydrologist says:

    I think if you are going to criticises the use of RCP8.5 for climate impact studies and claim the impacts are a significant exaggeration you have to demonstrate this and provide evidence. Feel free to correct me but I don’t see anyone who claims the RCP8.5 scenario is being misused has done this. Instead they attack the RCP8.5 scenario itself.

    As others have suggested, there is a large overlap between the RCP4.5, 6.0 and 8.5 scenarios. I would much rather scientists used all GCMs to asses impacts for the RCP 8.5 scenario than use 4 or 5 GCM for all RCP scenarios. Of course, In a ideal world you would do both but considering the effort it takes to assess climate impacts time has to be spent wisely.

  196. paulski0 says:

    China will probably not go back to coal because the pollution externality is one of the major driving factors they had to move to other forms of power.

    Figures for 2017 from China indicate a fairly big uptick in coal consumption, yet apparently still declining SO2 emissions. Maybe they finally turned the scrubbers on? This paper (not yet peer-reviewed) says stringent ultralow emission standards have been applied across all coal fired power plants and SO2 emissions are now down at under 50% of 2010 levels.

  197. BBD says:

    Steven

    Of fruitless I think now because whenever you point them at these places where they can make a good argument, they still butcher it.

    I see no good lukewarmer arguments, butchered or otherwise.

  198. izen says:

    So… using the RCP8.5 damages the credibility of climate science because it focuses on the worst case that may be unlikely.
    But using the lowest estimates of climate sensitivity (LC18?) enhances climate science.

    Because in assessing the risk from climate change, using the low risk estimates is acceptable in a way that high impact scenarios are not.
    An asymmetry that is politically imposed.

  199. Joshua says:

    Because in assessing the risk from climate change, using the low risk estimates is acceptable in a way that high impact scenarios are not.

    Let’s just make sure thst you make a distinction when you’re estimating the economic risk of mitigation. In that circumstance, high risk estimates should be the basis of policy development. Unintended consequences, doncha know.

  200. Eli Rabett says:

    RCP 4.5 or RCP6.0 still puts the luckwarmers between the rock and the hard place, it’s just that their grandkids get it in the neck rather than their kids.

  201. Steven Mosher says:

    BBD

    i know you cant see them. duh.

    question. do you undetstand the difference between a good argument….say nic lewis using accepted methods..and bad arguments….say monkton butchering the concept of feedbacks…

    do you get the difference between a good argument that you disagree with and a bad argument that is just wrong..OR are you just a moron?.

  202. Everett F Sargent says:

    I’m thinking that RCP8.5 does not have to happen by 2100. It is much easier to think of it happening in the 22nd century, more likely earlier 22nd century than mid-to-late 22nd century. Is this goalpost moving? Perhaps.

    That RCP8.5 happens sometime in the future is a real possibility though. For example, we miss the 1.5C and 2,0C targets this century. IMHO we will miss those targets with high probability, e. g. P>0.66.

    Given all the current emphasis on staying below either 1.5C or 2.0C and then missing those targets suggests something else will happen after the fact (e. g. exceeding 1.5C or 2.0C by say 2050, at least in terms of then current FF usage (e. g. a 2.0C future is guaranteed before 2100)). Humanity moves its own goalposts to 2.5C and then 3.0C and then 4.0C. In other words, significant FF usage continues throughout the 21st century and continues into the 22nd century.

    There becomes a point where we need to consider 2100 as just an arbitrary point in time. At some point in time, say 2050, 2150 becomes the new arbitrary point in time.

    The main difference between RCP1.9 and RCP8.5? We will know much sooner in time (before 2050 and most likely by 2030) if we meet RCP1.9 (as it is a lower asymptotic) then if we meet or exceed RCP 4.5 or RCP 6.0 or RCP 8.5.

    In fact, all this discussion of RCP 8.5 is a big waste of TIME, procrastination is the epitome of moving the goalposts and wasting TIME.

    We need to find the ones who have not given up, RPJr has most certainly given up (offers no meaningful solutions or meaningful pathways). To RPJr and his ilk I say, put up or shut up.

  203. Willard says:

    > do you get the difference between a good argument that you disagree with and a bad argument that is just wrong..OR are you just a moron?.

    I wouldn’t not put a false dilemma into the Good Arguments bin. I certainly would recognize “but Skydragons” as a common luckwarmer move. In fairness, this move leads to most interesting ClimateBall exchanges.

    Speaking of morons, VeeV pointed me to an exchange on ad hominems over the Tweeter. One of my tweets got Lee’s attention:

    Not all luckwarm arguments are good. Witness “RCP 8.5 <1%," "RCP 8.5 is not BAU" "RCP 8.5 is a joke." These are not made by the Monktopus. It makes sense to criticize them.

    In any event, my question is – why not use the IPCC? Why is it the luckwarm enemy?

  204. Everett F Sargent says:

    I, for one, don’t come here to make good or bad arguments. So, for example, I didn’t make the “RCP 8.5 is bogus” argument. Others did. However, we do need an upper limit scenario, so far, that upper limit scenario just happens to be something like RCP 8.5. In the future it might be something else (e. g. lower or higher depending on the relevant time frame at that time).

  205. Ragnaar said
    “Now with Lake Minnetonka tying the record for the latest ice out date “

    Why are you trolling? Lake Itasca in northern Minnesota had ice-out April 29.
    Science by personal astonishment is not science.

  206. Dave_Geologist says:

    Stephen, BBD can give his own answer, but mine would be “I know the difference between an incoherent bad argument (Monkton) and a self-consistent bad argument (Lewis).

    It’s been said before, but throwing a five in dice and saying that one of the faces is a five is a good argument. Claiming that all the faces are fives is a bad argument, but one that can’t be disproved with the information available.

  207. Chubbs says:

    Dave – The data is to too uncertain and the energy-balance model too limited to to tell if we have rolled a 4 or a 5. Below is the temperature difference between 1869-1882 and 2007-16 in observations and CMIP5 RCP6. We can’t say the obs+ model dice rolls were different based on this limited comparison.

    HADCRUT – 0.79
    HADCRUTCW – 0.88
    BEST – 0.96

    CMIP5 (air temp over ocean) – 0.98
    CMIP5 rough blend of land+SST like obs – 0.81

  208. The Very Reverend Jebediah Hypotenuse says:

    Mosher:

    …one whole part of my effort to carve out a lukewarmer place was to point out issues ( like sensitivity and RCPs) where people who were skeptical could stand and argue
    without having to be in denial.

    I usually don’t expend part of my effort to carve out places and point to issues, but when I do, I describe it as a public service to provide a safe space for standing and arguing and by definition not being in denial, or a moron.

  209. BBD says:

    Steven

    question. do you undetstand the difference between a good argument….say nic lewis using accepted methods

    Dave G more or less said it: NL does not make a good argument. As I am not a moron, this is obvious to me.

  210. Something which might be a bit pertinent is the new Christensen, Gillingham, and Nordhaus paper in PNAS which essentially says that estimates of variability economic growth through the 21st century used in climate forecasts are smaller in magnitude than both such estimates “from expert forecasts and an econometric approach designed to analyze long-run trends and variability.” To the degree to which such economic growth is self-propagating, and is only supported by intense energy consumption, the authors warn “Results from this study suggest a greater than 35% probability that emissions concentrations will exceed those assumed in the most severe of the available climate change scenarios (RCP 8.5), illustrating particular importance for understanding extreme outcomes.”

  211. @Chubbs,

    What are those? It would be good if you documented your numbers more.

    If those are temperature increases, which of the several vehicles to arrive at them are you assuming, in particular, ECS or TCS? And, whichever it is, are they based upon global averages, or just land averages where, after all, most of us live? Using the proper conditional expectation is important.

  212. Jesse says:

    I could use some clarification. On what basis are we saying that RCP 8.5 seems unlikely now? Are comparing current emissions to the scenario? If so, how are those emissions measured. How do those emissions compare to the other scenarios? Could someone provide a reference with the numbers rather than a picture of a graph?

    Would it be possible/better to compare the current greenhouse gas concentrations to the RCP pathway? That seems easier to measure than emissions, for one thing.

    I apologize if these questions are naive or have already been answered. I tried to catch up on the thread but I may have missed something.

  213. My point, I think, is that everyone seems to be assuming that the probability of an RCP10.5 is zero. While it might not be large, there is some probability mass out there, per the scenario sketched by @Dave_Geologist.

    From what I recently read, many of the people who elected Boss Trump still support him, mostly because they hate (and, indeed, that is their word, not mine) the “people on the coasts” for, they feel, having taken advantage of them. This is pertinent because it gives the @Dave_Geologist scenario plausibility.

    I, of course, would observe that if political votes were cast like voting stock, the regions on the coasts, including Texas in the south, contribute vastly more to USA GDP than those of the interior and, therefore, would have more to say about a “company”’s future. But, even if not, the consequences of ignoring the sentiments and preferences of the most revenue producing portions of the country in policy are probably not good.

    I learned today, for example, that in universities in the USA, accepted, strikingly great students from other countries (think eastern Europe, not Pakistan) are having a hard time getting student Visas under the current Set Of Rules, let alone the embarrassments and humiliations they might be subjected to in trips back home and here.

    This seems off the mark and topic, but I think it important to consider that the resurgence of the Age of American Unreason (per Jacoby) might have consequences deeper than mere policy inconveniences with respect to energy and climate. If our decision-making apparatus is hobbled or broken by the elevation of ignoramuses instead of the knowledgeable, practiced and gifted, and the technological pipeline feeding military superiority is blown up, the long term consequences for the United States are poor, both because of unpreparedness for climate change and because, frankly, those trends will mean we will suffer a humiliating and devastating military defeat at the hands of a smarter country who understands life is about more than the next news cycle.

  214. Jesse,
    In order to follow an RCP8.5-like concentration pathway, we’d probably need to keep increasing emissions until they were about three times what they are now. This seems unlikely, given that we’re already looking at ways to reduce emissions (even though we haven’t had any real success doing so, yet). However, many scenarios that do avoid RCP8.5 require technologies that have yet to be shown to work, and there are uncertainties that we could follow this pathway even if emissions are lower than predicted for such a pathway. So, my view is that it is probably unlikely, but not impossible (and the more people complain about it being used in scientific studies, the more likely it becomes).

  215. Peter Jacobs just highlighted a new paper, with William Nordhaus as one of the authors, that says

    Results from this study suggest a greater than 35% probability that emissions concentrations will exceed those assumed in the most severe of the available climate change scenarios (RCP 8.5), illustrating particular importance for understanding extreme outcomes.

    Hmmm, I wonder what Roger thinks?

  216. I missed that hyper had highlighted the same paper a few comments earlier.

  217. Steven Mosher says:

    “Stephen, BBD can give his own answer, but mine would be “I know the difference between an incoherent bad argument (Monkton) and a self-consistent bad argument (Lewis).”

    Weirdly from 2002 until Lewis published nobody had issues with the EBM approach.
    There is nothing bad about it. What is bad is assuming it is the final word.
    We have 3 basic approaches to estimating ECS. I will channel hansen ( i think it was him)since he said it best.

    1. We have a paelo approach:
    A) we know the phyics to be complete.
    B) The “observations” are uncertain
    2. We have the “observational” approach. (its not purely observational)
    A) The observations are more certain
    B) It is uncertain whether the physics expressed over the time period are complete.

    3. We have GCMs
    A) It is uncertain whether the physics are complete and accurate.
    B) Observations are more certain than paleo.

    I would say what I have said before. If this were any other feild people would just note the overlap in estimates and work to improve the methods, and raise issues, pro and con with all three
    approaches.

    If you asked me to rank the three approaches i would rank the paleo first. As for GCM versus EBM? dunno. I certainly would not call any of these approaches a bad argument. I didnt think gregory or otto were bad when they were done. The bad argument I think rests in trying to argue that we can be certain about which is “correct” I certainly would not use the Lewis approach to make a policy decision. I take it that you believe Dessler was wrong when he argued the method was imprecise, and you believe it is biased, ie bad. I await your peer reviewed publication showing that.
    I’d stick with Andrew’s claim that it may be imprecise, which is not too bad considering the complicated nature of the problem.

  218. Steven,

    There is nothing bad about it. What is bad is assuming it is the final word.

    Exactly. The criticism of Nic Lewis’ work is not that it’s somehow wrong, but that it is presented as if it is the final word.

  219. Dave_Geologist says:

    Steven

    There is nothing bad about it. What is bad is assuming it is the final word.

    What ATTP said. And what I said.

    saying that one of the faces is a five is a good argument. Claiming that all the faces are fives is a bad argument, but one that can’t be disproved with the information available.

    My first sentence = your first sentence
    My second sentence = your second sentence.

    The problem is not that LC18 makes one estimate of ECS. It’s that his acolytes claim it’s the One True ECS. IOW that all the faces are fives. And Lewis has form in its previous iteration, and to a lesser extent the new one but it’s early days, of (a) supporting them in that claim on social media, (b) claiming himself that it is the One True ECS (or at least, superior to the dozens of other estimates) and (c) dismissing out of hand peer-reviewed papers, not just social media comments, that he’s only seen one face of the die and it doesn’t tell us what numbers are on the other faces.

    LC18 is one of many estimates of ECS, and happens to be at the low end. That doesn’t make it the final answer, just helps to anchor the lower end of the distribution and shifts the mean or P50 downwards a tiny, tiny fraction. But not enough to matter for any practical purposes. That’s not how it’s being played. I wonder why?

    Interesting that you favour the palaeo estimates. So do I, although I acknowledge that I may have man-with-a-hammer blinkers. All the more reason to consider RCP8.5. If the palaeo data is right, ECS is about 50% higher than the IPCC’s preferred range. So RCP6.0 will give us something that looks rather like the IPCC’s RCP8.5 climate. Maybe not by 2100 or even by 2200, because the palaeo data can’t resolve such short timescales. But I presume there will still be humans on Planet Earth, and would not assume it will all be fine because by then they’ll be like the Jetson’s or the inhabitants of Trantor

  220. BBD says:

    Steven

    What ATTP and DG said.

    What is lukewarmerism if not presenting lowball sensitivity estimates as The True Knowledge?

    Forget your self-aggrandising and exculpatory crap about ‘<3C'. We are talking about lukewarmerism as generally practiced: a politically motivated exercise in evidence denial.

  221. paulski0 says:

    Sadly, Pielke Jr. appears to be winning his propaganda war:

    If you shout loudly enough about something people tend to back down to avoid further confrontation, doesn’t matter whether or not it’s true.

  222. Chubbs says:

    HyperGeo, values posted above are the temperature increase between the two periods used in L&C 2018. The CMIP5 model values are downloaded from KNMI explorer. The 2nd model value blends land air and SST in a .29 and .71 ratio, in a poor-mans attempt to get a model metric closer to observations which are also based on SST. The base CMIP5 surface temperature metric uses air temperature over oceans which runs warmer in the models than SST. The bottom-line is that the model results are not as far from the observations as indicated by the L&C2018 methodology. That can be easily seen by looking at any plot of model vs obs such as:

  223. Ragnaar says:

    “…but that it is presented as if it is the final word.”

    Warmest decade. Coral reefs bleaching. Arctic death spiral. Unprecedented. Not seen in the last 800,000 years.

    The skeptics don’t go away and progress is stalled. So I see final word approaches. They don’t work. Tucker Carlson interviewed Curry last night. Still in search of the final word.

  224. Ragnaar says:

    I didn’t read the paper either. This is from the carbon brief:

    “With climate change already having an impact on droughts, we can reasonably expect this impact to increase as the climate warms further. And model projections bear this out.
    The maps below give some examples according to simulations under a high warming scenario (“RCP8.5”) using 17 climate models.”

    A reasonable expectation.
    Our projections bear this out, using RCP 8.5.

    Why even mention this is there isn’t a reasonable chance it matters? If the carbon brief had a motto, it would be, It matters.

    The problem with all scenarios is you might as well be using economic models paired with whatever else you’re doing. Predict what poor Africa is going to do in the next 30 years.

  225. jacksmith4tx says:

    I’m seeing more stories about dead zones, algae blooms, super bacteria and noticeable imbalances in historic microorganism populations at the macro scale.
    At least one part of the food chain is going to love RCP 8.5!
    https://insideclimatenews.org/news/15052018/algae-blooms-climate-change-methane-emissions-data-agriculture-nutrient-runoff-fertilizer-sewage-pollution-lake-erie

    I think most of the changes in the biosphere due to human emissions and pollution will end up at the bottom of the food chain. It’s almost invisible to the public and by the time they realize we are in a terminal feedback loop it will be too late to change the outcome. Looks like we will have to resort to genetic engineering to adapt to our future.

  226. > Weirdly from 2002 until Lewis published nobody had issues with the EBM approach.

    Weirdly no evidence whatsoever is provided to substantiate this claim.

  227. paulski0 says:

    Ragnaar,

    You really need to look at all the words. The “reasonable expectation” in this case is simply that the drought impact they identify will increase with further warming. This is a scenario-independent expectation, which simply implies more warming = more impact.

    Why even mention what? That they used RCP8.5? Because generally in science it’s considered good practice to tell people what you did to arrive at your results. In this case, it seems that they used RCP8.5 primarily for the signal/noise benefits.

  228. The Very Reverend Jebediah Hypotenuse says:

    Dave-Geo:

    If the palaeo data is right, ECS is about 50% higher than the IPCC’s preferred range. So RCP6.0 will give us something that looks rather like the IPCC’s RCP8.5 climate.

    Well, that’s just great.
    That would mean that today’s ‘climate porn’ will be tomorrow’s ‘trending meme’.

    If the IPCC can’t get ECS right, one thing is for sure:
    We need better alarmists.

  229. BBD says:

    Do you mean ESS rather than ECS Dave G?

  230. Dave_Geologist said:

    “The oilier unconventional resources in the USA are essentially oil shales. So 50% of US oil production is oil shale, produced by drilling and fracking rather than mining. Which is probably the least environmentally unfriendly way to do it, but excludes thermally immature resources.”

    There is a significant difference between oil shale and shale oil according to the commonly used definition. Oil shale is really the hard to extract oil that is locked into the shale, whereas it’s better to refer to the shale oil from fracking or mining as tight oil so as not to confuse.

    Oil shale is the scary stuff, since it uses much more energy to extract, while tight oil is not as scary because it takes less energy and is not as common. The issue is as Pierrehumbert has noted, if we start extracting oil from Green River shale, then it’s game-over for emissions and the environment. We will use a hideous amount of energy and water to extract meager amounts of oil.

  231. @WHUT,

    The issue is as Pierrehumbert has noted, if we start extracting oil from Green River shale, then it’s game-over for emissions and the environment. We will use a hideous amount of energy and water to extract meager amounts of oil.

    This would be limited by economics, I imagine … How much energy does one need to dump in to get a certain amount of Joules out. On the other hand, and with irony, I note that electrical energy is getting pretty cheap to produce, so if that were adopted, and if there were still markets for oil, which I suspect there’ll be for a while, this could be done. I think the largest coal shoveling machine was electric, in its day.

  232. Required reading is this article by Raymond Pierrehumbert on oil shale
    http://www.slate.com/articles/health_and_science/science/2013/02/u_s_shale_oil_are_we_headed_to_a_new_era_of_oil_abundance.html

    And Pierrehumbert does not mention it, but scarce western USA water is also involved in oil shale extraction, maybe via steaming?
    https://www.onepetro.org/conference-paper/SPE-179610-MS

  233. izen says:

    @-Ragnar
    “Our projections bear this out, using RCP 8.5.
    Why even mention this is there isn’t a reasonable chance it matters?”

    It seems unlikely you have overlooked the previous explanations of why the extreme case is a good way to estimate impacts.
    Perhaps you just misunderstand.

    The projections from the extreme RCP8.5 scenario give the strongest evidence that the level of drought and climate impacts experienced so far are part of an ongoing increase in the probability of those impacts. It provides a means of estimating by linear interpolation, how bad things might get as we move along a path towards RCP8.5: even if we do not get that far.

    It also provides some (unjustified?) reassurance that things cannot get WORSE than the projections from RCP8.5 if we manage to stay within that limit.

    When we look for insurance against theft we do not insure half our possessions because there isn’t a reasonable chance of having ALL of them stolen

  234. Jon Kirwan says:

    Just to stir the pot a little more, there is this:

    “Uncertainty in forecasts of long-run economic growth”
    P. Christensen, K. Gillingham, and W. Nordhaus
    PNAS May 14, 2018. https://doi.org/10.1073/pnas.1713628115
    http://www.pnas.org/content/early/2018/05/08/1713628115

    “Results from this study suggest a greater than 35% probability that emissions concentrations will exceed those assumed in the most severe of the available climate change scenarios (RCP 8.5), illustrating particular importance for understanding extreme outcomes.”

  235. Steven Mosher says:

    “I usually don’t expend part of my effort to carve out places and point to issues, but when I do, I describe it as a public service to provide a safe space for standing and arguing and by definition not being in denial, or a moron.”

    Definitely not safe, since you get attacked by both deniers and morons.
    As illustrated by your post

  236. Everett F Sargent says:

    Here’s a real good reason to use RCP 8.5 …
    What Climate Sensitivity Index Is Most Useful for Projections?
    (Paywalled but you should know how to get a copy, if necessary. There are really good reasons for complete open access, as I’ve learned thorough recent experiences, speeds up understanding by orders of magnitude in time). A-R-R-R-R-R-R matey! #TalkLikeAPirateDay)

    “Abstract
    Transient climate response (TCR), transient response at 140 years (T140), and equilibrium climate sensitivity (ECS) indices are intended as benchmarks for comparing the magnitude of climate response projected by climate models. It is generally assumed that TCR or T140 would explain more variability between models than ECS for temperature change over the 21st century, since this timescale is the realm of transient climate change. Here we find that TCR explains more variability across Coupled Model Intercomparison Project phase 5 than ECS for global temperature change since preindustrial, for 50 or 100 year global trends up to the present, and for projected change under representative concentration pathways in regions of delayed warming such as the Southern Ocean. However, unexpectedly, we find that ECS correlates higher than TCR for projected change from the present in the global mean and in most regions. This higher correlation does not relate to aerosol forcing, and the physical cause requires further investigation.”

    And last paragraph …
    “It appears that ECS is in fact more useful than TCR for climate model projections of the 21st century in terms of indicating the magnitude of change for a prescribed RCP scenario. This is counter to the expectations since the time frame is generally considered to be in the realm of transient climate change, and added noise from aerosol forcing does not explain the results. More work and possibly the analysis of different model simulations are needed to understand and quantify the specific reasons for these relationships.”

    I actually do not understand the authors apparent confusion. 50-year trends are better for RCP 2.6 and RCP 4.5, while RCP 8.5 looks good for either 50-year or 100-year trends, but in general it looks like CMIP5 temperature trends need to be constantly above ~0.10C/decade.

    But if a study even mentions RCP 8.5, according to RPJr it should be discounted with a normalized value of -1 (+1 being highest and -1 being lowest in a +1 (very useful) to -1 (beyond totally useless as it permanently damages the entire field of climate science, or some such, as I can provide exact quotes from RPJr, if necessary, so not a strawperson) normalized state space in terms of utility.

  237. Willard says:

    Ragnaar,

    Perhaps you’d like to read my response to David, which triggered moderation most probably because I used the Very Dangerous word “ClimateBall”:

    > In situ measurements say of atmospheric pressure in a weather station and flight testing with pressure taps are not very different. In situ measurements say of atmospheric pressure in a weather station and flight testing with pressure taps are not very different.

    Repeating the same sentence twice doesn’t an argument make, David.

    There is a difference between a wind tunnel and real flight. Even if you measure the same parameters, you don’t measure the same thing. To paraphrase Norbert Wiener, the best model of a flying cat is a flying cat, preferably the same flying cat. Size does indeed matter in modelling nonlinear behavior. If you dispute that, you might need to read the thesis of a guy who spent a few years trying to reconcile the two.

    My point here is not to suggest that we can abstract away observations, but that when tackling complex problems, we need all the tools we have. Discussing wind tunnels is not that important for climate science, since we have yet to build such kind of model for the Earth. If we could have one, I’d be the first to cheer.

    I know that you bet on observations, as you said at James’ and repeat over and over again. The issue I have with this stance is simple – our climate data are very clunky compared to when we engineer stuff that needs to work because lives are on the line. This clunkiness should compel us to be very circumspect in following it blindly.

    Think of it this way. If an EBM gave you a sensitivity near zero, that would tell you either that physics doesn’t work as we think, that the data suck, a little of both, or else. Same if that EBM told you that sensitivity should be 9C. More iterations of measuring and modelling is required to move forward, using all the approaches and the frameworks we can. Cheering on the sidelines for one result and one result only won’t change that fact.

    It is a shame you don’t use your professional experience to make people learn about your turf. Making it your priority, instead of gainsaying for the sake of it, would improve the contrarian brand. The world needs better contrarians, David. ClimateBall is obviously not for you.

    https://judithcurry.com/2018/04/30/why-dessler-et-al-s-critique-of-energy-budget-climate-sensitivity-estimation-is-mistaken/#comment-872000

    I have no idea to what end David tries to gaslight me. Just imagine that I do what I do without understanding anything or by misreading or misrepresenting everyone. Wouldn’t that be a most amazing feat, worthy of a ClimateBall Daredevil?

  238. Joshua says:

    Definitely not safe, since you get attacked by both deniers and morons.

    Getting “attacked” in blog comment threads is dangerous?

    Maybe we should create a safe space for Steven?

  239. Well played, Willard.

    In unrelated news, I fear that I’m guilty of the crime of paleoblogology:

  240. Dave_Geologist says:

    There is a significant difference between oil shale and shale oil according to the commonly used definition.

    It’s the exact same rock, Paul, which is what I was getting at. I suspect not-a-lotta-people-know-that. In the same way coal is the same rock regardless of whether it’s strip-mined at surface or deep-mined from tunnels and adits, and salt is the same rock whether it’s deep-mined as at Winsford or solution-mined as elsewhere in Cheshire.

    Yes, the extraction technology is different, mining and retorting vs. drilling and fracking. And the latter is less environmentally unfriendly than the former (as long as you’re careful about water disposal)

    tight oil is not as scary because it takes less energy and is not as common

    .
    Not at. Shale oil (by my definition drilled-for) is vastly more common than oil shale (by my definition mined), both in terms of current production and remaining resources. For the simple reason that oil shale is drillable down to about 10,000 feet (where, with typical thermal gradients, the oil gets cracked to gas) while shale oil is really only economic where it can be strip-mined, i.e. down to a few hundred feet.

    I defer to Ray on climatology, but in this instance (I assume you refer to his Slate article), he’s wrong on several fronts (as is the Rapier Oil Drum article he refers to). Tight oil and tight gas are terms applied to conventional reservoirs (sandstones and limestones of low permeability by reservoir standards, with different cutoffs for oil and gas). Hydrocarbons migrated into them from a separate shale source rock and were trapped by sealing formations. That is business-as-usual reservoir geology, but generally needs fraccing for economic extraction. Conventional in-place and recovery factor methods are used to estimate resources. Climatologists don’t get to change the meaning of other fields’ terms, any more than I get to change the meaning of climatology terms 😉 . (You’ll notice I spell fraccing the way the industry has spelt it for half a century, not what the press changed it to ten years ago.)

    The Bakken and Eagle Ford are not like that. They’re organic-rich shales (hydrocarbon source rocks), which depending on their past or present temperature are mature for (= have generated or are generating) oil or gas. Those reservoirs form a subset of tight oil and tight gas, but are generally referred to as shale oil and shale gas (sometimes wet gas or liquids-rich shale gas, although that should properly only be used where the phase in the reservoir is gas or condensate (= a supercritical fluid)). Resources can’t be estimated by conventional means (people try but they’re really just guesstimates). Reserves are generally estimated by summing individual well decline curves, and by analogy for wells yet to be drilled. The only difference between the Green River and the Eagle Ford is that the Green River is less thermally mature. See Fig. 15 of this report. Only the bit in the north (~20% of Utah) is oil-mature (Ro > 0.6) and the far north is wet-gas mature. They can be exploited just like the Bakken, assuming other aspects are favourable. The immature stuff can potentially be exploited like the Estonian shales (which have an Ro of 0.3-0.5). Assuming it’s economically viable (I expect Estonia has open or hidden incentives to promote energy security). The stuff that’s too deep to mine? Economics will take care of that. The USGS is well aware of the role of thermal maturity, so I’d give their estimates credence. Something from a politician, promoter or huckster? Of course not.

    The bit that’s correct is that you can’t just frac the immature stuff, you need to heat it. 100°C is fine if you’re prepared to wait thousands of years, but 500°C is reasonable if you’re not. But why? It would be crazy-expensive and there’s plenty of cheaper oil to go after first. By the time that’s profitable we’ll have burned all the oil we can afford to under RCP8.5, let alone 6.0, and will only be using it for speciality chemicals which will be able to cover the extraction costs. There are some wacky ideas about pumping in superheated air and effectively setting it partially on fire, but none of that is even close to commercialisation, let alone regulatory approval.

    BTW it’s a mistake to look at tight oil gas decline curves (shale or conventional) as exponential. Ray’s graphs cut off too early. After the initial rapid decline the curve flatlines and carries on effectively forever. That’s because you’re dealing with a dual-porosity reservoir. The induced and natural fractures have a steep decline with a time constant of a small number of years. The matrix feeds into the fractures with a time constant of a large number of decades, and into the well as long as it’s open. Wells are usually abandoned when maintenance or operational costs exceed revenue, not when they stop flowing. Or when water-cut gets unacceptable. I can easily see half of the 20,000 Bakken wells carrying on in the low tens of barrels per day for decades. 200,000 bopd is not 6 million, but neither is it chump change.

  241. Dave_Geologist says:

    It also provides some (unjustified?) reassurance that things cannot get WORSE than the projections from RCP8.5 if we manage to stay within that limit.

    Unjustified izen. As per my PETM comments. RCP8.5/4°C takes us roughly to end Palaeocene temperatures, which had normal(ish) climate and vegetation. Adding another 4°C during the PETM threw us into a whole new climate over much of the world. Of course RCP8.5 with 6°C ECS would do that too….

  242. Dave_Geologist says:

    BBD
    I’m being a bit fast and loose between ECS and ESS because I’m making a longer-term case than 2100. That we should care about generations beyond our grandchildren. And thinking in terms of worst-case scenarios, rather than trying to put particular dates or % probabilities to it. In line with my recurring theme of “what must we avoid at all costs, even if it’s unlikely”. Which RPJr would no doubt call climate porn. But I know people who have modelled what would happen if a jumbo jet crashed into the Sellafield nuclear reprocessing plant, or if two tanker trains transporting nuclear waste to the site collided head-on. (Reassuringly, at least in the model, containment is maintained.) Is that nuclear porn?

    It should be possible for intelligent people to simultaneously consider likely outcomes and unlikely but far from impossible outcomes. And decide to discount the unlikely one if it’s just a bit more of the same. But actively seek to avoid it if the consequences are genuinely catastrophic, as opposed to straw-man catastrophic. We do it all the time in other areas. Airliners have two pilots. And twin-engined jets have to demonstrate extended single-engined operability to fly across oceans.

    As per PALAEOSENS, the larger part of the discrepancy is that the higher palaeo estimates include slow feedbacks and a like-for-like comparison falls within the IPCC’s ECS range (but note that their 3.1-3.7°C is decisively in the upper half of 1.5-4.5°C – no comfort there for luckwarmers). So yes, 4.5°C is in the middle of a bunch that are more like ESS. But they go up to 6°C, and higher if you include some Pleistocene and PETM estimates. So I could make 4.5°C as half-way between ECS and ESS.

    And in my previous post I should have used ESS. Because if we’ve baked in a PETM, in 500 years time our descendents will have to live with a world which would be unlivable in modern terms. Hence Trantor as an analogue (covered or underground cities with hydroponics, supplemented by food from farming planets, or in our case, orbital hydroponics farms)

  243. The Very Reverend Jebediah Hypotenuse says:


    Definitely not safe, since you get attacked by both deniers and morons.
    As illustrated by your post

    All victim cards are equal. But some are more equal than others.
    As illustrated by your post.

    If only morons wouldn’t “attack” vacuous rhetorical puffery, blogs would be so much safer.
    But they’d be less funny.

  244. Dave_Geologist said:

    “In the same way coal is the same rock regardless of whether it’s strip-mined at surface or deep-mined from tunnels and adits, and salt is the same rock whether it’s deep-mined as at Winsford or solution-mined as elsewhere in Cheshire.”

    That’s weird. I thought different types of coal, such as anthracite, bituminous, and lignite are different types of coal. Lignite is an immature form – barely beyond peat – in terms of a transformation from organic material to fossil fuel. Thus, Green River oil shale is also an immature form and so is categorized differently. Salt is different because it is a well-defined compound, yet it doesn’t have to be a rock because it gets dissolved in sea-water

    This is the way the fossil fuel resource abundance is generally understood, as a pyramid where the width is proportional to amount available.

  245. BBD says:

    @Dave G

    As per PALAEOSENS, the larger part of the discrepancy is that the higher palaeo estimates include slow feedbacks and a like-for-like comparison falls within the IPCC’s ECS range (but note that their 3.1-3.7°C is decisively in the upper half of 1.5-4.5°C – no comfort there for luckwarmers). So yes, 4.5°C is in the middle of a bunch that are more like ESS. But they go up to 6°C, and higher if you include some Pleistocene and PETM estimates. So I could make 4.5°C as half-way between ECS and ESS.

    Thanks for this – we are on the same page. You had me worried there for a moment 🙂

  246. Dave_geologist said:

    “BTW it’s a mistake to look at tight oil gas decline curves (shale or conventional) as exponential. Ray’s graphs cut off too early. After the initial rapid decline the curve flatlines and carries on effectively forever. “

    That’s probably true. The flow of oil from these sites is largely controlled by diffusion, which is apparent from the early spike and 1/time fat-tails. In physics, effective diffusional range is controlled by the Ornstein-Uhlenbeck model.

    This is data from a typical Bakken well, provided by the North Dakota Industrial Commission. Essentially half of the cumulative production is within the first couple of years according to a O-E model. It’s perhaps a third if unbounded diffusion occurs.

  247. Steven Mosher says:

    “The problem is not that LC18 makes one estimate of ECS. It’s that his acolytes claim it’s the One True ECS. IOW that all the faces are fives. ”

    Yes, recall what started all this. My claim that his argument was not bad. What I specifically mean
    is that the argument as presented in the Peer reviewed literature is not bad.

    Of course in the hands of ridley and others ( including Nic) the assumption that it is a final word is
    not a very good argument.

  248. Dave_Geologist says:

    Venn diagrams Paul.

    Anthracite, bituminous, and lignite are different types of coal but they’re all coals. I could have said bituminous coal is the same rock whether it’s mined or quarried. Or lignite. Or whatever. Gas-mature, oil-mature and immature oil shales are all oil shales. The higher ranks or maturities form at greater depth and temperature (primarily temperature), but geology moves things around and you can find high maturity anthracite at shallow depth and lignite 2000m deep in North Sea wells. You tend not to get deep lignite mines (a) because it has a lower value per ton, and it’s lower density so you need more volume per ton, so it would be uneconomic to deep-mine, and (b) the country rocks tend to be weak so it would be hard to keep shafts and adits open.

    Thus, Green River oil shale is also an immature form and so is categorized differently

    Some Green River oil shale is immature, some is mature and some is a bit over-mature for oil, as per the USGS report I linked to. I should have been a bit more precise. The rock is oil shale, the industrially-extracted resource is shale oil or shale gas. The fundamental difference between shale oil or gas reservoirs and conventional tight reservoirs is that the source rock is also the reservoir. That’s completely different from conventional oil and gas reservoirs however tight, and lumping them together just because they both require fraccing but don’t require exotic technologies like partial burning is not at all useful.

    BTW the waxiness Ray alludes to is a red herring. That’s just down to the particular nature of the lacustrine source rock. Pretty much all terrestrial source rocks are like that. It’s to do with the materials in the cell wall, IIRC an adaptation to coping with the terrestrial rather than the marine environment. Even when it’s oil-mature it’s still waxy. For example, the Beatrice oilfield in the North Sea is sourced from Devonian lacustrine shales and still has 30% wax even though it’s 40° API. Under reservoir conditions the wax is dissolved in the oil and it flows like petrol, but at room temperature it’s solid. You don’t have to heat it up to 500°C to make it liquid, just 20°C (its pour point). The 500°C heating is nothing to do with the wax. It’s to mature and crack the organic molecules and drive off N2 and O2. The wax, unfortunately, is resistant and just goes along for the ride. It even survives up to gas condensate temperatures. The Erskine HPHT gasfield is currently shut in because the export pipeline was blocked by wax accumulation. Refineries would cope with Green River oil just fine. There’s lots of waxy crude on the market already and some refineries specialise in it, just as some specialise in heavy oils.

    This is the way the fossil fuel resource abundance is generally understood, as a pyramid where the width is proportional to amount available.

    Indeed, and it shows shale oil and shale gas as bigger than conventional. The opposite of the viewpoint you were proposing 😉

  249. Dave said:

    “Indeed, and it shows shale oil and shale gas as bigger than conventional. The opposite of the viewpoint you were proposing “

    Please quote what viewpoint I was proposing. I said that Bakken-like tight oil was less common than oil shale, which is borne out by the pyramid. From Pierrehumbert’s article: “the Green River shale under Colorado, Wyoming, and Utah has a whopping 2 trillion barrels”. That’s on the order of all conventional crude oil reserves worldwide (cumulative extracted plus to be extracted reserves).

    In the USA, we have a problem with over-leveraging of funding for all the tight-oil plays. At current oil prices, it’s up in the air as whether they make any money. But because of society’s requirement for crude oil, somebody will extract it. In that cited article, Pierrehumbert talks about the Red Queen race to sustain production levels. That term was coined on a now-defunct energy blog several years ago, and I had actually described the situation on my blog w/o invoking the term “Red Queen”. I called it Gold Rush dynamics, but indeed Red Queen is a better descriptor.
    http://theoilconundrum.blogspot.com/2012/05/bakken-growth.html

  250. Dave_Geologist says:

    Paul, I assumed that you and Ray thought that the Green River Shale was unexploitable. Therefore not resources. And so smaller than Shale Oil and the pyramid is not-quite-right. Reserves are a subset of Resources which are a subset of In-Place. Resources does not equate to In-Place, although people do tend to get them confused. Resources means exploitable, although perhaps not with the current price or technology. Or just not worked yet in significant detail. But it needs to be more than just pie-in-the-sky.

    Although actually I probably disagree with that part of the pyramid. Unless you move the goalposts and artificially put the Oil Shale/Shale Oil boundary in a place which guarantees more shale oil. As I said they both start with the same rock. Assume a uniform statistical distribution with depth, a constant geothermal gradient, zero maturity at an average surface temperature of 20°C, oil window starts about 60°C, gas starts about 100°C, the sort of liquids-rich wet gas which produces much or most of America’s “shale oil” up to 120-130°C and dry gas from 150°C. Non-gassy shale oil and immature oil shale then fill equal depth slices. Gassy oil and wet gas probably add about the same as non-gassy shale oil (because the recovery factor will be better due to its lower viscosity). So at best they’re equal and shale oil is likely bigger. But most continental rocks have experienced uplift and erosion so are not zero maturity at the surface. Which eats mightily into the immature slice. A couple of kilometres of erosion removes it entirely. And lots of this stuff is in extensional basins which had higher heat flow in the past, which eats into the bottom of the immature slice. So I’m pretty sure the In-Place is bigger for shale oil than for oil shale (taking the break point at oil maturity (Ro 0.6)). I expect recovery factors to be better too. Partial combustion is the only way I can see subsurface oil shale being technically feasible which by definition leaves less oil to be recovered. So now that I’ve thought about it, I believe oil shale is the exception which (dis)proves the rule as far as pyramids go.

    BTW, Resources can never match In-Place without the help of Maxwell’s Demon, which is why you need two separate terms. There’s a petrophysically defined Reservoir Technical Limit which for oil is typically no more than 8% for depletion without injection support, and 40-50% for water injection. If you drilled a well every foot and left the wells open until the heat-death of the Universe, or flushed water through the reservoir until then, you wouldn’t get any more. It’s built into the rock physics. For gas it’s about 90-95% (or about 70% in practice if there is an active aquifer). For oil you can get up to 50-60% with Tertiary Recovery like gas cycling (Huff’n’Puff) or by putting fancy chemicals in the water. And that’s in conventional reservoirs.

    I agree there’s a lot of hype around, especially in the US where it’s onshore and can be done by small-scale operators. Therefore a lot of it gets funded by people who’ll be Angels for a movie or pop song the previous week or asset-strip a failing company the following week. So (a) there are mugs out there to be taken and (b) there are investors who don’t have the technical background that I would have had to face in seeking funding for a project in a major oil company.

    As I said earlier, we should all hope this discussion is moot because if Utah does go to the extent of subsurface retorting it will be because we’re running out of existing resources and the oil price has soared to $500 or $1000 per barrel (prepares to be shot down for venturing into economics 😉 ). We’ll have blown RCP8.5 big-time if we get to that stage.

  251. Where did I see Green River shale was unexploitable? Elsewhere in this thread, I said that “if we start extracting oil from Green River shale, then it’s game-over for emissions and the environment”. The fear is that it will take almost as much energy to dig up and refine the resource as we will gain from combustion. Plus all the water that would be used.

    What is scary is if someone devises a way to use the extracted energy to extract more energy. Then even an EROEI ratio of slightly greater than 1 may be viable. So, in a hypothetical situation of an EROEI of 1.1:1 we will be essentially using 1000 barrels to produce 100 barrels of marketable refined oil, but also balloon emissions by 10x for the same productivity that we have now.
    That’s why the game-over designation is used.

    Don’t put it past the criminals in the Trump admin to go down this road. Trump’s Secretary of the Interior is already selling off national monument areas in Utah for just this reason. So far Green River is safe since that’s in NE Utah whereas the 2 national monuments sold off are in SE Utah last I checked.

  252. Dave_Geologist said:

    “As I said earlier, we should all hope this discussion is moot because if Utah does go to the extent of subsurface retorting it will be because we’re running out of existing resources “

    Of course we’re running out of existing resources. That’s the definition of a non-renewable resource. Why else did they even open up Bakken for wide-scale hydraulic fracturing? It had been producing low-level, at least a couple million barrels per month for years, but the time had come to go full-on and the USA got some respite, at least for several years. Soon, the Bakken will decline as well.

  253. @WHUT, @Dave_Geologist,

    I’m my opinion, all this supply-side energy stuff is self-limiting in its utility. I am much more interested in demand side changes and their implications for energy consumption.

    While you might not agree with Ramez Naam (see also) in the following, it is true (a) conventional institutions and the public have a really difficult time parsing what he refers to as exponential technologies, (b) the product adoption curve of a superior product is a logistic function, which is actually super-exponential for the main portion of its climb, and (c) companies with a recent history of financial success have a really hard time realizing their run is at an end, and they need to deeply invest and transform themselves into being a start-up again. On the latter, it’s their Kodak moment.

  254. I think the logistic is exponential growth initially and then it reaches diminishing returns.
    This is the logistic differential equation, where P is the cumulative growth:
    dP/dt = k P (1-P)

    First term on the RHS is exponential and the negative term provides a diminishing return feedback

  255. Dave_Geologist says:

    Sorry Paul, I misread you on the Green River. It was the Slate article that challenged its exploitability, based on the linked Oil Drum article.

    The misconception is that it would be produced by a similar mechanism to steam-flooding tar sands. From a quick look most of the publications on steam injection in oil shales are modelling only moderate heating (to about 150°C), so that would only work for already-oil-mature shales. And even then it’s challenging e.g. this paper couldn’t get it to work.

    Steam-flooding to 500°C would indeed be hugely energy intensive. Probably an order of magnitude more energy intensive than tar sands based on the temperature increase required, which would certainly require more energy than you’d get back by burning it as fuel. So you’d only do it if you had a cheap fuel source to make the steam. Probably nuclear or renewables, so low-carbon or carbon-free)I don’t see the price differential between coal and oil ever getting so big that it would be economic to site coal-fired boilers above the oil-shale fields). At BAU electricity prices, the product would be hugely expensive. You’d need an oil price of many hundreds of dollars per barrel to make it work, which pretty much by definition means the product isn’t being used to fuel cars. We’d be back to the days of the Scottish oil shale industry, when it wasn’t used as fuel but for petrochemicals and for niche markets like lamp-oil. Maybe to fuel aircraft if batteries still aren’t up to it.

    The Estonian oil shale industry is different from the former Scottish one. They’re not retorting the shale to extract oil, they’re just burning it in power stations like coal. For that there is an advantage to using an immature oil shale, because maturation involves a volume increase, which together with buoyancy means some of the oil has inevitably been expelled from the shale (that’s where the oil in conventional reservoirs comes from).

    Immature-oil-shale-as-as-fuel is more likely in my view to be produced by controlled partial combustion (low-oxygen, without flames, like an underground coal or peat fire). In that you sacrifice part of the resource underground, using the heat liberated to retort the remaining shale. I’ll retract my previous comment about that method giving a lower recovery factor than fraccing. On reconsideration, the heat (= lower viscosity), generation of gas in hot spots and thermal fracturing might increase the recovery factor from the remaining shale enough to offset the loss of the stuff you’re burning.

    This also looks quite challenging (e.g. this paper looks at injecting catalysts to promote the maturation process, which suggests that simple burning doesn’t cut it). But obviously that depends on product price. The biggest issues though will be around that magic word “controlled”. Underground fires are not difficult to start. They occur naturally and most coalfields have examples of a seam which burned naturally underground millions of years ago. But there was no-one around in the Carboniferous to worry about what happens if it gets out of control.

  256. Dave_Geologist says:

    To be clear I’m not advocating subsurface retorting of oil shales as a fuel resource. Although it’s worth keeping in mind our ingenuity when people say “there isn’t enough fossil fuel to deliver RCP8.5 so ditch it”.

    We shouldn’t forget though that before the 20th Century, oil was an expensive commodity. Too expensive simply to burn as fuel. But just as it had other uses then, it has other uses now and will have other uses in the future. If we squander it now, our descendants will either have to resort to exotic extraction technologies or build organic molecules piecemeal from simple CNOH precursors.

    Indeed I would argue that as part of our moral stewardship of the planet, we shouldn’t just avoid leaving our descendants a massive pollution headache to clean up. We should husband our natural resources responsibly and leave some for the grandkids and their grandkids.

  257. Okay, my turn to be guilty of sloppy speech. Regarding,

    … the product adoption curve of a superior product is a logistic function …

    I should have written S-curve instead of logistic function.

    But in any case, it does not help that there are so many different kinds of S-curves, or that there isn’t really a logistic function but a parameterized family of them. So, I was speaking sloppily. What I actually meant was the product adoption curve, such as the Bass diffusion model, and I was thinking specifically of adoption of solar PV, for example, by households. Results are similar for other applications.

    The estimate of market share from Bass at time t is F(t) = \frac{1 - \exp{(-(p+q)t)}}{1 + \frac{q}{p}\exp{(-(p+q)t)}}.

    To illustrate, I’ve written a little code based upon an estimate of the p and q values for household solar PV adoption, dating from 2013:

    # Bass diffusion model compared with exponential and logistic.

    bdm<- function(t, p=0.0914, q=0.1036)
    # Coefficients above for solar adoption from: http://www.icmconference.org.uk/index.php/icmc/ICMC2013/paper/viewFile/779/218
    {
    # Instantaneous, or point-in-time.
    # See https://en.wikipedia.org/wiki/Bass_diffusion_model.
    # See also: https://www.immagic.com/eLibrary/ARCHIVES/GENERAL/WIKIPEDI/W101203B.pdf
    # See also: http://www-bcf.usc.edu/~tellis/Diffusion.pdf
    # See also: https://ocw.mit.edu/courses/sloan-school-of-management/15-871-introduction-to-system-dynamics-fall-2013/assignments/MIT15_871F13_ass4.pdf
    # See also: http://weblab.com.cityu.edu.hk/blog/chengjun/files/2012/04/Bass-Diffusion-Model.pdf
    # And, finally, see: https://en.wikipedia.org/wiki/Generalised_logistic_function
    stopifnot( 0 < p )
    p.q<- p + q
    F<- (1 - exp(-p.q*t))/(1 + q*exp(-p.q*t)/p)
    L<- 1/(1 + exp(-q*t))
    E<- 1 - exp(-q*t)
    return(list(bass=F, logistic=L, exponential=E))
    }

    t<- seq(0,18,0.01)

    Y<- bdm(t=t)

    plot(t, Y$logistic, type="l", lwd=3, col="green", xlab="time",
    main="Bass vs Logistic vs Exponential\nin the case of adoption of household solar PV",
    ylab="market share", ylim=c(0,1))
    lines(t, Y$exponential, lwd=3, col="orange")
    lines(t, Y$bass, lwd=3, col="navy")

    legend("bottomright", c("Bass", "Logistic", "Exponential"), col=c("navy", "green", "orange"), cex=1.0, lty=1, lwd=3)

    I used a generalized logistic function form for the corresponding logistic. As the Wikipedia notes, when p = 0 the Bass becomes logistic, and when q = 0 it’s exponential.

    The result looks like:

    Sorry for the confusion earlier.

  258. Dave_Geologist says:

    Back to “What Climate Sensitivity Index Is Most Useful for Projections?”

    I can think of a couple of reasons for TCS past/ECS future.

    1) Slow climate mode reconciles historical and model-based estimates of climate sensitivity.

    A Bayesian methodology applied to 24 models, however, documents curvature in the radiative response to warming from an evolving contribution of interannual to centennial modes of radiative response. Centennial modes display stronger amplifying feedbacks and ultimately contribute 28 to 68% (90% credible interval) of equilibrium warming, yet they comprise only 1 to 7% of current warming. Accounting for these unresolved centennial contributions brings historical records into agreement with model-derived ECS estimates.

    So how about this. The models tend to agree about the short-term modes because they’re well constrained and in-our-face. And for them, there isn’t much difference between TCS and ECS because we’re still in short-term territory (most of the warming occurred in the last 50 years and so far we’ve only seen the long-term mode from 19th Century forcings). The models differ a lot in their long-term modes (i.e. in how much the radiative response to warming curves over centuries) and they dominate future ECS. It’s a cousin to the Dessler et al. ciritcisms of Lewis & Currie. Models which give a very similar ECS in observations to 2015 give very different ECS’s in projections to 2100 and beyond.

    2) Possibly related. Some of the feedbacks such as surface albedo changes kick in more slowly in the real world than in the models. E.g. trees and grass don’t disappear overnight, they gradually wither and decay. As the Sahel moves north, it will take time for vegetation to grow or for farmers to gain the confidence to plant crops. Farmers combat drying by increasing irrigation. Etc.

  259. Dave said:

    “Immature-oil-shale-as-as-fuel is more likely in my view to be produced by controlled partial combustion (low-oxygen, without flames, like an underground coal or peat fire). In that you sacrifice part of the resource underground, using the heat liberated to retort the remaining shale. “

    Imagine that 10x as much of the oil shale is combusted in situ than is ultimately extracted. The 10x escapes as emissions obviously. That’s where the carbon tax will be an important factor if it can be enforced. No one will use that approach if the tax is high enough.

    Or forget about the tax, and just make that kind of extraction process illegal.

  260. Dave_Geologist says:

    We don’t have to imagine if it’s 10:1 Paul (i.e. an EROI of 1:10). Someone’s already done the work for us Energy Return on Investment (EROI) of Oil Shale. EROI is about 1.2–1.6:1. if you include internal energy (gases and char produced as by-products of retorting, which are burned on-site as fuel to supplement imported fuel) or about 2.4–15.8:1 if you only include external energy (supplies imported from offsite). Obviously from a CO2 emissions viewpoint you should use internal energy. Especially for surface retorting where the CO2 goes up the flue. Maybe less so for subsurface retorting, where some (most?) of it will stay in the ground. Where it will help the oil to flow and increase recovery factor, although you then have to consider what you do with the CO2 you strip out of the oil before sale. In a conventional heavy-oil CO2 flood it would be recycled into the reservoir because you’re paying for the imported CO2 and want to re-use as much as possible. Absent regulation or carbon taxes, the most economic option would be to vent it.

    Another way of looking at it is that the EROI is (say) 10:1 if you ignore negative externalities and just consider the profit-and-loss account, but only 1.5:1 if you include externalities, e.g. via a carbon tax. That makes immature oil shale potentially very threatening in a world with no CO2 constraints. For surface retorting you could presumably go down the path of importing nothing to fuel the boilers and just using raw oil shale as fuel, like in the Estonian power stations. You’d have a huge EROI, because all you be importing is electricity for lights, pumps etc. and fuel for trucks and diggers. Or maybe that’s why there’s the huge difference between 2.4:1 and 15.8:1. Some projects do that already. At any site you presumably make a trade-off between the cost of burning imported fuel and the revenue loss from burning some of your saleable product, instead of just burning the unsaleable stuff.

    In that case subsurface controlled combustion would look to have an excellent EROI, maybe 10:1, not 1:10. As long as you ignore the negative externalities, principally CO2 emissions. Just like the oil and power generation industries do now, for the most part. You can’t afford to import combustion fuel and inject it down thousands of wells, so of course you’ll sacrifice some potential product by burning it instead. So to return to RCP8.5’s viability, I am even more convinced that Ray and the Oil Drum article are wrong to discount the possibility of the Green River and other immature oil shales contributing to emissions. If there is no penalty for CO2 emissions, or no regulatory ban, it will happen when the oil price gets high enough.

  261. Dave said:

    ” That makes immature oil shale potentially very threatening in a world with no CO2 constraints.”

    Exactly. Self-sustaining extraction is a strong positive feedback factor that doesn’t seem to get much traction. If it gets swept into the EROEI calculation implicitly, then the ratio looks favorable, whereas it actually has disastrous consequences.
    Pierrehumbert is one of the few that have written about depletion and its implications.

  262. Dave_Geologist says:

    Actually there’s something to be said for underground over surface retorting as far as CO2 emissions go. They’ll certainly be less, quite possibly a lot less. Although not less than surface retorting with full CCS.

    Above about 30°C and 1000 psi, CO2 is a supercritical fluid with density about 0.8 g/cc. Say deeper than about 2000 feet. If I was planning it, I’d want to start deep rather than shallow anyway. More leeway and time to respond if things go wrong. Don’t want your first commercial development setting fire to cornfields a few years in. Very bad PR. You’ll also get more benefit from natural gas lift if you start at higher pressure and so need less pumping (I expect the oil to be gassy because you won’t be able to control combustion well enough to avoid gas-generating hot spots and left-behind cold spots).

    You also want the CO2 from combustion to be supercritical because then it’s more miscible with oil. Also much denser than CO2 gas, so you get more CO2 molecules per unit of contact area with the oil. And that also means less volume increase, so less chance of the combustion products building enough pressure to fracture out of zone. In CO2-flooded oil reservoirs, about half the CO2 injected comes back with the oil. You’d have the same venting or CCS choice to make as for surface retorting, but it’s probably easier to capture because it’s already in pipework and tanks rather than mixed in with other flue gases. The CO2 that doesn’t mix with the oil will initially stay down there, but although it’s nothing like as buoyant as gas (about the same as oil), it is less dense than water so will tend to migrate upwards. Depending on the oil you generate, the CO2 can be denser than oil and sink to the bottom of the reservoir. It then has to migrate past the oil pool before it can move upwards. You probably want to aim for quite a light, gassy oil anyway to minimise the left-behind cold-spots and aid recovery. So I expect the end result to be an oil-CO2 solution on top and excess CO2 below.

    The CO2 will ultimately migrate upwards through buoyancy, barring the presence of sealing formations and trapping structures. But unlike oil, CO2 is (a) soluble in water and (b) reacts with the rocks it’s passing through. So you can guarantee not all of it will get to surface. How much and how long it takes would be for the modellers to evaluate. There’s already “an app for that”. E,g, Trinity or PetroMod. They’re used for petroleum systems basin modelling and already have oil and gas generation and migration rates built in. You shouldn’t distrust them just because they’re models. They’re very much the same sort of physics-and-chemistry-driven 3D models as are used in climatology and reservoir engineering. You just have to add the CO2 properties and parameterise a miscible-CO2 black-oil model. 99% of the work has probably been done already in support of CO2-flooding. It may already be built in to support the CCS market.

    Not that I’m advocating we do this any time soon, but it does make for an interesting intellectual exercise 😉 .

  263. Pingback: Rethinking climate policy | …and Then There's Physics

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