IPCC AR6

I gather that the IPCC plans to continue in a manner similar to how it’s operated in the past. It seems that Stoat thinks they should be considering shorter, more focused, reports. Judith Curry illustrates her subjectivity by suggesting it needs to regain it’s scientific objectivity.

Given that I don’t really have a great deal of knowledge of the long history of the IPCC and what’s worked and what hasn’t, I don’t have particularly strong views. One of my views, though, is that what I would like to know more about is the actual impacts of climate change. I understand the physical science quite well: if we continue to increase our emissions, temperatures will rise, sea levels will rise, sea ice and ice sheets will melt, precipitation patterns will change (the hydrological cycle will intensify). What I have less of a handle on is what actual impact this will have on us and on the biosphere. I know that there is a lot of work about this, and I am aware of some of it, but it seems to be much less clear than the actual physical science.

So if I had a say – which of course I don’t – I would think that ensuring that there’s a focus on the actual impacts – and that this information is both noticed and accessible – would seem sensible. This is probably related to the view expressed by Stoat: there just seems to be an immense amount of information released in a very short space of time, and so lots of interesting – and relevant – things can just end up lost in the noise. So, I’m sure it’s all there, it’s just quite hard to find and to notice (okay, I am also lazy). It also seems that this is ultimately what’s relevant and where I sometimes struggle in discussions: I’m never quite sure how best to respond to comments of the type – “okay, so temperatures will go up, sea levels will rise, oceans will acidify, ice will melt, precipitation patterns will change; so what?”

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107 Responses to IPCC AR6

  1. I agree that a lot more could be done on the impacts [although I would say that: my job titles are ‘Head of Climate Impacts Research’, and ‘Chair in Climate Impacts’ 🙂 ]

    Interesting that you see impacts research as lower profile though. The IPCC Working Group 2 report covers impacts, but it’s important to consider whether your perspective is widely-shared (I suspect it is) and why.

    Although there is a huge amount of research being done on climate change impacts, arguably it is still fairly fragmented and disorganised and not yet becoming more than the sum of its parts. In contrast, the climate modelling community (of which I am also a part) has got itself reasonably well-organised in cooperating as a community, to do big, coordinated studies like CMIP which I think help a lot with exploring confidence and uncertainties. This is why IPCC Working Group 1 is able to make some fairly nuanced and well-grounded statements on confidence and likelihood etc. The ‘impacts community’ is much looser, so the IPCC Working Group 2 is really mostly still trying to assess and make sense of a vast number of individual studies. Having been a lead author in WG1 in AR4 and then WG2 in AR5, I can confirm that the latter was a harder job!

    So a key question is, should the ‘impacts community’ try to coordinate itself more and do ‘big science’ like the climate modelling community? There’s been a bit of a move towards this already, with the Inter-Sectoral Impacts Model Intercomparison Project (ISI-MIP, and in the first phase of this we did get some interesting papers coming out.

    What do people here think of this? Is this going in a useful direction?

  2. Richard B.,

    Interesting that you see impacts research as lower profile though.

    That wasn’t really what I was getting at. I was admitting, firstly, that as a physical scientist I understand the physical science better than the impacts and that, given the immense amount of information that’s released, it’s quite hard for someone like me (a physical scientist who is also lazy 🙂 ) to extract the key points about the likely impacts. So, not so much that it has a lower profile, but maybe not high enough.

    So a key question is, should the ‘impacts community’ try to coordinate itself more and do ‘big science’ like the climate modelling community?

    Yes, I do think that sounds sensible. My feeling is that the impacts are what’s really important. Saying “it’s going to get warmer” doesn’t really tell you what impact that will have. If I have learned anything in the last couple of years, it is that simply pointing out the well known physical consequences of increasing our emissions (warming, sea level rise, hydrological cycle,…) really doesn’t tell people the actual impacts of such changes, and I certainly don’t have a particularly good handle on these myself.

  3. Andrew Dodds says:

    The response to the last point is difficult.

    The problem is that for the majority of people in 1st world societies – the top 80% or so at least – have lived for decades in a situation where the basics of life – food, water, electricity, housing, physical security, disaster relief, etc – appear inviolable, as in ‘they just happen’, just as the air is always breathable, everyone lives into their 70s, and if anything does go wrong than you can just call 999.

    This has bred a huge amount of complacency. One obvious example is the anti-vaccination brigade – by definition they only exist because they ‘no one dies before their 70s and you can just call 999’ as part of their mental background. Another (just to annoy..) would be those advocating an energy supply based entirely on intermittent renewables. That’s not something you can do without an a priori belief that the lights will stay on because the adults are in charge. And just don’t ask about Internet Libertarians(tm).

    And so with global warming. If the concepts of absolute food shortages, floods where there have never been floods before, productive land turning to desert, sea floods that never go back – that things could go irrecoverably wrong – are just not part of your mental background, then you can dismiss them.

  4. I agree very strongly with the 3 views expressed so far. Explaining likely impacts in terms the general public can understand is critical. I know for scientists it’s probably a woolly area and therefore one where they’re reluctant to stick out their necks, but if there are climate-related dangers ahead then the public need to understand them.

    I heard someone describe our situation as like being on a raft drifting down the middle of a river. In the distance we’ve heard a roar which is getting louder. Do we start paddling for the bank now or delay until until we’re certain that that the roar is a waterfall? By then we might have left it too late to reach the bank.

  5. The impacts are ultimately local, even effects that are basically similar have different impacts under different conditions. As long as the temperature change is small enough there’s no obvious reason to expect the overall net effect would be either positive or negative. It may be one or the other, but we cannot tell even the sign – and even if we knew all the effects, we might disagree on the sign of the aggregate total, because the effects are not commensurable without value judgments.

    Doing unbiased research and assessment on such an issue is really difficult. It’s obvious that many selective biases affect the choice of subjects for study, and before that whether a person gets interested in such research. Governments of individual countries have often strong vested interests in the results. This has, indeed, be very obvious in the related IPCC activities, where representatives push the interests of their governments. A major part of the publications is not from independent academic research that has been refined through interaction of independent research groups, and reached the level of established scientific understanding. Reports that have not gone through real peer review are the rule rather than exception.

    The issue is very important, but really problematic for science.

  6. Pekka,

    The issue is very important, but really problematic for science.

    I suspect this is true, but presumably there must be some impacts about which we have more confidence than others. Having a better handle even on this would be very useful.

  7. What I wrote above was on the impacts of little warming. The impacts of stronger warming are more essential, but not much easier for science, because we know so little on what the physical effects of large increases in CO2 concentration are.

    That uncertainty means that the most important issue concerns decision making under great uncertainty. That’s again a very different field from analysis of impacts, and in the realm of WG3 rather than WG2.

  8. aTTP,

    What I see as a very large problem is the selective bias introduced in picking a few impacts out of very many.

  9. verytallguy says:

    ATTP

    there must be some impacts about which we have more confidence than others

    I think the table in WG2 SPM sets this out quite well, with level of impact and ability to adapt set out visually plus level of confidence alongside in words. An extract:

  10. Rachel M says:

    I would like to see more written about the impacts of climate change too and not just from a very abstract and unemotional scientific viewpoint but on a more personal level. It’s very hard for humans to imagine how something bad (or good) will affect them personally until it actually happens.

    When I first moved to Auckland and was still jittery from the Christchurch earthquakes I was reluctant to go into the CBD from our home on the North Shore unless my children came with me. There’s just one bridge connecting Auckland city with the North Shore and if something happened, like a volcanic eruption (which is expected for Auckland at some stage) then I was worried I wouldn’t be able to get back to my children. A friend of mine tried to reassure me by saying I could catch the ferry. I found it interesting that she thought the ferries would be still going back and forth during a volcanic eruption. I mean, they may be but I doubt it. After the big earthquakes in Christchurch the buses stopped. They didn’t continue ferrying people around. The roads were damaged and some unusable. The whole city came to a stand-still. Even supplies of toilet paper ran low at one point. There was no running water and people were digging holes in their backyard for toilets.

    It’s as Andrew says, we have become complacent. We’ve got all the things we need to survive and most people can’t imagine what it would be like to suddenly find there’s no water coming out of the taps and all the shops are shut or empty of goods.

  11. I thought the funniest one-liner was where Russell said that Tom Fuller made a typo and meant instead that Curry should be nominated for the NIPCC lead and not IPCC ….

    Is there really anything more depressing than Curry’s antics in all of climate science? See http://judithcurry.com/2015/03/05/2-new-papers-on-the-pause/

    Perhaps there is something wrong with the lack of a killer instinct regarding this “faux pause” argument. All the variability boils down to known variability in natural phenomena such as ENSO that anybody with any spreadsheet skills can work out:

    #WHUT is wrong with this picture?

  12. It seems like the Guardian’s editor has arrived at a similar point: http://www.theguardian.com/environment/2015/mar/06/climate-change-guardian-threat-to-earth-alan-rusbridger

    Let’s hope for a carefully measured analysis of possible impacts based firmly in the science, and not to many flights of fancy that are difficult to defend.

  13. ATTP wrote in the original post:

    “I’m never quite sure how best to respond to comments of the type – “okay, so temperatures will go up, sea levels will rise, oceans will acidify, ice will melt, precipitation patterns will change; so what?””

    The well known saying that everything is a matter of degree is very applicable here, since the “so what?” has the hidden assumption that the endgame degree in possibly 1 or 2 centuries probably won’t be enough to cause all that much harm. And so the discussion goes to the endgame degree.

    Have them read everything said by economist Martin Weitzman, now at Harvard – at least the material suitable for a wider audience, like his books, especially the most recent one:
    http://en.wikipedia.org/wiki/Martin_Weitzman#Books.

    The below is a start, which should be read with what Weitzman says on the Sherwood and Huber results, about the nontrivial probability that there will in 1 or 2 centuries simply be too much heat for humans to live in some or all of the tropics and subtropics, since by then it would have gone to the point where typical summertime afternoons will kill mammals. And of course it should be kept in mind that if this particular point is never reached, all the implied disasters could still happen from there being enough heat so that at least sufficient percentages of mammalian populations are killed by typical afternoon highs in the summer in these places. (This latter could happen with what, an endgame global increase of only 5 degrees C or perhaps even less? Very doable.) Humanity truly is playing Russian roulette, and is pulling the trigger more and more often as the emissions keep going up and up:

    “The Odds of Disaster: An Economist’s Warning on Global Warming”
    http://www.pbs.org/newshour/making-sense/the-odds-of-disaster-an-econom-1/

    Quote:

    “If we were to continue CO2 emissions to an atmospheric concentration of 800 ppm of CO2, the IPCC formula translates into an ultimate average temperature change of 4.5 C (8.2 F) with a likely range between 3 C (5.4 F) and 6.8 C (12.3 F). The world has not seen this level of CO2 concentrations for some 50 million years, when crocodiles and palm trees thrived in the Arctic Circle, Greenland and Antarctica were ice-free, and sea levels were hundreds of feet higher than today.
    ……
    No one can say with any assurance what would be the dollar value of damages from the highly uncertain climate changes that might accompany a planet earth warmed by an average of more than 3 C (5.4 F). Economists do their best, but such estimates are mostly wild extrapolations from lower temperatures, or are just plain made up.
    ……
    Relying on averages may be OK for small amounts of uncertainty. But climate change damages from high levels of greenhouse gas concentrations are enormously uncertain. In this kind of situation, for an economist, abating CO2 emissions is like buying insurance against a catastrophe. We should cut back on CO2 emissions not only to lower the average damages, but, perhaps more importantly, to lower the probability of catastrophic damages. That could imply a lot more CO2 emissions abatement than if we were concerned only about the most likely or average damages.
    ……
    The bottom line is that if we continue on a business-as-usual trajectory, then there is some non-trivial probability of a catastrophic climate outcome materializing at some future time. Prudence would seem to dictate taking action to cut back greenhouse gas emissions significantly. If we don’t start buying into this insurance policy soon, the human race could end up being very sorry should a future climate catastrophe rear its ugly head.”

  14. corey says:

    I vote for including a competent econometrician this time around.

  15. For most impact studies you need regionally or even locally reliable climate projections and often predictions. This has large uncertainties. As far as we can avoid it, I would personally prefer not to perform impact studies for every region (and for many details, e.g. for every agricultural crop). It would in this stage better to go into depth and really understand the tools we need and develop better tools.

    When it comes to downscaling there are already some larger initiatives to compare and understand the various methods. The last would be the COST Action (EU science network) VALUE. (Disclose I work a little on downscaling myself.) This would be something we could scale up to something similar to CMIP.

    How good global climate models model the regional climate could also be part of CMIP (if it is not already). There are so many CMIP nowadays, one more would not hurt.

    There is a proposal for a new CMIP on decadal climate prediction, which would be important for many impacts (investment decisions are to a large part for the next decades, not 2100 or even longer).

    The above is basically the input of the impact studies. The impact studies themselves may be harder to organize in such a way. Maybe it is possible to abstract part of these studies and in that way get the mass you need for such large-scale collaborative efforts.

  16. matt says:

    @WHT,

    Tom Fuller nominating Curry as chair… Oh dear.

    She just recently (in her 50-50 response) admitted she had been arguing against the IPCC position without even understanding it. Happy for her to be an author (although I think there are many more qualified candidates), but before she can be considered for a more senior role she needs to show she

    1) understands the existing literature, and
    2) can put some numbers in an analysis (rather than, “50-50 because… uncertainty monster”)

  17. -1=e^ipi says:

    The problem with most impact studies is the large amount of confirmation bias and distortion of incentives that affects them. These studies are far more likely to look at the damages and make doomsday predictions, because this is more likely to lead to more funding. One is more likely to get funding for ‘a study on tree frogs and the impact of climate change’ than for ‘a study on tree frogs’.

    @ Andrew Dodds –
    “the top 80% or so at least – have lived for decades in a situation where the basics of life – food, water, electricity, housing, physical security, disaster relief, etc – appear inviolable, as in ‘they just happen’, just as the air is always breathable,”

    I wish I was in this top 80%. It sounds sort of nice. Having always breathable air would be pleasant as well.

  18. -1,

    The problem with most impact studies is the large amount of confirmation bias and distortion of incentives that affects them. These studies are far more likely to look at the damages and make doomsday predictions, because this is more likely to lead to more funding. One is more likely to get funding for ‘a study on tree frogs and the impact of climate change’ than for ‘a study on tree frogs’.

    Sorry, but this is essentially defamatory (well, insulting to those doing this research). You may think it true, but if so you could either express it as an opinion or not express it at all (preferred option). If you really want to say such things, you should provide some fairly watertight evidence.

  19. Eli Rabett says:

    Even back in 2007, as Eli wrote, a large majority of papers in the literature dealt with the economic and biological consequences of global climate change showing the wide scientific consensus agreeing with the IPCC AR4.

    The reason WGI comes out first these days is it establishes the physical science basis for climate change. There is probably no way to rationally change this, although the Winter Olympics have indeed been moved to alternate with the Summer ones. You could do that the Bunny supposes, increase the delay btw WGI and WGII and WGIII, but it probably would not hurt to fold WGI at this point. After all the driving conclusions have not changed much since 1900.

  20. Willard says:

    > [Judy] just recently (in her 50-50 response) admitted she had been arguing against the IPCC position without even understanding it.

    Judge Judy went a bit beyond that:

    We need to put down the IPCC as soon as possible – not to protect the patient who seems to be thriving in its own little cocoon, but for the sake of the rest of us whom it is trying to infect with its disease.

    http://judithcurry.com/2013/09/28/ipcc-diagnosis-permanent-paradigm-paralysis/

    Promoting someone who’d put the whole process down has been seen before.

  21. -1=e^ipi says:

    @ ATTP – “Sorry, but this is essentially defamatory”

    How is it defamatory if I did not name anyone in particular?

    Also, how is it necessarily insulting. With respect to putting climate change in the title of a research proposal, many will be doing good and honest research but cannot get funding without it due to the political nature of many research grants. They are just playing the game. It’s not just climate change either. In my graduate studies in physics, I was told frequently by many professors that to get funding you need to put in buzz words like ‘nano’, even if it didn’t make sense from a scientific standpoint.

  22. Lucifer says:

    I saw where a fossil find pushed back the date of the earliest Homo Habilis to about 2.4 million years ago. That means human ( and most other species ) evolution has endured scores of cold glacials and hot interglacials.

    Its difficult for me to understand the panic.

  23. BBD says:

    One is more likely to get funding for ‘a study on tree frogs and the impact of climate change’ than for ‘a study on tree frogs’.

    An almost exact quote from The Great Global Warming Swindle. Now for bonus points, who said it, and which animal did (s)he use as an example?

    🙂

  24. -1,

    How is it defamatory if I did not name anyone in particular?

    True, but I’m not really interested in such comments. I can’t see any value in them and I can’t see much point in posting them. Also, you didn’t just imply that they would make things sound more interesting than might be warranted, you specifically said make doomsday predictions, because this is more likely to lead to more funding which would imply an element of fraud or research misconduct.

    Look, I’m just not interested in such comments. You don’t have to trust the research. You can hold whatever view you might like, but unless you can back them up with some actual evidence, I’d really rather you didn’t post such views here, especially if you don’t even bother to make it clear that it’s your opinion, rather some self-evident truth.

  25. Lucifer,

    I saw where a fossil find pushed back the date of the earliest Homo Habilis to about 2.4 million years ago. That means human ( and most other species ) evolution has endured scores of cold glacials and hot interglacials.

    Its difficult for me to understand the panic.

    Firstly, panic is your word. Secondly, if there is any panic it’s not about the survival of the species, life in general, or the planet. If you think that a population numbering in the millions, surviving changes from glacials to interglacials somehow means that a population of billions can survive unaffected by a similar temperature change today, then I don’t think you’re quite giving this quite enough thought.

  26. BBD says:

    Agriculture was only invented in the Holocene, Lucifer.

  27. BBD says:

    IIRC what the daft woman actually said was ‘brioche’…

    🙂

  28. Michael 2 says:

    Lucifer says: (March 6, 2015 at 6:22 pm) “human ( and most other species ) evolution has endured scores of cold glacials and hot interglacials. Its difficult for me to understand the panic.”

    Playing warmist advocate for a moment — everything that constitutes “society” has happened in the present interglacial. The next glacial could find survivors closely resembling modern Inuit, not that it is such a bad thing to be especially if you are born into it and that’s all you know.

    But the worst will be the population selection process choosing the survivors.

  29. sullis02 says:

    Lucifer: “I saw where a fossil find pushed back the date of the earliest Homo Habilis to about 2.4 million years ago. That means human ( and most other species ) evolution has endured scores of cold glacials and hot interglacials.

    Its difficult for me to understand the panic.”

    LOL, you cannot be serious. If you are I’ll make sure not to bother reading your posts henceforth. “Endured” is a key word indeed. And btw, so is ‘panic’, and yeah, we see what you did there.

  30. One is more likely to get funding for ‘a study on tree frogs and the impact of climate change’ than for ‘a study on tree frogs’.

    I would say this is true. There are many scientists that add a little climate change to their proposals to make them look nicer. And then mostly do the work they had wanted to do anyway.

    The suggestion that these scientists let that influence the *results* of their studies, not just the choice of topic is the part I do not believe for most scientists. And in mature fields that can not happen.

    The best way to get attention to your work is to find that the tree frogs will do better due to climate change. Just like the best route to fame is to attack the IPCC.

    It is a tribute to the high moral values in the scientific community that almost no one is willing to say such things. (Maybe also for the bad working conditions that make that only people with an enormous drive to understand the world chose to become scientist.)

  31. verytallguy says:

    Lucifer, it’s the rate , stupid

  32. BBD says:

    vtg

    Yeah but she might have been quoting Rousseau 😉

  33. Michael 2 says:

    ATTP “I’m never quite sure how best to respond to comments of the type – okay, so temperatures will go up, sea levels will rise, oceans will acidify, ice will melt, precipitation patterns will change; so what?”

    I propose there is no single best answer and that’s why no published document is going to be particularly successful. The “temporal window” of consideration, how far into the past and how far into the future, relates. A person that does not consider past or future (most teenagers it seems to me) doesn’t care, cannot care, about at thing that’s predicted to take a thousand years anyway.

    The typical duration of a democracy is considerably shorter than the imminence of doom.

    http://www.stier.net/writing/demstab/stability.htm

    I suggest that people that actually fear climate change have internalized a distant-future hypothetical situation; activating the limbic system and mirror neurons, and thus react exactly as if the danger were immediate and present, when in fact it isn’t (in most cases). Occasionally a danger presents itself that, at its margins, might have something to do with “climate change”; such as the flooding in Minnesota a few years ago. But while the climate has been changing since “forever”, persuading that farmer in Minnesota that all he needs to do is pay double for fuel for his tractors and that the change will stop changing; well that might be a tough sell.

    Persons living in Washington DC are living with actual danger real, immediate and present (danger of being robbed, shot, or just losing your job and home). The possibility of DC being under water in a few hundred years is less a concern than the probability that there won’t be a Washington DC in 200 years anyway.

    Oil will run out long before Greenland’s ice cap melts.

    A meaningful goal is, and has always been, alternative energy sources. For Americans since at least the 1973 oil embargo energy independance is a more persuasive “meme” than worrying about polar bears.

  34. -1=e^ipi says:

    @ ATTP –
    “because this is more likely to lead to more funding which would imply an element of fraud or research misconduct.”

    Well there is scientific fraud and misconduct in many areas of research. I’ve seen it first hand in fields of study that are not politicized at all. I don’t mind going into details in private, but in public is another matter.

    Anyway, you do not wish to discuss the issue of fraud, distorted incentives, dogmatism, etc. so I will respect your wish. Although I thought it was related to what Judith Curry was discussing. Can I at least ask you this? What does ‘science’ mean to you? Is it a methodology, a subject, a collection of facts, or an institution?

  35. -1,

    Can I at least ask you this? What does ‘science’ mean to you? Is it a methodology, a subject, a collection of facts, or an institution?

    I’m not sure there’s a trivial answer, but I would probably regard it more as a methodology than anything else.

  36. Willard says:

    > Also, how is it necessarily insulting.

    It only needs to be insulting. Very little speech acts are necessarily something.

    You’re not going to pretend “but it was only descriptive,” do you?

    Then, let’s see: many contrarian comments we read at AT’s lately display machiavellianism.

    Just a description, you know. Not targetting anyone in particular.

  37. BBD says:

    More word placement games from -1. Ho-hum.

  38. Michael 2 says:

    “What does ‘science’ mean to you? Is it a methodology, a subject, a collection of facts, or an institution?”

    It is a method for knowing things and the things that are known.

    It may happen that you first know a thing and wish to find out how it came to be; knowledge precedes method.

    Or you may engage in a method and produce a discovery; method precedes knowledge.

    Science can also disprove something; if the method is correct and fails to yield a predicted result, the claim is falsified. Of course, that just shifts the burden to ensure the method is correct which becomes simply another round of scientific effort.

  39. Eli Rabett says:

    M2 said

    Persons living in Washington DC are living with actual danger real, immediate and present (danger of being robbed, shot, or just losing your job and home). The possibility of DC being under water in a few hundred years is less a concern than the probability that there won’t be a Washington DC in 200 years anyway.

    Bunnies who look at a map would see that Washington DC is a lot of kilometers away from the sea on a tidal estuary called the Potomac. Moreover as a bunny who lives in Washington DC, allow Eli to point out that the major present danger is idiot right wing Republican assholes like Rep. Andy Harris, who think they own the place. Crime is much down, and never was as bad as you saw on the nightly news.

    However, bunnies living in Norfolk, a Virgina city down by the ocean, have sea level rise and climate change on their minds big time. Which is amusing because a lot of them are Inhofians

  40. Brandon Gates says:

    -1=e^ipi,

    Well there is scientific fraud and misconduct in many areas of research.

    Then for consistency’s (and pity’s) sake, reject all science, give up the trappings of modern life the practice and institution of science has given you with its entire corpus of inferred conclusions and go live off the grid in a grass hut so as to not further the rampant corruption with your tax monies.

    — OR —

    Do what honest, rational, proper sceptics do: evaluate specific claims and if you find something questionable, raise the point with a citation and propose a debate of the particular issue on its merits or lack thereof. The best evidence in a debate is that which is clearly written down in black and white and freely accessible to all for their own independent review and evaluation, not personal supposition of others’ motives, agendas and/or malfeasance by way of sweeping generalizations implied by vague references to anecdote of wrongdoing in wholly unrelated fields.

    Plausibility of misconduct by monetary corruption is not a priori evidence of it. If you want to play that game, there are lorry loads of industry-funded scientists doing climate research who can be (and have been) tarred with the same broad brush. The financial motive “argument” is zero-sum: everyone needs to eat, and most of us do that by doing work and getting paid.

  41. Joshua says:

    -1

    ==> “These studies are far more likely to look at the damages and make doomsday predictions, because this is more likely to lead to more funding.”

    Do you reject Soon’s work? If not, why not?

  42. Joshua says:

    -1

    ==> “The problem with most impact studies is the large amount of confirmation bias and distortion of incentives that affects them.”

    Do you reject the work of Lewis, Curry, Christy, and Spencer? If not, why not?

  43. Brandon Gates says:

    ATTP,

    Your post is timely because these issues have been topical for me elsewhere. By way of answering “where does all this stuff live?” I offer you some tidbits gleaned from my own recent readings.

    From TAR WGII, specific to Australia:

    http://www.ipcc.ch/ipccreports/tar/wg2/index.php?idp=484

    12.8. Adaptation Potential and Vulnerability 12.8.1. Adaptation and Possible Benefits of Climate Change

    It has not been assumed that all the impacts of climate change will be detrimental. Indeed, several studies have looked at possible benefits. Moreover, adaptation is a means of maximizing such gains as well as minimizing potential losses.

    However, it must be said that potential gains have not been well documented, in part because of lack of stakeholder concern in such cases and consequent lack of special funding. Examples that have not been fully documented include the possible spread of tropical and subtropical horticulture further poleward (but see some New Zealand studies, on kiwi fruit, for example—Salinger and Kenny, 1995; Hall and McPherson, 1997b). In southern parts of Australia and New Zealand, notably Tasmania, there could be gains for the wine industry, increased comfort indices and thus tourism, and in some scenarios increased water for hydroelectric power generation.

    Taken at face value, the IPCC are saying that more complete analysis of future beneficial impacts due to warming, CO2-enrichment, etc., is limited by local and regional stakeholder concerns. IOW, “we’d like to do a better job in our CBAs of estimating benefits, but we find that the bulk of quality research and funding has gone toward assessing negative impacts, not positive.” Which I think is perfectly understandable as well as quite defensible from a research allocation perspective — better to be surprised by an unforeseen upside than an unanticipated downside.

    From AR5 WGII, a rather nice summary of the inherent difficulties in modelling past performance and projecting the future:

    http://www.ipcc.ch/pdf/assessment-report/ar5/wg2/WGIIAR5-Chap7_FINAL.pdf

    7.2.1.1. Crop Production

    Many studies of cropping systems have estimated impacts of observed climate changes on crop yields over the past half century, although they typically do not attempt to compare observed yields to a counterfactual baseline, and thus are not formal detection and attribution studies. These studies employ both mechanistic and statistical approaches (Section 7.3.1), and estimate impacts by running the models with observed historical climate and then computing trends in modeled outcomes. Based on these studies, there is medium confidence that climate trends have negatively affected wheat and maize production for many regions (Figure 7-2) (medium evidence, high agreement). Because many of these regional studies are for major producers, and a global study (Lobell et al., 2011a) estimated negative impacts on these crops, there is also medium confidence for negative impacts on global aggregate production of wheat and maize. Effects on rice and soybean yields have been small in major production regions and globally (Figure 7-2) (medium evidence, high agreement). There is also high confidence that warming has benefitted crop production in some high-latitude regions, such as northeast China or the UK (Jaggard et al., 2007; Chen et al., 2010; Supit et al., 2010; Gregory and Marshall, 2012). More difficult to quantify with models is the impact of very extreme events on cropping systems, as by definition these occur very rarely and models cannot be adequately calibrated and tested. Table 18-3 lists some notable extremes over the past decade, and the impacts on cropping systems. Despite the difficulty of modeling the impacts of these events, they clearly have sizable impacts (Sanchez et al. 2014) that are apparent immediately or soon after the event, and therefore not easily confused with effects of more slowly moving factors. For a subset of these events, climate research has evaluated whether anthropogenic activity has increased or decreased their likelihood (Table 18-3).

    I find that succinct quantification at a high-level is difficult to come by so I empathize with the fog you find yourself in. Best I’ve got at the moment is this, from the first pages of the same document:

    Executive Summary

    The effects of climate change on crop and terrestrial food production are evident in several regions of the world (high confidence). Negative impacts of climate trends have been more common than positive ones. {Figures 7-2, 7-7} Positive trends are evident in some high latitude regions (high confidence).

    From there the document jumps right into the weeds and overwhelms (me) with so much information that, at present, I could not give anyone a one-paragraph answer comparing the net present value of mitigating vs. not mitigating or, by RCP, anywhere in between. Anyone who could point me to a middling-level detail monetized estimate from the IPCC would be thanked for steering me in that direction. I have recently read this document from the EPA …

    http://www2.epa.gov/sites/production/files/2014-06/documents/20140602ria-clean-power-plan.pdf

    … p ES-21 (p 46 of the .pdf) of which contains the following table along the lines of what I’m looking for: Table ES-8. Summary of Estimated Monetized Benefits, Compliance Costs, and Net Benefits for the Proposed Guidelines – 2020 (billions of 2011$)

    If I’m understanding it correctly, compliance costs range from $4.3-7.4 billion/year, estimated net benefits from $20-50 billion per year. I believe that the compliance costs are US-only and net benefits are calculated as the worldwide positive impacts of a US-only mitigation scheme.

  44. “There is not such a formal position endorsed by the IAU. Let alone any claim from IAU [International Astronomical Union] that suggests that global warming (defined as the heating trend observed on Earth during the last mid 20th century) can be explained by solar variability.”

    While it is clear that the Sun does have an impact on Earth’s climate and that changes (over the past few centuries) have been tentatively ascribed to solar irradiance changes, there is a common consensus by the solar community that the recently observed warming trend cannot be related to changes on the Sun.

    As a consequence of these contacts, the OC of Division II has decided to create a group of experts from Commissions 10 and 12 to issue a brief, strictly scientific, report on the status of our understanding of solar influences on Earth’s climate, with specific focus on the changes observed in the past century, where the consensus is clear. Once a formal resolution is received from this group of experts and discussed in the Division II OC, it will be elevated to the IAU Executive for their evaluation.”

    Valentin Martínez Pillet (President, IAU Division II, Sun and Heliosphere July 2012)

    Hmmm, I guess the IAU would get more funding when they would claim that global warming is due to changes in the sun. Why they hell would they write something like that?

  45. Lucifer says:

    “Agriculture was only invented in the Holocene, Lucifer.”

    Yes, largely during the Altithermal.

  46. Lucifer says:

    “However, bunnies living in Norfolk, a Virgina city down by the ocean, have sea level rise and climate change on their minds big time.”

    Most buildings today are not a hundred years old. Why?
    Because we tear them down when they get old.

    Worrying about 3 mm a year rise flooding buildings is silly when
    no one 500 years from now will want your smelly old coastal buildings.

  47. Brandon Gates says:

    Dr. Betts,

    Having been a lead author in WG1 in AR4 and then WG2 in AR5, I can confirm that the latter was a harder job!

    That conforms to my lay outsider’s sense of things, your confirmation is appreciated. It should go without saying that your personal and collective efforts are as well.

    So a key question is, should the ‘impacts community’ try to coordinate itself more and do ‘big science’ like the climate modelling community?

    That sounds right not least because it appeals to parity and symmetry which I think looks inherently more internally AND externally coordinated. Again I speak as a member of the public thinking far more in terms of PR.

    While you’re here I do have a request for consideration along the lines of how impacts are communicated. By RCP, I’d very much like to see a one-page summary on the first page of an impact report in tabluar form. The columns being the “best estimates” of:

    – Cost of mitigation
    – Benefits (and co-benefits) of mitigation

    – Cost of impacts
    – Benefits of impacts

    – % of present global GDP for all the above

    After that, detailed drilldowns as appropriate, but in the same tabular format so that the whole picture is always on the same page, or at least consecutive pages.

    Then the ranges and other statistics of the estimates, detailed definitions, assumptions, caveats, supporting documentation and narratives. Apologies in advance if I ask for something which does already exist in similar form.

  48. BBD says:

    @ Richard Betts

    You were a co-author of Gornall et al. (2010) Implications of climate change for agricultural productivity in the early twenty-first century:

    This paper reviews recent literature concerning a wide range of processes through which climate change could potentially impact global-scale agricultural productivity, and presents projections of changes in relevant meteorological, hydrological and plant physiological quantities from a climate model ensemble to illustrate key areas of uncertainty. Few global-scale assessments have been carried out, and these are limited in their ability to capture the uncertainty in climate projections, and omit potentially important aspects such as extreme events and changes in pests and diseases. There is a lack of clarity on how climate change impacts on drought are best quantified from an agricultural perspective, with different metrics giving very different impressions of future risk. The dependence of some regional agriculture on remote rainfall, snowmelt and glaciers adds to the complexity. Indirect impacts via sea-level rise, storms and diseases have not been quantified. Perhaps most seriously, there is high uncertainty in the extent to which the direct effects of CO2 rise on plant physiology will interact with climate change in affecting productivity. At present, the aggregate impacts of climate change on global-scale agricultural productivity cannot be reliably quantified.

    If you see this comment, I would be very grateful if you would indicate if expert opinion has altered since this paper was published and briefly summarise any key developments.

  49. -1=e^ipi says:

    @ Brandon Gates –

    “Then for consistency’s (and pity’s) sake, reject all science, give up the trappings of modern life”

    How is that consistent? Science isn’t an institution, it is a methodology. And I follow the scientific method, I do not reject it. Individuals that approach the issue of climate change dogmatically for the sake of saving the word… well they don’t follow the scientific method (like say the former chair of the IPPC, Pachauri, who claims that “For me the protection of Planet Earth, the survival of all species and sustainability of our ecosystems is more than a mission. It is my religion and my dharma.”). The existence of individual scientists committing fraud or misconduct does not invalidate the scientific method, nor does it invalidate the majority of scientific results.

    @ Joshua –

    “Do you reject Soon’s work? If not, why not?
    Do you reject the work of Lewis, Curry, Christy, and Spencer? If not, why not?”

    For the vast majority of work by these individuals, I have not read it so I can neither accept nor reject it. I have read a bit of the work by Lewis and Curry. It is okay, but the model used to describe reality isn’t the greatest, so I wouldn’t put too much weight on the results (model specification error is likely to bias the resulting estimates).

  50. Brandon Gates says:

    Victor,

    Why they hell would they write something like that?

    Because CO2 is the desired enemy and ruling out the Sun allows the IPCC world takeover charlatans to further their nefarious goal of sending all of humanity but themselves back to the Stone Age.

  51. Tom Curtis says:

    -1=e^ipi,

    “How is it defamatory if I did not name anyone in particular?”

    Nor did you exempt anyone, so therefore you have defamed all who have done studies looking at impacts.

    The only acceptable defense when you make such defamatory comments is to provide the evidence. Absent evidence, the content of your remark comes down to “I do not like their results, so therefore I will use an unjustified (by evidence) defamation to avoid accepting them”. My opinion of you is marked down accordingly.

  52. Tom Curtis says:

    Lucifer:

    “I saw where a fossil find pushed back the date of the earliest Homo Habilis to about 2.4 million years ago. That means human ( and most other species ) evolution has endured scores of cold glacials and hot interglacials.”

    I believe you will find that in none of the previous glacial to interglacial switches did any of the people finding a necessity to migrate into already populated lands because their land was less verdant (or under water) had nukes. Some may consider that a relevant difference.

  53. Tom Curtis says:

    -1=e^ipi

    “Can I at least ask you this? What does ‘science’ mean to you? Is it a methodology, a subject, a collection of facts, or an institution?”

    That is a false trichotomy. Specifically, science as a method requires the acceptance of certain facts to proceed further. Unless, for instance, you accept Newton’s laws of optics, you have no basis to accept Galileo’s observational astronomy. Further, a subject is just (in this context) a collection of methods, and basic facts in a particular field. Therefore any attempt to say that science is a method and not a collection of facts and a subject as well is self defeating. It necessarily excludes the possibility of there being scientific knowledge, or even scientific findings.

    Further, the methods of science are not reducible to being variations of any one single method. That follows as a simple matter of sociology in that scientists of different eras (and even in the same era) have disagreed as to what the supposed universal method of science is. Consequently they have modified their methods in practice accordingly. However, the fact that Darwin applied the scientific method as conceived at his time (actually two methods, that of vera causa and that of conciliance of inductions) does not make his work any less scientific than that of the positivists (such as Einstein) of the falsificationists.

  54. izen says:

    @–1
    “What does ‘science’ mean to you? Is it a methodology, a subject, a collection of facts, or an institution?”

    It is all 4 things operating synergistically.
    But more to the point, it is the communal activity of human societies with the most utile outcomes.

  55. Well, while I’m waiting for the groundswell of opinion to carry Judith Curry to victory, I’ll add a quick comment about impacts.

    One of the greatest difficulty in assessing impacts is divorcing conventional economics from such assessments. Once you are trying to measure how much GDP will be lost, or what discount rate should be applied to future values, the game is lost. Stern basically will not stand the test of time because of such things. His paper would have needed to be 6,000 pages instead of 600 to really do a good job of it.

    Tol et al may have got their numbers wrong in a study showing 0.26% of land would be lost due to a 1-meter rise in sea level, but at least they were measuring the right thing. The Dartmouth Flood Observatory needs a lot of work for attribution of increased floods to climate change (they base their data on news reports, which have increased as more countries make and report news) but at least they are looking at incidence, damages and deaths.

    Because mitigation and adaptation efforts will very quickly change the economic calculus, economics is not well-equipped to assist us in measuring impacts. If we focus on the physical then we at least provide tools to help planners. It will remain difficult for as long as models are unable to resolve projections to a regional (and sub-regional) level. But even so, impact evaluations should be aiming at providing physical data.

  56. thomas,
    Having seen your behaviour elsewhere, I almost deleted your comment. I won’t put up with what appears to be your typical nastiness. I also think that you’re immediately including economic value, which isn’t always necessary. It is possible to estimate the impact of some change without necessarily relating that to economics. Of course, at the end of the day, we’re essentially interested in how this will impact our lifestyles and standards of living, but that doesn’t immediately mean that impacts should be thought of as solely economic.

  57. Rachel M said on March 6, 2015 at 11:33 am:
    “I would like to see more written about the impacts of climate change too and not just from a very abstract and unemotional scientific viewpoint but on a more personal level.”

    In the spirit of replying to this, I will reiterate a personal experience I shared before: On a very hot summer day in Florida in the late 1990s, I experienced something I’ve not experience before or since, and it does make me concerned for the future of human civilization. The mechanism of evaporative cooling was so “short-circuited” by such a high combination of heat and humidity, the air from the fan did not cool at all (it always cooled before and since). It instead felt like a blow-dryer blowing superheated air onto my skin. (I had to go back inside to the air conditioning. A power failure would have been bad news.) I believe that I was getting a taste of wet bulb temperatures moving enough in the direction of those described by Sherwood and Huber (2010) to make me concerned for my physical well-being had I not had a micro-environment to retreat into. As I’ve explained before, the hell on Earth they warn about could come more easily and quickly than many realize. I go into this more below.

    Michael 2 said on March 6, 2015 at 7:41 pm:
    “I suggest that people that actually fear climate change have internalized a distant-future hypothetical situation…..”

    It’s not distant-future and it’s not merely hypothetical – it’s a very real game that is similar to Russian roulette whose end of game can occur over the next one or two centuries, not a thousand years as you keep saying.

    “But while the climate has been changing since “forever”….”

    This “climate has been changing since “forever”” is false in terms of what *modern* mammals may experience in a century or two, which is heat and humidity that they have not experienced over the course of their entire evolution for millions of years (typical summertime afternoon heat indexes in parts of the tropics and subtropics approaching 200 degrees F), not seen naturally for about 50 million years.

    And no more rot about how bad it would be if the countries of the world got together and agreed to do climate change mitigation by agreeing that it is unacceptable that millions of people die from air pollution each year (1.2 million in China and 600,000 in India each year), and in the name of saving many, many millions of future lives, this obscenity of so many dying so needlessly must be dealt with in no uncertain way and with urgency.

    This would especially be about very dirty electricity generation – recall my citation showing that 2000 die each year to keep the lights on in Beijing while only 200 die each year to keep the lights on in New York City. And this, even though it may be the case that New York City uses twice as much electricity as Beijing. That’s a 20-fold difference, and it seems to reflect the fact that air quality in Beijing is about 20 times worse than in New York City. This is just the tip the iceberg that shows that it is simply false that the world – China and India especially – has had to burn such high amounts of the dirtiest coal in the dirtiest ways. (And, by the way, the dirty burning of dirty coal is responsible for a large percentage of all that toxic mercury in our fish dinners from the world’s oceans and lakes and rivers – bon appetit. See
    http://en.wikipedia.org/wiki/Mercury_in_fish
    for more. Quote: “Much (an estimated 40%) of the mercury that eventually finds its way into fish originates with coal-burning power plants and chlorine production plants.[25]”)

    -1=e^ipi said on March 6, 2015 at 5:14 pm:
    “The problem with most impact studies is the large amount of confirmation bias and distortion of incentives that affects them. These studies are far more likely to look at the damages and make doomsday predictions, because this is more likely to lead to more funding.”

    If you have an actual argument to make against Sherwood and Huber (2010) that actually can hold up under critical analysis, then let’s see it.

    …and Then There’s Physics said on March 6, 2015 at 6:43 pm:
    “Lucifer,
    “I saw where a fossil find pushed back the date of the earliest Homo Habilis to about 2.4 million years ago. That means human ( and most other species ) evolution has endured scores of cold glacials and hot interglacials.”

    If you think that a population numbering in the millions, surviving changes from glacials to interglacials somehow means that a population of billions can survive unaffected by a similar temperature change today, then I don’t think you’re quite giving this quite enough thought.”

    And this similar change in question would be in the wrong direction, one that could send human beings and all of *modern* mammals into a world that they have not seen during their entire evolution of many millions of years. Per Sherwood and Huber, this could be a world of wet bulb temperatures not seen naturally on Earth for roughly 50 million years and high enough to kill off entire populations of mammals (of course including humans) in the tropics and subtropics in a single summer afternoon (roughly 35 degrees C, wet bulb, which gives heat indexes approaching 200 degrees F). They think this would happen with a 7 degree C increase in global temperature. Or, by how they defined some variables (I explained this before), it could be less, a world of wet bulb temperatures high enough to kill off sufficient percentages of mammalian populations each summer to make such populations in such areas nonviable. Again, we would get to the latter much sooner than the former and since the former is quite doable with a continuation of the present high emissions path, with all the more force the latter is that much more doable, and this could happen with a less and even much less than a 7 degree C increase in global temperature.

    Tom Curtis said on March 7, 2015 at 1:55 am, also in reply to the above by Lucifer:

    “I believe you will find that in none of the previous glacial to interglacial switches did any of the people finding a necessity to migrate into already populated lands because their land was less verdant (or under water) had nukes. Some may consider that a relevant difference.”

    Thank-you. I’ve been pushing this point in a number of comments. The naysayers forget.

    In addition, Lucifer did not address the fact that these “hot” interglacials were a joke compared to the heat and humidity described above (typical summertime afternoon heat indexes in parts of the tropics and subtropics approaching 200 degrees F) that many of the world’s mammals may very well get to experience in the next one or two centuries. (Thanks, humanity.) First, one needs to consider the probability of the world will experiencing enough of a heat increase to get to these wet bulb temperatures that would be high enough to kill off a sufficient percentage of the human and other mammalian populations in parts of the tropics and subtropics each summer to make human civilization and mammalian populations in general nonviable in these areas, which (as I’ve explained before by how Sherwood and Huber defined some of their variables) can occur with global temperature increases of less and perhaps significantly less than a 7 degree C increase. Then this begs the question of how much it raises the probability of nuclear war that might not otherwise occur between some of those that need to migrate to cooler climates to survive and some of those who hold the land to which the former need to migrate.

  58. Eli Rabett says:

    lucifer mentioned

    “Most buildings today are not a hundred years old. Why?
    Because we tear them down when they get old.”

    That’s what they said in Venice. Many of the flood zones in Hampton Roads (the area of Virginia where Norfolk is) are in the oldest parts of towns because that is where it was easiest to land boats. This is why the 0.26% of the land that Fuller channels Tol’s blather about is about as telling as the CO2 is only 0.040% of the atmosphere so how can it do anything trope that gets hauled out. Within that small percentage is much of the most valuable and populated land we got.

  59. Brandon Gates says:

    -1=e^ipi,

    The existence of individual scientists committing fraud or misconduct does not invalidate the scientific method, nor does it invalidate the majority of scientific results.

    I’m glad we got that established, I very much agree.

    Individuals that approach the issue of climate change dogmatically for the sake of saving the word… well they don’t follow the scientific method (like say the former chair of the IPPC, Pachauri, who claims that “For me the protection of Planet Earth, the survival of all species and sustainability of our ecosystems is more than a mission. It is my religion and my dharma.”)

    And ___________________________ ?

  60. Willard says:

    > Individuals that approach the issue of climate change dogmatically for the sake of saving the word…

    To speak of stewardship might be more appropriate:

    Our Mission

    We seek to magnify the glory of God in creation, the wisdom of His truth in environmental stewardship, the kindness of His mercy in lifting the needy out of poverty, and the wonders of His grace in the gospel of Jesus Christ.

    http://www.cornwallalliance.org/about/what-drives-us/

    Does it mean no scientist should participate in the Cornwall Alliance’s activity?

    Does it mean the Cornwall Alliance can’t provide any scientific input whatsoever?

  61. And Then There’s Physics, you write: “I also think that you’re immediately including economic value, which isn’t always necessary.”

    But that is in response to my comment, “One of the greatest difficulty in assessing impacts is divorcing conventional economics from such assessments. Once you are trying to measure how much GDP will be lost, or what discount rate should be applied to future values, the game is lost.”

    At the risk of sounding… nasty… do you always invert the meaning of what commenters write?

  62. Kevin ONeill says:

    TF is, of course, playing the game of trying to downplay any possible impacts. He has, for instance, written, ““The total number of refugees has risen, but they are pretty clearly conflict refugees, not climate victims” Whereas it is believed that climate change will increase conflicts, see Syria and drought. He offers a false dichotomy solely to minimize impacts.

    Likewise he equates Antarctic sea ice increases as somehow offsetting Arctic sea ice losses – even though the *impacts* of the two are vastly different.

    It’s a fool’s game and he’s been playing it a long time.

  63. BBD says:

    The thing about credibility, Tom, is that when it’s gone, it’s gone.

  64. Tom,

    At the risk of sounding… nasty… do you always invert the meaning of what commenters write?

    No, Tom – the “I think” at the beginning of my response was there for a reason. You could always respond in a manner that provided clarity, rather than in a manner that further confirms my first impressions.

    But even so, impact evaluations should be aiming at providing physical data.

    Yes, I broadly agree and this is what I had largely understood by the term “impact” in this context. I’m not quite sure I get the point of your comment, then, since my argument wasn’t for more modelling of economic impacts, but for a better understanding of the physical impacts.

  65. Lucifer says:

    That’s what they said in Venice. Many of the flood zones in Hampton Roads (the area of Virginia where Norfolk is) are in the oldest parts of towns because that is where it was easiest to land boats.

    The continents are ringed with the submerged office buildings of the day from past civilizations.
    Ours will be no different. But at a few inches a century, you will be long gone and no one at that time will care.

  66. Lucifer,

    Ours will be no different. But at a few inches a century, you will be long gone and no one at that time will care.

    You do understand the concept of acceleration? The IPCC projections suggest as much as 1m by 2100 under a high-emission pathway. Many people think these are too conservative.

  67. Pingback: Impacts | …and Then There's Physics

  68. Joshua says:

    Heh.

    =>> “At the risk of sounding… nasty… ”

    ‘Cause if there’s one thing we know about Tom, it’s that he tries to avoid the risk of sounding…nasty…

    ” The Klimate Konsensus is underhanded, goes for cheap shots and never admits error. They slime scientists on the other side. They insist that those in opposition are funded by fossil fuel interests. When that is shown not to be true, they change the argument and say opponents are using tactics and strategies stolen from the tobacco wars..”

    See! He uses k’s instead of c’s to avoid being…nasty…

  69. izen says:

    @-Lucifer
    “The continents are ringed with the submerged office buildings of the day from past civilizations.”

    Actually, they are not.
    One of the reasons we know that global sea level has been stable for most of the Holocene, and only started rising, at an accelerating rate, recently is because we can compare the sea level as recorded by past civilisations and see the difference. For instance Roman fish ponds. –
    http://people.rses.anu.edu.au/lambeck_k/pdf/242.pdf

    The other reason we know about Holocene sea level stability and the recent rise is because ancient civilisations had a penchant for recording lunar eclipses.

    While the USA is an outlier in this regard, most of the worlds largest cities are much older than a hundred years and most of their major civic buildings, infrastructure, roads, sewage systems, subways etc are much h older and are susceptible to sea level rise because most of the worlds biggest cities are coastal ports.

    @-““Agriculture was only invented in the Holocene, Lucifer.”
    Yes, largely during the Altithermal.”

    Actually, wrong.
    I presume the reference to the Altithermal was to imply that it was the higher temperatures, comparable with the present, that help, enabled or in some way was a factor in the invention of agriculture.
    The trouble is that the genetic evidence from domesticated crops indicates a much earlier start to agriculture in the fertile crescent and N Africa. Possibly pre-dating the LGM. There is clear archaeological evidence of agriculture before the younger Dryas. The Altithermal enabled an existing development to spread out to the warming Northern areas of the Eurasian continent.

    Agriculture in China, Papua New Guinea and the Americas had different start dates, but as the temperature peak in the Altithermal was a local effect with little evidence of major changes in the tropics or the Southern hemisphere it is more likely that it was rainfall changes that promted the development of agriculture in other areas as foraging became less reliable.

  70. BBD says:

    Izen

    The trouble is that the genetic evidence from domesticated crops indicates a much earlier start to agriculture in the fertile crescent and N Africa. Possibly pre-dating the LGM.

    Is there a reference for this? I ask as my understanding is that agriculture emerged within the Natufian culture eg. p. 53 of the 2004 edition of Steven Mithen’s After the Ice: A Global Human History 20,000 – 5000BC.

    Grains of rye excavated at Abu Hureyra dated to between 11,000 – 10,500BCE were “the oldest domesticated cereal grain from anywhere in the world” (but this was over a decade ago, so I may very well be out of date).

  71. guthrie says:

    I do wonder which country Lucifer is in. The UK has many, many buildings that are over 100 years old, and doesn’t tear them down simply because they are old. Tearing them down because someone can make money from the land is what actually happens, which is a different reason. Other countries had some unfortunate collisions with high explosives. Then there’s the interesting question of whether or not we have the resources to rebuild all the buildings every few decades.

  72. John Hartz says:

    My apologies if the article cited below has been referenced already but I haven’t had the time to particapte in this comment thread before now and I haven’t carefully read the commentary that has been posted to date.

    Directly related to the OP…

    Voluntary work alone cannot sustain the assessments carried out by the Intergovernmental Panel on Climate Change. Thomas F. Stocker and Gian-Kasper Plattner call for institutional support and a longer report cycle.

    Climate policy: Rethink IPCC reports, Thomas F. Stocker& Gian-Kasper Plattner, Nature, Sep 10, 2014

  73. Rob Nicholls says:

    This post (and the next one – ‘Impacts’) resonated with me (although I’m an amateur when it comes to physics and all the other disciplines brought together by the IPCC). The impacts are kind of the whole point (in terms of why this stuff matters, I mean) , so I’ve often wondered why I’ve spent so much time reading about WG1 physical basis stuff, and never seem to get around to delving into the details of impacts (beyond reading the summaries of IPCC WG2 and going into bits of the detailed chapters). (I think it’s mainly because the relative certainty of the physical science basis makes it seem slightly easier to get my head around, and because I can’t seem to tear myself away from the bizarre internet spectacle of watching what seem to be highly intelligent people rejecting evidence that seems to be so strong…these are not good reasons at all.)

    I’ve never really sought out a WG2 equivalent of Realclimate or ATTP or skeptical science (which mainly tend to focus on WG1), although I’ve thought of doing so. (Any weblinks would be much appreciated).

    I was really interested to read Richard Betts’s comment. A lead author in both WG1 and WG2 must surely have a very rare insight into the different approaches.

    In the parts of AR4 and AR5 WG2 that I’ve read, a lower level of coordination of research in WG2 compared to WG1 does seem apparent and I think it makes it harder for the reader to develop a mental picture of the overall evidence (I can’t imagine how hard writing these reports must be!) FWIW I think the ISI-MIP approach is good; more coordination of research efforts into climate change impacts might make it easier to communicate a summary of the evidence to non-experts (particularly journalists; you’d hope they at least would read IPCC reports if they’re reporting on them).

    From my position of almost total ignorance, modelling impacts on complex systems such as ecosystems and agricultural systems seems very difficult indeed, to the extent that I wonder whether it’s possible to constrain, say, the level of species loss which is likely to occur due to, say, 3 or 4 or 5 degrees C of global warming over the next century . (I don’t think uncertainty is on our side). Is this a well-founded wondering or am I massively underestimating the ability of the models?

  74. Rob Nicholls says:

    John Hartz, thanks for the link re “Re-think IPCC reports.” It seems insane to me that experts working on IPCC reports aren’t paid for their monumental efforts. We’re talking about something that’s really important to the future of our civilisation and to the only biosphere which we know of. I know there are concerns that paying the authors would create conflicts of interest; there are probably compelling reasons for these concerns that I’m not aware of; but on the face of it, it doesn’t seem right, and this approach doesn’t happen in other fields where high ethical standards are expected. Efforts to make the process less burdensome to participants are very important (Presumably reviewing all the required literature and data gets harder and harder with every round as there is more and more of it each time. Something has to give). It’s not right to put too much pressure on people and risk their well-being, even if they have volunteered. (Also, a system that puts too much strain on the experts on which it depends is not going to get the best out of those experts.)

  75. BBD says:

    And one might wonder at the dissonance with the usual way in which expert knowledge is remunerated.

    As dear old granny used to say, it’s enough to make a cat laugh.

  76. I’m willing to avoid playing Climateball for another round–as I agree that our focus should now turn to issues covered by WG2 and WG3.

    Back in the 90s the US EPA conducted a study of costs needed to protect the US coastal areas from sea level rise due to climate change and came up with a fairly modest figure–about 180 billion USD, although one would have to adjust for inflation to make it relevant today. It suggests that problems adapting to SLR will not be severe for OECD states (although neither will they be trivial).

    That would kick the ball back into the realm where I think our attention should be focused–helping the developing countries in SE Asia and the river deltas of Africa.

    As international aid for such purposes is already existent, if WG2 and 3 could just result in an increase in efforts proportionate to the additional stress on coastlines and deltas due to climate change, we would in my opinion be addressing the major problems we will see due to ACC.

  77. izen says:

    @-BBD
    RE the antiquity of plant domestication.

    http://www.sciencedaily.com/releases/2008/09/080919075005.htm

    There may be more recent work than this, its a while since I looked at the subject and DNA timelines are prone to updates…
    However the ‘instant’ mutation of grains to a domesticated form from the wild at Natufian sites was always a bit dubious genetically.

  78. Rachel M says:

    Guthrie,
    Yes, I was a bit surprised by Lucifer’s comment too. I live in a home that’s older than 100 years as do all the people on my street. I’m fairly sure this house will still be here in another 100 years as it’s made of stone and very solid. It’s also a nice place to live. I’ve always thought older houses, particularly those from the Victorian era, had soul and character and were good places to live.

    Rob Nicholls,
    The impacts are the most important thing to me also and I’ve written about it a few times.
    The impact of climate change on human health
    What’s in store for your habitat
    So this is it, we’re all going to die.

    Maybe the impacts are too wide and varied and uncertain for people to take notice. Or maybe people have too much going on in their lives to care about a future problem. It seems distant and unreal. But whatever the reason, it’s unwise of us to ignore them.

  79. verytallguy says:

    Tomfuller,

    There are two problems with your argument that coastal sea level rise is the only issue that needs to be dealt with.

    Firstly, it entirely ignores huge swathes of impacts eg

    Extensive biodiversity loss with associated loss of ecosystem goods and services results in high risks around 3°C additional warming (high confidence).

    Secondly it ignores the very large future commitments to sea level rise which will have already been made, not least 7m from Greenland.

  80. Verytallguy, once again, I can only assume you are reading too quickly, as did ATTP above.

    I wrote, “if WG2 and 3 could just result in an increase in efforts proportionate to the additional stress on coastlines and deltas due to climate change, we would in my opinion be addressing the major problems we will see due to ACC.”

    If you cannot see that ‘major’ is not semantically equivalent to ‘all’, then perhaps the fact the sentence is coming from me outweighs the actual meaning of the words I used.

    Do I think biodiversity is under threat? Yes. Do I consider global warming a potential threat? Yes.
    Do I think it is of the same magnitude as threats to coastal regions due to sea level rise? No.

    But that is primarily because the other threats to biodiversity are current and pressing. When we successfully address habitat loss, alien species, over hunting/fishing and conventional pollution then we can talk about future effects of climate change. If we sacrifice our efforts in those areas and focus primarily on climate change’s effects on biodiversity, I fear there will be no biome to protect by the time climate change is severe enough to pose a threat.

  81. Verytallguy, the IPCC does not offer any support what you write about sea level rise, especially that 7 meters from Greenland.

  82. Tom,
    It appears that there are a large number of experts who feel that the IPCC numbers were conservative – or, if not conservative, did not properly communicate the full range. See here.

  83. ATTP, there are also a large number of experts who do not feel the IPCC numbers were conservative. That would be the scientists whose work was reviewed by the IPCC and summarized in AR5. That would include the 12 lead authors, the 65 contributing authors and the four review editors.

    What they wrote was clear:”There is high confidence in projections of thermal expansion
    and Greenland surface mass balance… There has been substantial progress in ice-sheet modelling,particularly for Greenland. Process-based model calculations of contributions to past sea level change from ocean thermal expansion, glacier mass loss and Greenland ice-sheet surface mass balance are consistent with available observational estimates of these contributions
    over recent decades. Ice-sheet flowline modelling is able to reproduce the observed acceleration of the main outlet glaciers in the Greenland ice sheet, thus allowing estimates of the 21st century dynamical response (medium confidence).”

    Leading to this projection: “It is very likely that the rate of global mean sea level rise during
    the 21st century will exceed the rate observed during 1971–2010 for all Representative Concentration Pathway (RCP) scenarios due to increases in ocean warming and loss of mass from glaciers and ice sheets. Projections of sea level rise are larger than in the AR4, primarily because of improved modeling of land-ice contributions. For the period 2081–2100, compared to
    1986–2005, global mean sea level rise is likely (medium confidence) to be in the 5 to 95% range of projections from process based models, which give 0.26 to 0.55 m for RCP2.6, 0.32 to
    0.63 m for RCP4.5, 0.33 to 0.63 m for RCP6.0, and 0.45 to 0.82 m for RCP8.5. For RCP8.5, the rise by 2100 is 0.52 to 0.98 m with a rate during 2081–2100 of 8 to 16 mm yr–1.”

  84. Tom,

    there are also a large number of experts who do not feel the IPCC numbers were conservative. That would be the scientists whose work was reviewed by the IPCC and summarized in AR5. That would include the 12 lead authors, the 65 contributing authors and the four review editors.

    Yes, let’s play this game (by which I mean, let’s not).

    Why don’t you try reading what I posted properly? (especially as you’ve been moaning about others not reading your posts carefully enough) By using “likely” they were presenting the 66% range only, hence the possible upper limit was significantly higher than the apparent upper limit presented by the IPCC. So, maybe conservative is the wrong word, but the point is that the upper limit by 2100 could be considerably higher than the upper limit of the range presented by the IPCC.

  85. verytallguy says:

    Tom,

    I think you are mistaken on Greenland and the IPPC

    For sustained warming greater than some threshold, near-complete loss of the Greenland ice sheet would occur over a millennium or more, contributing up to 7m of global mean sea-level rise

    (this threshold is estimated at only 1-4 degrees above preindustrial)

    Perhaps reading less quickly would help?

  86. In fairness to Verytallguy, the iPCC does mention 7 meters due to complete Greenland melt. but…

    “The available evidence indicates that sustained global warming
    greater than a certain threshold above pre-industrial would lead
    to the near-complete loss of the Greenland ice sheet over a millennium
    or more, causing a global mean sea level rise of about
    7 m. Studies with fixed ice-sheet topography indicate the threshold
    is greater than 2°C but less than 4°C (medium confidence) of global
    mean surface temperature rise with respect to pre-industrial.”

    Medium confidence… over a millenium or more…

  87. So, ATTP, what do we do when respected scientists disagree?

  88. Tom,
    My point is that I don’t think they do. The IPCC simply presented the 1 \sigma range. If one considers the full range, then it could be considerably higher.

  89. Are you saying that as a physicist?

  90. Tom,
    Sorry, I’m not interested in your word games. Either engage constructively or go away. I have enough commenters without needing someone who’s past behaviour has been suffuiciently nasty that my interest in engaging with them is already pretty small.

  91. Hey, no problem. Have fun!

  92. @BBD March 6, 2015 11:16 pm

    Since Gornall et al (2010) there has been a lot more work trying to estimate global-scale impacts of climate change on agricultural productivity. Personally I’d still say that the statement you bolded, about global-scale impacts not being reliably quantified, still stands – there’s too many complicating factors that we don’t have a handle on yet. In particular, future changes in extreme weather, the impacts of this for productivity, and changes in pests and diseases are all things which it is hard to quantify. Also, productivity in many irrigated regions will depends not only on climate change in the local area but also changes many hundreds or even thousands of km away – and it’s not just changes in temperature and rainfall, but also other things like evaporation, glacier melt.

    HOWEVER, just because something can’t be reliably quantified, this doesn’t mean you can’t assess risks. Many components of projected future climate change will clearly be detrimental to agricultural productivity – very high temperatures are known to harmful, and so (obviously) is reduced water availability. Increased CO2 fertilisation will probably have beneficial effects but it’s not clear how much this will offset the negative effects of high temperatures and droughts. Since we don’t know how these things interact, there are risks of the negatives outweighing the positives.

    IPCC AR5 WG2 Chapter 7 is the best place to look for the latest on this. Some excerpts were posted above, but here’s some statements from the Exec Summary which I think are key conclusions regarding future global-scale risks:

    For the major crops (wheat, rice, and maize) in tropical and temperate regions, climate change without adaptation will negatively impact production for local temperature increases of 2°C or more above late-20th-century levels, although individual locations
    may benefit (medium confidence). Projected impacts vary across crops and regions and adaptation scenarios, with about 10% of projections for the period 2030–2049 showing yield gains of more than 10% and about 10% of projections showing yield losses of more than 25%, compared to the late 20th century. After 2050, the risk of more severe impacts increases. Regional Chapters … show crop production to be consistently and negatively affected by climate change in the future in low-latitude countries, while climate change may have positive or negative effects in northern latitudes (high confidence). Climate change will increase progressively the inter-annual variability of crop yields in many regions (medium confidence).

    Global temperature increases of ~4°C or more above late-20th-century levels, combined with increasing food demand, would pose large risks to food security globally and regionally (high confidence). Risks to food security are generally greater in low latitude
    areas.

    Changes in temperature and precipitation, without considering effects of CO2, will contribute to increased global food prices by 2050, with estimated increases ranging from 3 to 84% (medium confidence). Projections that include the effects of CO2 changes, but ignore O3 and pest and disease impacts, indicate that global price increases are about as likely as not, with a range of projected impacts from –30% to +45% by 2050.

    The difficulty in quantification is the main reason why the WG2 report is framed in terms of risk instead of predictions of impacts.

  93. @Brandon Gates March 6, 2015 11:07 pm

    Interesting but difficult question about tabulating best estimates of economic costs & benefits of impacts and mitigation by RCP.

    This is the kind of thing that economic models & integrated assessment models attempt to do, but personally I think the uncertainties in these things would be absolutely vast. The Stern Review attempted an exercise along those lines, although that pre-dated the RCPs (and it got a lot of flak).

    Given the issues I describe above with the uncertainties in impaction agricultural productivity, and the fact that similar issues apply to other sectors, I am dubious about whether such studies can be anything other than vaguely indicative. While individual authors may claim to have their own ‘best estimate’, these will vary wildly between studies (or at least they should if they are properly accounting for uncertainties in physical climate impacts!) so I doubt whether the community as a whole would hang its hat on any specific numbers.

  94. Kevin ONeill says:
    March 7, 2015 at 4:15 pm
    “TF is, of course, playing the game of trying to downplay any possible impacts……Likewise he equates Antarctic sea ice increases as somehow offsetting Arctic sea ice losses – even though the *impacts* of the two are vastly different.
    It’s a fool’s game and he’s been playing it a long time.”

    And the most important numbers don’t even begin to allow “Antarctic sea ice increases as somehow offsetting Arctic sea ice losses”. ATTP reported about a year ago on a study that estimated that the volume of Antarctic sea ice increases is an order of magnitude less than the volume of Arctic sea ice losses:

    “Antarctic sea ice volume”
    Posted on February 11, 2014 by …and Then There’s Physics
    https://andthentheresphysics.wordpress.com/2014/02/11/antarctic-sea-ice-volume/
    Quote:
    “The abstract says
    “The model suggests that overall Antarctic sea ice volume has increased by approximately 30km3/y (0.4%/y) as an equal result of areal expansion (20*103km2/y, or 0.2%/y) and thickening (1.5mm/y, or 0.2%/y). This ice volume increase is an order of magnitude smaller than the Arctic decrease, and about half the size of the increased freshwater supply from the Antarctic Ice Sheet.””

  95. John Hartz says:

    Here’s another thought-provoking article about the future of the IPCC, i.e., the topic of the OP:

    The unique intergovernmental panel has forged scientific consensus on climate change by steering clear of hot-button issues. Will new leadership find a way to address the most critical issues for curbing global warming?

    IPCC future hinges on greater relevance, amid tricky politics. by Marianne Lavelle, The Daily Climate, March 2, 2015

  96. BBD says:

    Izen

    Thanks for the link.

    However recent archaeological evidence has already begun to undermine this model pushing back the date of the first appearance of plant agriculture. The best example of this being the archaeological site Ohalo II in Syria where more than 90,000 plant fragments from 23,000 years ago show that wild cereals were being gathered over 10,000 years earlier than previously thought, and before the last glacial maximum (18,000-15,000 years ago).

    A few quick points: first, the finds at Ohalo don’t show agriculture prior to the LGM, simply gathering from wild sources (which is documented in eg. Mithen). Second, the proposed timescale is vague: ‘the Natufian’ goes from Early to Late and spans the YD. Third, the press release gets the dates for the LGM completely wrong!

  97. BBD says:

    Richard Betts

    Thanks very much for your response. I feel a bit guilty now for not simply going direct to WG2 ch7. Your patience is appreciated.

    😦

  98. BBD

    No worries – I think it was a useful addition to this thread.

  99. BBD says:

    Thank you, Richard.

    * * *

    Izen

    Sorry, what I wrote above is barely coherent. What I was trying to say is that there’s no evidence that agriculture began before the LGM (~21 -20ka). The argument that it may have emerged ~12.5ka / Early Natufian is persuasive, and seems to be supported by Allaby’s research.

  100. BBD says:

    Whoopsie.

    The argument that it may have emerged ~12.5ka

    Should be ‘~12.5ka BCE’.

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  102. Willard says:

    Richard Betts,

    I’ve cited your paragraph that starts with “HOWEVER” at Judy’s, in her latest “let’s wave our invisible hands” thread. A character from below replied:

    Nonsense.

    Droughts cause high temperatures ( heat is realized as sensible, not latent because of lack of water ).
    There’s no evidence the converse is true.
    Precipitation is largely a matter of fluid flow.

    ‘Very high temperatures’ are also a matter of fluid flow.
    Heat waves occur because of large stagnant summer time air masses which foster clear skies and increased solar load.
    When this occurs in winter, we tend to call it ‘nice weather’.

    http://judithcurry.com/2015/03/08/big-players-and-the-climate-science-boom/#comment-682126

    You might also be interested to know that Judy’s suggesting that you’re a victim of herding mentality an crony intellectual capitalism, if not a herder and a crony yourself.

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