Halting the vast release of methane is critical

A week or so ago there was a New York Times article called Halting the Vast Release of Methane Is Critical for Climate, U.N. Says. As the title suggests, it was reporting on a United Nations Report that (according to the article) is likely to suggest that slashing emissions of methane, the main component of natural gas, is far more vital than previously thought.

However, when discussing carbon dioxide emissions, the article claimed that:

while it remains critical to keep reducing carbon [dioxide] emissions, which make up the bulk of our greenhouse gas emissions, it would take until the end of the century to see the climate effects.

The problem was that this was wrong. As I point out in this post, if you consider pulses of carbon dioxide emissions, then the maximum warming from such a pulse would occur after about a decade. In other words, the warming from carbon dioxide emissions peaks relatively quickly. Consequently, any emissions we avoid will have an impact on a similar timescale. Hence, it’s wrong to claim that it will take till the end of the century to see the climate effects of reductions in carbon dioxide emissions.

What was impressive was that, after I pointed this out on Twitter, the author (Hiroko Tabuchi) responded to say that they were updating the article. They changed it from it would take until the end of the century, to it will take to the second half of the century. I still don’t entirely agree, but I thought it good that they were willing to take on board the criticism and didn’t really feel like quibbling.

I did want to add, though, that I think that what is being presented in the article is potentially what Ray Pierrehumbert was warning against in this Realclimate post. As I’ve pointed out in previous posts, short-lived greenhouse gases like methane behave differently to long-lived greenhouse gases, like carbon dioxide.

The warming impact of methane emissions largely depends on how these emissions have been changing with time. In fact, if we can get methane emissions to decrease, then that would actually reverse some of the methane-driven warming. When it comes to carbon dioxide, though, how much we warm depends essentially on how much we emit in total. So, limiting carbon dioxide-driven warming requires limiting how much we emit in total, and reversing carbon dioxide-driven warming would require artificially removing carbon dioxide from the atmosphere.

There are certainly good reasons for cutting methane emissions now, and it would almost certainly have an impact on a very short timescales. However, we do need to be careful of framing this as some trade-off between reductions in methane emissions and reductions in carbon dioxide emissions. To limit long term warming requires limiting how much carbon dioxide we emit. In the absence of some kind of negative emission technology, any delay in carbon dioxide emission reductions will either commit future greaters to greater warming, or will require much more drastic emission reductions in the future.

So, I do think we should be cautious of suggesting that because reductions in methane emissions can have a large short-term climate impact that we should focus on this now, partly because it’s not the case that this isn’t true for reductions in carbon dioxide emissions, and partly because long-term warming is going to be dominated by how much carbon dioxide we emit. Of course, if there are easy ways to reduce methane emissions now, then we should do so. There may also be other reasons for reducing methane emissions now and we certainly don’t want it to continue increasing. Let’s just not forget that to limit long-term warming requires limiting how much carbon dioxide we emit.

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94 Responses to Halting the vast release of methane is critical

  1. Tom Fuller says:

    Should we change how we feel about rice? Or at least call for change in paddy cultivation practices?

  2. Tom,
    If you’re referring to that rice cultivation emits methane, then I’m certainly not an expert on that particular process. However, this is one reason why it’s important to understand the relationship between methane emissions and warming. If methane emissions are not increasing then their warming impact is potentially small, and reductions in methane emissions can actually reverse some previous methane-driven warming. So, we don’t necessarily need to aim for net-zero methane emissions. If there are methane emissions associated with food production (which is clearly an important process), then we could look for ways to reduce those emissions, but we don’t need to aim for zero methane emissions (from a climate warming perspective, at least).

  3. Do you observe any evidence that humans can/will limit our carbon dioxide emissions in a significant way? Do you observe any evidence that humans can reduce methane emissions in a significant manner?

    I view all the back and forth about which ghg emission to address as akin to argument about the deckchairs on a certain luxury liner. Some folks believe the deck chairs should be in neat geometric rows and others like the chaos patterns that emerge when the chair sitters move things to their personal taste. Either approach is not going to matter much once we start taking on water.

    That said, I think, yes, let’s focus on CO2 with a carbon tax and manage methane emissions with an EPA fine if/when the source of emissions can be identified with enough certainty. No reason why we can’t do two things at once. I can walk and chew gum. No reason to choose one over the other if I want to walk and chew gum at the same time.

    Cheers

    Mike

  4. smallblue,

    Do you observe any evidence that humans can/will limit our carbon dioxide emissions in a significant way? Do you observe any evidence that humans can reduce methane emissions in a significant manner?

    Yes, I think we can and I think we’re already in a position where we’re unlikely to follow one of the higher emission pathways. We’re still not doing enough, and it’s still going to be challenging, but I do think it’s being taken much more seriously, I think we do have viable alternatives, and I think we are starting to see the impact of their implementation.

  5. Chris Smaje says:

    I’d argue strongly against changing paddy cultivation, especially when it’s for local consumption. Only 18% of agricultural methane emissions come from paddy, and it’s vastly more important nutritionally than ruminant meat, the latter being responsible for 74% of agricultural methane emissions. Also, N and P cycling in paddy systems work pretty much as a renewable closed loop, and the social structures of small scale paddy farming mesh well with food sovereingty and nutritional goals. As I think Ken is saying here, we shouldn’t over-emphasize the importance of methane in climate forcing, and inasmuch as we should emphasize it, I think paddy cultivation (especially existing rather than new paddy) comes very low on the list of concerns – much lower than methane emissions from the fossil fuel industry, for example.

  6. Chris,

    I’d argue strongly against changing paddy cultivation, especially when it’s for local consumption.

    Yes, I’m not an expert on this, but I am concerned about climate plans that might impact people who are simply cultivating food for local consumption.

    As I think Ken is saying here, we shouldn’t over-emphasize the importance of methane in climate forcing, and inasmuch as we should emphasize it,

    I don’t want to dismiss the importance of reducing methane emissions when it is possible to do so and when we can do so independently of reductions in CO2 emissions. However, it does have a relatively short atmospheric lifetime, and so any process that is not increasing its methane emissions is essentially not contributing to long-term climate warming.

    I think paddy cultivation (especially existing rather than new paddy) comes very low on the list of concerns – much lower than methane emissions from the fossil fuel industry, for example.

    Based on my understanding of the topic, I would agree. I think we can reasonably expect the fossil fuel industry to invest in processes that don’t emit methane into the atmosphere.

  7. “Yes, I think we can and I think we’re already in a position where we’re unlikely to follow one of the higher emission pathways.”

    I hear this and think it sounds good, but when I look at the pattern/trend of CO2 accumulation in ocean and atmosphere I do not see evidence that we have done anything significant.

    https://www.climate.gov/news-features/understanding-climate/climate-change-atmospheric-carbon-dioxide

    “Global atmospheric carbon dioxide was 409.8 ± 0.1 ppm in 2019, a new record high. That is an increase of 2.5 ± 0.1 ppm from 2018, the same as the increase between 2017 and 2018. In the 1960s, the global growth rate of atmospheric carbon dioxide was roughly 0.6 ± 0.1 ppm per year. Between 2009-18, however, the growth rate has been 2.3 ppm per year. The annual rate of increase in atmospheric carbon dioxide over the past 60 years is about 100 times faster than previous natural increases, such as those that occurred at the end of the last ice age 11,000-17,000 years ago.”

    It kind of comical to me that you are slightly unhappy with the reporting/spin/presentation by NYT of the emissions and I certainly agree with you that their original presentation about the “end of century” framing is very inaccurate. You and I would agree that the “second half of the century” framing is also inaccurate. In both cases, the impact of the NYT article may to be allow folks to read the paper of record and feel like our climate warming problems are decades away when that is almost certainly incorrect.

    I feel in a similar way that your framing of progress to avoid the highest impact scenarios is too rosy and again will allow folks to feel like we are doing enough when the evidence that I see does not suggest that we are engaging in changes that would bring us to a net zero status and net zero is where we need to be, right? Does it make sense to include a simple observation that “we need to get to net zero status asap to stop the warming and we are nowhere near that status as measured by the global atmospheric numbers.” I think that is where the rubber meets the road, so to speak.

    Good work pulling the NYT into presenting concerns about the impacts that we may start to experience in 30 years. I will have left the building by that time, so my observations at that point will likely cease.

    Cheers

    Mike

  8. smallblue,

    I hear this and think it sounds good, but when I look at the pattern/trend of CO2 accumulation in ocean and atmosphere I do not see evidence that we have done anything significant.

    To a certain extent you do need to compare against a counter-factual that we haven’t actually experienced. It is true, though, that we have yet to actually start reducing carbon dioxide emissions, but I think we’re on a better trajectory that we might have been on and I do think we may see peak emissions relatively soon. We should also, though, be careful of unfounded optimism.

  9. as to rice: why not push hard to move the rice growers to one of the cultivars that produce less methane?
    http://www.ciesin.columbia.edu/docs/004-032/004-032.html
    We can walk and chew gum, right? Rice or no rice are not the only options. Transition to low methane emission rice seems like a reasonable idea/option to remember and mention.

    Cheers

    Mike

  10. smallblue,
    I certainly don’t think there’s anything wrong with trying to find alternatives that might emit less methane. However, as Chris pointed out, I don’t think methane emission from rice cultivation should be high on our list of priorities when it comes to looking for sector that could do more to reduce their methane emissions.

  11. CS says “Only 18% of agricultural methane emissions come from paddy, and it’s vastly more important nutritionally than ruminant meat, the latter being responsible for 74% of agricultural methane emissions.”

    I think it’s hard to mention this one without being accused of wanting to take away hamburgers from hard working Americans, but in a way that is similar to the low emission rice cultivars, it may be worth mentioning that we have ways of reducing ruminant methane emissions: https://www.labiotech.eu/in-depth/feed-additives-cattle-methane-emissions/

    I am not sure if we will succeed at reaching net zero and stabilizing climate, but if we do, I am pretty sure that the path to that happy place is not simple, we will have to make many changes to many systems and address the problem(s) in a manner that is more complex than rhetorical. In that vein, I think we should talk about low emission rice cultivars and low emission ruminant feed formulas as important and urgent matters to facilitate.

    Cheers

    Mike

  12. David B Benson says:

    “United Report”
    “future greaters”
    ?

  13. David,
    Good catch, thanks.

  14. Twenty years ago if, globally, methane emissions had been stabilised (reducing emissions) then only cutting CO2 (and N2O, the long-lived gases) very quickly to net zero might have been enough to limit to 1.5ºC or “well below 2ºC”, but that is needed *and* also achieving substantial negative forcing by a combination of methane (and other SLCF) reduction and/or carbon dioxide removal (CDR) is needed. Now, “we” – the richest nations, corporations and persons first and foremost – need to achieve all of the above in combination using all GHG reduction levers.

    Within the Paris ºC limit context, methane reduction effectively acts as fast lever to limit overshoot of “fair share” national carbon quotas (however defined) of the remaining global carbon budget. For richer nations such quotas are rapidly heading toward overshoot so this is a strong international equity basis for urgent methane reduction. Otherwise there is also an intergenerational inequity in failing to achieve substantial methane reduction as it means a tacit (and costly) long-term CDR requirement for these nations to return to a fair share Paris quota level after overshoot.

    The ongoing rise in global methane emissions is alarming because any sustained change in methane flow has a big impact, increasing or decreasing methane-related warming.

    One of the points regarding methane that seems to be little appreciated, even by some climate scientists, is that the climate system temperature response behaviour of a sustained new flow (~ ongoing pulses) or a reducing flow is very different that of a single the pulse with its peak at 10 years from emission.

    By comparison, a sustained change in flow has a strong effect that has an impact of about 25x that of a single pulse and this impact takes about 30 years to taper off. That means that the result of any permanent methane reduction in 2021 will only have its full effect by 2050.

    This is why the IPCC SR15 illustrative pathways to meet 1.5ºC show most methane reduction (fossil and agri) taking place in this decade, by 2030, and levelling off the mitigation rate thereafter to reach about 50% of the 2010 level by 2050, when CO2 is passing through net zero. Adding more, later CDR, through BECCS, is the main modelling balance for not achieving methane reduction.

  15. Paul,

    One of the points regarding methane that seems to be little appreciated, even by some climate scientists, is that the climate system temperature response behaviour of a sustained new flow (~ ongoing pulses) or a reducing flow is very different that of a single the pulse with its peak at 10 years from emission.

    Maybe I misunderstand you, but if you’re suggesting that there is some confusion about the temperature response to methane emissions, then I agree. The warming due to methane depends strongly on the emission profile (i.e., rising, flat, falling) which is not the case for CO2.

  16. Not that. There is an increasing rhetoric, especially in livestock and gas vested interests, around memes including “methane is a short-lived gas”, as if it “disappears” after we delaying reductions is okay, and “biogenic” methane, as if agri methane is not important. Now that cutting methane is very important these interests have woken up to action-delaying tactics just as the coal and then oil industry did.

  17. Paul,
    Yes, I see what you mean, thanks. I find this quite a tricky issue, because it is clear that the warming impact of methane differs from that of CO2 and it’s worth, IMO, making this difference clear. However, there are some who are using this to then – as you say – to develop action delaying tactics.

    In a sense, it seems similar to the net-zero debate. Scientists present information and organisations with vested interests then utilise that information in ways that suits their agendas.

  18. Yes exactly that.
    [Apologies for my distracted typing above, but you interpreted correctly anyhow.]

  19. C Jarzbek says:

    Cutting methane emission has twice the effect one must take into consideration. After CH4 enters the atmosphere all of the O2 molecules have an affinity for it as in …. CH4 + 2O2 → CO2 + 2H2O.

    So for every molecule of methane you emit, you end up with a molecule of CO2

  20. C Jarzbek,

    So for every molecule of methane you emit, you end up with a molecule of CO2

    Yes, that is true. However, the amount of methane we emit is actually quite low when compared to the amount of CO2 we emit. So, the dominant warming effect is when it’s methane, not when it’s CO2. Also, if the source is biogenic, then this is not a new carbon (i.e., it was already part of the carbon cycle). Methane release associated with fossil fuel extracting is adding a new carbon and hence, ultimately, adding CO2 to the atmosphere.

  21. Chris Smaje says:

    Thanks for the informative discussion. If indeed it’s necessary to reduce methane emissions to hit CC targets presumably there should be some prioritisation. Different rice varieties might be worth trying, but I still think spending resources persuading smallholder farmers with minimal climate impact to change their ways should come low on the list and would give a poor return on investment. Maybe there’s a stronger case with beef farming, but it seems to me the main pushback here is again from the more marginal/holistic pasture-based sector which, though it sometimes inflates its claims, maybe has a point about the low impact of well managed grasslands. In any case, it’s a very minor vested interest compared to fossil fuel producers and consumers who seem to prefer to identify anything – rice, beef, tree-planting – other than fossil fuels as the way forward. Presumably Ken’s point about biogenic methane in the agricultural sector is also relevant here, lowering its climate impact relative to fossil fuels?

  22. I did write a post about agricultural emissions, which quoted a paper as saying:

    reducing methane emissions at the expense of CO2 is a short-sighted approach that trades a near-term climate benefit with warmer temperatures for every year thereafter

    and that

    If strong efforts are made to reduce agricultural emissions but prove expensive—in terms of monetary costs, political capital, public goodwill, or individual effort—and detract from efforts to eliminate fossil CO2 emissions then we will be climatically worse-off.

  23. “Ken’s point about biogenic methane in the agricultural sector is also relevant here”

    Is it? It seems to me that we have to remember that the carbon cycle (and other greenhouse gas cycles) may function differently on a warmed planet. I think at some point, every bit of ghg in the atmosphere is simply a problem for us and the source of each bit becomes an academic question if we continue to see the raw numbers rise.

    Here’s an example of how things can change in the “natural” cycles in ways that we need to keep in mind:
    https://www.theguardian.com/environment/2021/apr/30/brazilian-amazon-released-more-carbon-than-it-absorbed-over-past-10-years
    https://www.nature.com/articles/s41558-021-01026-5

    Ken and/or others may not be particularly concerned about these potential events that could happen at some future point, but that brings us back full circle to the criticism of the NYT for framing these matters as a future issue when they really are a present time issue with deep roots in our past actions and our lack of willingness to make changes that are required to stop the warming.

    I would also remind folks that over and over, the headline stories are about how the changes are happening faster/earlier than predicted/expected. Our species evolved in a climatological sweetspot of relative stability, but I think we are well on our way to pushing the planet to a different state and the next sweetspot of relative stability might not be to our liking.

    What’s wrong with being conservative about the impact we are having and following the precautionary principle?

    Need a recent example of “faster/earlier than expected”? Here you go: https://www.livescience.com/doomsday-glacier-close-to-tipping-point.html

    I agree with Ken that we should be concerned about unfounded optimism. It’s a good idea to be aware when unfounded optimism is apparent and maybe point that out.

    Maybe I am wrong about all or some of that. Maybe we will see the peak emissions happen soon and then start to decline as Ken believes will happen. I hope to live to see that. I think most of us agree that the peak emission moment has not happened yet.

    Here is one of the raw numbers that I track:

    March CO2

    Mar. 2021 = 417.64 ppm
    Mar. 2020 = 414.74 ppm

    That looks like 2.9 ppm increase yoy. That number gives me no comfort or joy.
    co2.earth

    If you are happy or content with that number and the trends that you discern, I am happy for you.

    Cheers

    Mike

  24. small,

    Ken and/or others may not be particularly concerned about these potential events that could happen at some future point,

    No, this is not the case. However, if we’re worried about some of these potential events, then a key thing is to limit long-term warming, and the key driver of long-term warming is CO2 emissions. This is not to suggest that we shouldn’t bother reducing methane emissions. We should also do this. However, we should be aware that the warming impact of methane and CO2 are different and that if we are worried about the impact of long-term warming, then the key GHG is CO2.

  25. I end up in the same spot with you that you arrived at with the NYT. You think and post about “a key thing which is to limit long-term warming.” I think that short and midterm warming factors are also significant and should be discussed. I appreciate that you engaged in the discussion and I don’t want to quibble with you, just as you stopped quibbling with the NYT at a certain point.
    Keep up the good work,
    Mike

  26. Chris Smaje says:

    So…my point about biogenic methand was more question than statement. But if it’s the case that we need to slash both methane & CO2 emissions very rapidly, bear in mind that the local agricultures that have developed in low energy situations have methanogenic elements like paddy or ruminants. If the poor small-scale farmers practicing them are expected to cut these elements out, this may create some difficulties for feeding ourselves in a low carbon world, and would certainly have to be accompanied by richer more urban people likewise avoiding emissions – no fossil fuelled cars, aeroplanes, boilers, blast furnaces etc. Otherwise we’ll probably have to figure in growing legitimation failures of goverments and political revolutions to the already heady climate change brew

  27. Chris,
    Given that long-term warming depends primarily on how much CO2 we emit in total, achieving our climate targets (1.5C, for example) would primarily require slashing CO2 emissions. Given the warming impact of methane, this would probably also require that we stop increasing methane emissions, but may not require that we also slash methane emissions. Of course, if we were able to easily do so, then there would be climate benefits, and we should certainly be expecting fossil fuel produces to commit to reductions in methane emissions. I don’t, though, think we should be expecting the same of small-scale farmers and there probably isn’t even a need to do so.

  28. Chris Smaje says:

    Thanks for that clarification Ken. That seems the sensible approach to me. I’m worried that if the pressure of climbing emissions fosters too indiscriminate an approach to methane reduction in the agricultural sector, it could have very counterproductive consequences.

  29. Chris says “If the poor small-scale farmers practicing them are expected to cut these elements out…”

    Incentives can be used to help small scale farmers reduce their biogenic emissions. I can’t think of a reason why a first world nation or a national government would not be able to subsidize low emission cultivars of rice or subsidize feed and/or feed supplements that reduce emissions from ruminants.

    I can’t think of any compelling reason that small scale and developing world farming could not take part in a wide-ranging approach to reducing emissions that produce global warming. It also seems like a good idea that first world nations should foot the bill on the incentives and technology that would help third world and small scale farmers reduce their personal emissions in a rather painless manner.

    Cheers

    Mike

  30. Watching a coral reef die as climate change devastates one of the most pristine tropical island areas on Earth
    https://theconversation.com/watching-a-coral-reef-die-as-climate-change-devastates-one-of-the-most-pristine-tropical-island-areas-on-earth-159792
    When I read a story like this one I think maybe it makes sense to address methane emissions to reduce global warming damage that is happening now.
    Cheers
    Mike

  31. Joe Clarkson says:

    It also seems like a good idea that first world nations should foot the bill on the incentives and technology that would help third world and small scale farmers reduce their personal emissions in a rather painless manner.

    I disagree. Small scale farmers in undeveloped nations have virtually nothing to do with excess carbon emissions. I fear that if first world people foot the bill for token carbon emissions reductions from those farmers they might believe that they were actually doing something significant to mitigate climate change and thereby distract themselves from getting their own houses in order.

    It is industrial civilization and the people to live in modernity that have emitted the vast majority of excess greenhouse gases and their high emission levels are ongoing. Only when first world nations have reduced their emissions to the level of undeveloped nations (presumably by abandoning modernity), should they even think about providing incentives for other low emitters.

    It is also likely that once first world nations reduce their emissions by 95%, or more, they will not be able to afford the incentives anyway. They will be too poor.

  32. Ben McMillan says:

    Although figures are variable, most emissions from beef/dairy are not methane (N2O& land use CO2 are big).

    The cooked-up outrage over Beef being cancelled highlights the issues going forward though…

  33. Ben,

    Although figures are variable, most emissions from beef/dairy are not methane (N2O& land use CO2 are big).

    Yes, I agree that we mustn’t forget that there are emissions of long-lived GHGs from beef/dairy.

  34. Joe,
    I don’t agree with the last part of your comment, but I do agree that maybe the developed world should primarily focus on reducing their own emissions, and leave the developing world how to decide for themselves how to progress.

  35. Ben says “The cooked-up outrage over Beef being cancelled highlights the issues going forward though…”

    Exactly. The culture wars pushback against addressing global warming is astounding in its stupidity. Plus, we have corporate entities still hard at work identifying new oil fields for development: https://www.cnn.com/2021/05/03/africa/namibia-oil-exploration-intl-cmd/index.html?utm_term=1620037641627fa2de20e3322&utm_source=cnn_Five+Things+for+Monday%2C+May+3%2C+2021&utm_medium=email&bt_ee=sBL%2F8Zxz%2BupmHXnXpd8UxRNSHUFEWXn3UjcqXCNYP5mNxhUYupy3IDss12DJRxBq&bt_ts=1620037641629

    I think these are the two big drivers that make progress on global warming reduction so slow. Maybe there are more, but it seems to me that culture war stupidity and profit-chasing are the big ones.

    Thanks for pointing out that methane is not the only emission with beef and dairy. The same is almost certainly true with a lot of non-meat agriculture. I have been clear that I think broadening our efforts to reducing greenhouse emissions as a class makes sense to me because whether the particular emission is long or short-lived in the atmosphere may be less important in some respects than the simple fact that the emission will produce additional warming on a planet that is already changing from the current level of warming.

    Cheers,
    Mike

  36. It seems to me that we should grab the low-hanging fruit in terms of ghg emission reduction by implementing relatively cheap and easy solutions like ruminant feed additives and low emission rice cultivars and use these solutions in the first world in a responsible manner, then first world nations should share these solutions and cover the costs or pay for incentives to help the developing world join us in addressing global warming.

    There is a lot of potential conflict in questions about whether first world nations should clean up their act first, but to me, that seems like a new version of a stupid, self-destructive culture wars and that might disappear if we decided to act as if we are all in this together. No emission reductions that we might manage in such a manner seems insignificant to me.

    I dream of such things.

    Cheers
    Mike

  37. Mitch says:

    About 20 to 25% of methane emissions are from fossil fuel:
    https://www.noaa.gov/media-release/study-finds-fossil-fuel-methane-emissions-greater-than-previously-estimated

    Unfortunately the study did not separate out the different microbial sources. Nevertheless, a big effect can be achieved by reducing the fossil fuel number.

  38. EPA moves to restrict powerful planet-heating gases in air conditioners and fridges

    “In the first move by Joe Biden’s administration to directly cut a greenhouse gas, the EPA has proposed a rule to drastically reduce the production and import of HFCs in the US by 85% over the next 15 years. The step is a significant one as Biden seeks to cut total US emissions in half by the end of the decade.”

    We can and should address global warming in several ways at the same time. This article says EPA is about to slam the door on some refrigerants that are potent global warmers. That does not mean that we can’t also move forward on reducing emissions for agriculture and beef/dairy industry. We can and should. None of that means we should not move forward on reducing CO2 emissions. CO2 is the big dog and the industries that profit from poorly constrained CO2 emissions will fight tooth and nail to wring the last dollar of profit out of fossil fuel reserves even if it kills lots of living things.
    Cheers,
    Mike

  39. Chris Smaje says:

    Mike writes: “There is a lot of potential conflict in questions about whether first world nations should clean up their act first, but to me, that seems like a new version of a stupid, self-destructive culture wars and that might disappear if we decided to act as if we are all in this together.”

    I don’t necessarily disagree with that, but the people who have almost all the power to make that decision are in the rich countries (and a couple of the richifying ones) – and quite simply they haven’t made that decision to date. Until they do, I doubt there will be much progress, and railing at the short-sightedness of poor country governments or poor farmers will achieve little. As Joe says above, if they do make the decision, I think they’ll find themselves less rich pretty quickly, and this does strike me as quite a problem – an open access tragedy, essentially.

    On a separate point, it’s important to distinguish between the impact of the present livestock industry and of livestock in low energy smallholder systems. In the case of the latter, I think the emissions mostly are methane?

  40. Vidar says:

    Wouldn’t accumulation of heat in the oceans make CO2 caused warming to be even more delayed than a decade? And therefor the effect of reduced CO2 emissions will take longer than a decade to respond?

    What I think of, is when the ocean becomes warmer, it emits more water vapor, which in turn does its magic to increase the heating furter. Even if water vapor is a condensable gas, and for that reason is a short lived gas, it is constantly being emitted from the water surface, making it a ‘long lived’ gas.

    Removing CO2 from the atmosphere is probably a dead end. Not because it doesn’t work, but for one it takes redicolus amounts of energy per CO2 unit, while the atmosphere consist og approx 3100 Gt of CO2, where at least 20% of that must be removed to reach 1990 levels. That assumes zero emmisions from day one (which is not going to happen any time soon).
    Secondly, removal of CO2 will most probably be an excuse to keep digging for more oil and coal.

    I’m not an expert. Just thoughts.

  41. Vidar,
    A key point is that there is a difference between what happens if we fixed atmospheric concentrations and stop emitting. If atmospheric CO2 concentrations are fixed, then we would keep warming for a long time because of the large heat capacity of the oceans. However, if we stop emitting CO2, atmospheric CO2 concentrations actually drop as the natural sinks continue to take up some of our emissions. A consequence of this is that this continue uptake balance the delayed warming so that warming soon stabilises. This is essentially the case if we consider individual pulses of emissions. The initial pulse increases atmospheric CO2 and causes warming. However, some of this pulse of emissions is taken up by the natural sinks so that the peak warming due to this pulse of emission happens relatively quickly (within about a decade, or so).

  42. Bob Loblaw says:

    “Even if water vapor is a condensable gas, and for that reason is a short lived gas, it is constantly being emitted from the water surface, making it a ‘long lived’ gas.”

    …and it is constantly being condensed and rained/precipitated out. And the rates balance, in manner where the mean atmospheric quantity is a function of temperature, not evaporation or precipitation rates. Pump more water vapour in, more will precipitate out. Hence, in the long term, it is a fixed quantity (global mean), unless something else comes along to change global atmospheric temperatures (e.g., CO2, solar forcing, etc.). At that point, it becomes a feedback, not a forcing.

  43. Russell says:

    Given the UN report’s admonition that:
    “slashing emissions of methane… is far more vital than previously thought.”

    More attention should be paid to methane from dammed rivers. Prodigeous amounts of organic matter are trapped and converted to methane by anaerobic fermentation in the warm depths of reservoirs created by tropical dam projects , including those on the Nile and Mekong.

    Methane emission from Lake Nasser, behind the Aswan Dam, reportedly accounts for half of Egypt’s carbon footprint, and the latest Nile dam may do the same for Ethiopia. Needless to say, some of the water in both reservoirs will find its way to rice paddies.

    On the bright side, methane from surface reservoirs plays a far greater role in radiative forcing elsewhere in the solar system:

    https://vvattsupwiththat.blogspot.com/2021/05/nasa-releases-chilling-kraken-data.html

  44. Chubbs says:

    The current methane spike continued last month with a 20 ppb year-on-year increase. Believe that is the largest year-on-year increase in the NOAA’s series.

    https://www.esrl.noaa.gov/gmd/ccgg/trends_ch4/

  45. Ben McMillan says:

    The rapid increase in CH4 levels shown in the NOAA graphs is indeed a worry; at worst you probably want to hold CH4 levels constant, so some level of effort seems worthwhile.

    Some of these CH4 emissions reductions are low-hanging fruits indeed, because e.g. fixing leaking fossil gas equipment is essential for several other reasons. Some of them will probably happen more slowly; e.g. watching movies recently, there is a lot of oat drink appearing on breakfast tables.

  46. Reducing methane is good for climate, health and can pay for itself – yet emissions are still rising fast, a new UN report warns

    “The top takeaway is that methane is going up very quickly, and it needs to drop by nearly half by 2030 to keep global warming under 1.5 degrees Celsius (2.7 F) if we hope to stay on the lowest-cost path. That means we have a rapid U-turn to make.

    The good news is that we have a lot to gain by cutting these emissions.

    Methane is a potent greenhouse gas, but it’s also a precursor of surface ozone, which is a toxic air pollutant. So, reducing methane improves the quality of the air we breathe at the same time that it reduces climate change, and the results are almost immediate.”

    https://theconversation.com/reducing-methane-is-good-for-climate-health-and-can-pay-for-itself-yet-emissions-are-still-rising-fast-a-new-un-report-warns-160423

    I don’t think there is much question that we should be working hard to reduce methane emissions. And sooner is better than later for a number of reasons. Eyes on the prize: dropping emissions of all greenhouse gas emission so that global warming and ocean acidification will stop.

    Cheers

    MIke

  47. Raypierre says:

    The only real prize is achievement of net zero co2 emissions. Without that, the Earth will just continue to warm indefinitely. Until we make progress on co2 methane is just a sideshow. Investment in co2 emission reduction gets you toward the main goal. Investment in methane does not. The confusion on methane comes from a focus on short term temperature targets , ignoring what happens afterwards. All made abundantly clear in my Annual Reviews article from some years back. Of course, it still makes sense to do low or negative cost methane abatement, but we shouldn’t delude ourselves about how much of the problem it can address.

    I could only wish that the media covering this were as perceptive as attp. Both the economist and the Guardian used the absurd and misleading gwp20 metric to compare methane to co2 effects.

  48. Ray,
    Thanks for the comment. I (virtually) attended a net-zero meeting yesterday evening. Was very interesting, but it seems clear that those on the policy side favour GWP over GWP*. However, some in the comments did make the point you’ve made above reductions in CO2 emissions being key.

    One argument that was made against using GWP* was that it becomes possible to hit net-zero while still emitting CO2. If governments/industries then use that to claim that they’ve now met the target and then do no more, you could then end up with continued CO2 emissions. I can see the point, but it doesn’t seem all that difficult to stress that net-zero, or better, has to be sustained and that achieving net-zero doesn’t them mean it’s all over and we can relax.

    I may be wrong, but it does seem as though the point you’ve made in your Realclimate post (that reducing methane emissions at the expense of reductions in CO2 emissions) isn’t entirely appreciated.

  49. Raypierre says:

    Ken, you are right that the point I made in the rc post isn’t broadly appreciated but it’s not for want of trying. I hate repeating myself once I’ve published something right, but I repeated the point in an article with.Susan Solomon, and in my Annual Review article, and the point is also made through all the Oxford group work on GWP*. To no avail. Even GWP* is imperfect in comparison to treating methane and hfc separately from co2, But for those who insist on aggregating, it is way better than gwp100, and way way better than gwp20

  50. A new report from the UN Environment Programme (UNEP) estimates that rapid action on methane emissions could take 0.3C off global temperatures by 2045, the Independent says. The report warns that “atmospheric concentrations of methane are at their highest level since records began about 40 years ago”, the outlet explains, but “through a combination of measures targeted at agriculture, fossil fuel production and the waste industry, methane emissions could be slashed by 45% by the end of the decade”. The reports says this would “be necessary to help meet the Paris Agreement’s goal of limiting global temperature rise to 1.5C by the end of the century”, the outlet adds. UNEP notes that such “rapid and significant reductions” in emissions “are possible using existing technologies and a very low cost”, says BBC News.
    https://www.carbonbrief.org/daily-brief/urgent-action-on-methane-emissions-could-shave-0-3c-off-global-temperatures-by-2045-un-report-says?utm_campaign=Carbon%20Brief%20Weekly%20Briefing&utm_content=20210507&utm_medium=email&utm_source=Revue%20Weekly

    hmm… existing technologies that can be deployed at low cost and would reduce global temps by 0.3C by 2045? I think that sounds very good.

    I agree with Raypierre and anyone who says achievement of net zero CO2 emissions is a real prize. It is not the only real prize within our grasp in my opinion.

    I don’t think anyone who is advocating for reductions in methane emissions is arguing against working for reductions in other greenhouse gas emissions or denigrating the possibilities that arise with reduction of other ghg emissions. I think the “real prize” is a planet where global warming and ocean acidification are stopped. But that’s just me.

    Cheers

    Mike

  51. Ben McMillan says:

    I think a lot of the disagreement about GWP^ stems from a difference in opinion on what kind of timescales and outcomes are plausible, or desirable, rather than people just ‘not understanding the physics’.

    e.g., if you think peaking under 1.5C and getting to net-zero in the next 15 years is necessary, it is perfectly consistent to think methane is a big deal right now (I think smallbluemike is arguing along these lines).

    I’d be much more sympathetic to the idea that methane reductions are overrated if we were currently doing too much. While that policy dial is stuck on zero, I’m inclined to support people wanting to turn it up.

    There isn’t a physics reason why methane emissions reductions need to be at the expense of CO2 emissions reductions, and the politics and economics are pretty murky. e.g. fossil coal and gas emit both, so taxing both would tend to have a synergistic effect.

    I’m inclined to think that the current carbon markets (e.g like in the EU) are far too narrow and would benefit from being broader. You would want to avoid a situation where people massively increased unregulated methane emissions in order to make a bit of money on the CO2 market.

    Imagine if people were building out long-lived fossil gas infrastructure and claiming it was cleaner than coal on the basis that CH4 is a short-lived pollutant.

  52. Raypierre says:

    @smallbluemike: As I said in one of my tweets on this. 0.3C by 2045 is a useful contribution in the context of a 1.5C or even 2C equilibrium temperature target, but what most of the discussion ignores is that unless we get CO2 emissions to net zero quite rapidly, we are going to blow way past 1.5C or 2C, and then your 0.3C is going to look like small potatoes. So, until we are sure we are going to hit net zero in a timely fashion, methane (and hfc) is just a sideshow. Consider also that pushing too hard on agricultural methane is politically fraught, and can distract from bigger things that should be done. It’s a matter of political capital, not just economic cost. Also, though of course we should eat less beef, other ruminants, and dairy, consider the guy who puts all his psychic effort into a monumental struggle to give up beef and cheese, then feels he did his bit and so neglects insulating his house, getting an electric car, or replacing his gas boiler with a heat pump.

  53. paulski0 says:

    Chubbs,

    The most likely culprit for the methane spike is a reduction of the OH (Hydroxyl Radical) methane sink due to pandemic-induced decline of NOx emissions. Intuitively, emissions should have declined or at least increased by less than normal in 2020 relative to 2019, though methane emissions can be somewhat complex.

    A corollary given NOx being the culprit is that tropospheric Ozone should have declined, and it’s generally understood that the two effects mostly cancel out in terms of radiative forcing. So, climate-wise it may not be a big deal.

    In the short term of the next year or two methane growth should return to more like a 10ppb/yr level as NOx levels recover. But beyond that, if EVs take over then we can expect a strong long-term NOx decline which would cause a relative acceleration in methane.

  54. Raypierre says:

    @ben But so far as climate goes , methane is cleaner than coal. That’s crystal clear, and just a matter of physics. Switching from coal to methane will reduce warming, and in that sense is useful. However switching from coal to methane is not as good as switching from coal to renewables or nuclear.

  55. Ben McMillan says:

    Raypierre: Obviously, I could have been clearer, my point was not ‘coal is better than gas’ but just that the consequences of building out gas infrastructure are long-term even if CH4 doesn’t hang around in the atmosphere that long.

  56. Russell says:

    Raypierre is of course right to prefer hydrogen rich fuels over more carbonaceous ones,
    but we should also endeavour to manage the carbon footprint of the second most important species of large animals on the planet as best we can,

    Perhaps we should ruminate more deeply on producing carbon neutral or negative beef:

    https://vvattsupwiththat.blogspot.com/2021/05/carbon-sequestration-heres-beef.html

  57. Ben McMillan says:

    I guess this is the CCAC/UN report that the NYT article was about which is indeed very positive about reducing methane emissions:

    https://www.ccacoalition.org/en/resources/global-methane-assessment-full-report

  58. Raypierre says:

    @Russell: That post on beef is a joke, right? A less obviously wrong claim about beef is that well-managed pasture can take up enough carbon to offset the emissions of beef. Note that what is commonly sold in North America as “grass fed beef” actually involves a lot of external inputs, and winds up being worse on all three GHG emissions (CO2, CH4, N2O) than feedlot beef. (see the “Midwest Pastured System” results in my ERL paper with Gidon Eshel). But even for well-managed pasture, people in the Oxford Livestock, Environment and People project whom I respect have concluded that the carbon storage potential for pasture has been oversold, in part because a lot of studies involve rather short term uptake and don’t take into account the saturation of the soil carbon stock. There is a good overview in “Grazed and Confused” https://www.oxfordmartin.ox.ac.uk/publications/grazed-and-confused/

    @Ben McMillan: Yes,that’s the report. In my view, the Climate and Clean Air Coalition has essentially turned into a lobbying group largely made up of people who have staked their careers on the premise that abatement of methane and other short-lived gases is urgent, and can be done without interfering with progress on CO2 abatement. Some of them have gotten quite famous by pushing this line. Draw your own conclusions. Their chief arguments are generally based on focusing on short-term temperature targets, ignoring what comes afterwards. They keep trotting out the same arguments with only minor variations, despite evidence to the contrary. The noise that CCAC makes interferes with the formulation of sound methane policy, which should concentrate on low-cost or negative cost measures (notably leakage from fossil fuel production). Most of the results of those measures you get automatically just by weaning the economy from fossil fuels — and that of course has to include natural gas, too, eventually. Even if it takes a while to get to net zero CO2 emissions, the fugitive methane emissions you incur in the meantime at worst just lead to a temporary temperature overshoot, which goes away in a decade or two.

    Agricultural methane doesn’t go away automatically in that scenario, of course, but dealing with agricultural methane isn’t a low-cost measure, either economically or politically. The main answer to ag methane is for people to give up beef, other ruminants, and dairy, but that’s not an easy sell, especially for dairy.

    The livestock industry also has a major climate impact through deforestation for soybean production, but that’s mainly a CO2 issue, not a methane issue.

  59. BBD says:

    Raypierre sez:

    [q]but what most of the discussion ignores is that unless we get CO2 emissions to net zero quite rapidly, we are going to blow way past 1.5C or 2C, and then your 0.3C is going to look like small potatoes.[/q]

    +1

    The methane thing is just this decade’s reprisal of the contrarian focus on black carbon.

    It’s a continuing narrative of misdirection.

  60. Russell says:

    Raypierre has read the masthead of The Climate Wars correctly- the post is facetious, the semiotics of the Sequestered CO2 Glut not so much.

    With kilotonnes of generic captured carbon on offer, almost anything consumers want can now be made out of thin air at fairly low marginal cost, from carbon fiber airplanes to plastic bags, and pharmaceuticals.

  61. Ray,

    Most of the results of those measures you get automatically just by weaning the economy from fossil fuels — and that of course has to include natural gas, too, eventually. Even if it takes a while to get to net zero CO2 emissions, the fugitive methane emissions you incur in the meantime at worst just lead to a temporary temperature overshoot, which goes away in a decade or two.

    Yes, it would seem that a reasonable amount of methane emission reductions could come about simply by reducing fossil fuel use. Also, even in the agricultural sector, you’d think that some reductions would come about through reducing CO2 emissions (land-use change, for example).

  62. angech says:

    “A week or so ago there was a New York Times article called Halting the Vast Release of Methane Is Critical for Climate, U.N. Says. , it was reporting on a United Nations Report that is likely to suggest that slashing emissions of methane, the main component of natural gas, is far more vital than previously thought.”
    A few thoughts.
    Is the vast release referring to our increasing use of natural gas or is this just a by product of the cows and tundra concern.


    Taken at face value one would tend to think that if natural gas is the concern, and it s being burnt and converted into CO2 anyway , that there would not be enough left over tho be a concern

    If it is cows and tundra then one would have to think we have been through these cycles many times before.
    So ho hum.
    .

  63. angech,

    Is the vast release referring to our increasing use of natural gas or is this just a by product of the cows and tundra concern.

    No, it’s referring to the actual emission of methane into the atmosphere. This is a partly a by-product of fossil fuel extraction, and partly due to agricultural emissions (cows, rice, etc).

    Taken at face value one would tend to think that if natural gas is the concern, and it s being burnt and converted into CO2 anyway , that there would not be enough left over tho be a concern

    It’s not referring to natural gas that is used as a fuel. However, it is true that it will decay into water and CO2. However, if it has a fossil origin, then it is a new carbon and hence increases atmospheric CO2. However, it is a relatively small addition when compared to the direct emission of CO2.

    If it is cows and tundra then one would have to think we have been through these cycles many times before.

    Technically the methane emitted due to agriculture is already part of the fast carbon cycle. Consequently, the issue is more to do with how this is changing, than it existing. In other words, if agricultural methane emissions are increasing, then this will produce warming. If we could get agricultural emissions to stabilise, then warming should also stabilise. If we could get agricultural emissions to go down, then we could reverse some past methane-driven warming.

  64. Ben McMillan says:

    Sorry, I feel like making the opposite case, just to flesh this out a little, even though I don’t think ignoring methane completely for the moment would be so terrible.

    I’m pretty sure that the economists would tell you to just put a price on CO2 and CH4 and let people sort it out, rather than hope the CH4 reductions happen as a lucky side-effect (because otherwise people might make the wrong tradeoffs).

    If I understand correctly, the policymakers would be happy enough to set the price ratio using GWP100. That wouldn’t be that far off the ratio you’d get by trying to calculate the current social cost of CO2 + CH4 separately in a 1.5C or Paris-compliant scenario in an IAM (even if you set the discount rate very low).

    If you just want to avoid doing anything about agriculture, then it would be more logical to just exclude agriculture anyway (which is what e.g. the EU ETS does) because a lot of these emissions are N2O and CO2. Splitting off methane seems the wrong mechanism.

    I sort of wonder too if e.g. Indian and Chinese scientists might take a somewhat different view of these issues.

  65. Ben,
    I’m certainly not suggesting we should ignore methane. At it’s simplest level I would argue that we should be aware of the difference between long-lived and short-lived greenhouse gases and should probably be aware of the difference between methane release associated with fossil fuel extraction and agricultural emissions.

    As I understand it, one of the reasons why some are reluctant to consider switching from something like GWP100 to GWP* is because policy-makers have largely accepted GWP100 and a switch might simply complicate things. There also seems to be this concern that with GWP* we could reach net-zero-equivalent while CO2 emissions are still non-zero, which means atmospheric CO2 cconcentrations could continue climbing if we don’t then sustain net-zero (which would require net-zero CO2). There’s also an argument about grandfathering (which I don’t quite understand) but I think is related to countries that have had historically high methane emissions using GWP* to argue against reducing their methane emissions.

    I guess that my general view is that, whatever we do, we need to focus on getting CO2 emissions to (net) zero even if we do also introduce policies for reducing methane emissions.

  66. Raypierre says:

    @Ben: Putting a price on CH4 that stimulates the right kind of decisions relative to CO2 is not easy. The reasons are laid out in my Annual Reviews article, and elaborated and made more useful in the GWP* stuff that the Oxford group has been pushing (with occasional help from me). The problem is that GWPn, for any n, tries to make a kilogram for kilogram equivalence between CH4 (or HFC) and CO2. In reality for the short lived stuff, the climate effects are sensitive to the emission RATE averaged over the past decade or so — kg/year — whereas for CO2 the climate effects are sensitive to the cumulative emissions (kg). GWPn (whether n = 20 or 100 or whatever) doesn’t even have the right units to capture the relative climate effect. GWP* does better, though it’s still not perfect, but developing a trading scheme based on GWP* is not at all straightforward. For that reason, I think methane and HFC policy should be handled by direct regulation of emissions, rather than a market mechanism. There may be some possibility to set up a two-basket trading scheme, where after targets are set, you could trade CH4 or HFC emissions against each other, but not trade them against CO2. CH4 is a flow pollutant, whereas CO2 is a stock pollutant. There is simply no good way to trade them against each other.

  67. The Vermont Cynic (UVM) sez …
    https://vtcynic.com/

    Easier said than done, circa 2021 literature review.

    Agriculture’s Contribution to Climate Change and Role in Mitigation Is Distinct From Predominantly Fossil CO2-Emitting Sectors
    https://www.frontiersin.org/articles/10.3389/fsufs.2020.518039/full
    “Agriculture is a significant contributor to anthropogenic global warming, and reducing agricultural emissions—largely methane and nitrous oxide—could play a significant role in climate change mitigation. However, there are important differences between carbon dioxide (CO2), which is a stock pollutant, and methane (CH4), which is predominantly a flow pollutant. These dynamics mean that conventional reporting of aggregated CO2-equivalent emission rates is highly ambiguous and does not straightforwardly reflect historical or anticipated contributions to global temperature change. As a result, the roles and responsibilities of different sectors emitting different gases are similarly obscured by the common means of communicating emission reduction scenarios using CO2-equivalence. We argue for a shift in how we report agricultural greenhouse gas emissions and think about their mitigation to better reflect the distinct roles of different greenhouse gases. Policy-makers, stakeholders, and society at large should also be reminded that the role of agriculture in climate mitigation is a much broader topic than climate science alone can inform, including considerations of economic and technical feasibility, preferences for food supply and land-use, and notions of fairness and justice. A more nuanced perspective on the impacts of different emissions could aid these conversations.”

    Offsetting unabated agricultural emissions with CO2 removal to achieve ambitious climate targets
    https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0247887
    “The Representative Concentration Pathway 2.6 (RCP2.6), which is broadly compatible with the Paris Agreement’s temperature goal by 1.5–2°C, contains substantial reductions in agricultural non-CO2 emissions besides the deployment of Carbon Dioxide Removal (CDR). Failing to mitigate agricultural methane and nitrous oxide emissions could contribute to an overshoot of the RCP2.6 warming by about 0.4°C. We explore using additional CDR to offset alternative agricultural non-CO2 emission pathways in which emissions either remain constant or rise. We assess the effects on the climate of calculating CDR rates to offset agricultural emission under two different approaches: relying on the 100-year global warming potential conversion metric (GWP100) and maintaining effective radiative forcing levels at exactly those of RCP2.6. Using a reduced-complexity climate model, we find that the conversion metric leads to a systematic underestimation of needed CDR, reaching only around 50% of the temperature mitigation needed to remain on the RCP2.6 track. This is mostly because the metric underestimates, in the near term, forcing from short-lived climate pollutants such as methane. We test whether alternative conversion metrics, the GWP20 and GWP*, are more suitable for offsetting purposes, and found that they both lead to an overestimation of the CDR requirements. Under alternative agricultural emissions pathways, holding to RCP2.6 total radiative forcing requires up to twice the amount of CDR that is already included in the RCP2.6. We examine the costs of this additional CDR, and the effects of internalizing these in several agricultural commodities. Assuming an average CDR cost by $150/tCO2, we find increases in prices of up to 41% for beef, 14% for rice, and 40% for milk in the United States relative to current retail prices. These figures are significantly higher (for beef and rice) under a global scenario, potentially threatening food security and welfare. Although the policy delivers a mechanism to finance the early deployment of CDR, using CDR to offset remaining high emissions may well hit other non-financial constraints and can thus only support, and not substitute, emission reductions.”

    Technical note: On comparing greenhouse gas emission metrics
    https://acp.copernicus.org/articles/21/4699/2021/
    “Many metrics for comparing greenhouse gas emissions can be expressed as an instantaneous global warming potential multiplied by the ratio of airborne fractions calculated in various ways. The forcing equivalent index (FEI) provides a specification for equal radiative forcing at all times at the expense of generally precluding point-by-point equivalence over time. The FEI can be expressed in terms of asymptotic airborne fractions for exponentially growing emissions. This provides a reference against which other metrics can be compared.

    Four other equivalence metrics are evaluated in terms of how closely they match the timescale dependence of FEI, with methane referenced to carbon dioxide used as an example. The 100-year global warming potential overestimates the long-term role of methane, while metrics based on rates of change overestimate the short-term contribution. A recently proposed metric based on differences between methane emissions 20 years apart provides a good compromise. Analysis of the timescale dependence of metrics expressed as Laplace transforms leads to an alternative metric that gives closer agreement with FEI at the expense of considering methane over longer time periods.

    The short-term behaviour, which is important when metrics are used for emissions trading, is illustrated with simple examples for the four metrics.”

    Net-zero emissions targets are vague: three ways to fix
    https://www.nature.com/articles/d41586-021-00662-3
    “To limit warming, action plans from countries and companies must be fair, rigorous and transparent.”
    “Next steps
    Countries and companies must add rigour and clarity to their net-zero targets, to enable these to be evaluated and assessed (see ‘Checklist’ and Supplementary information).”

    GWP100 (or GWP-100 using Reference 3 therein which is circa 2018)

    Meanwhile, back at the ranch …

    Is this all a bait-and-switch, a Ponzi scheme, three-card Monte, robbing Peter to pay Paul, carbon trading scam, Nero fiddled while Rome burned (has become a phrase used to criticize someone who is doing something trivial or irresponsible in the face of an emergency, but pedants) or simply procrastination? I am going with procrastination.

  68. EFS,
    I think your middle figure does show something important, which is that a net-zero GHG target would be expected to lead to a reduction in overall warming, while a net-zero CO2 target would lead to warming stabilising. However, what isn’t made clear is that getting to net-zero GHGs requires some level of negative emissions, given that it’s extremely difficult to get to zero non-CO2 emissions. I’m not sure this is fully appreciated.

    Ultimately, I think the point that Ray made in his last comment is key:

    CH4 is a flow pollutant, whereas CO2 is a stock pollutant. There is simply no good way to trade them against each other.

    Maybe it’s better to simply treat them independently, although I can see why some are reluctant to change a metric that seems to have been accepted by policy-makers.

  69. Left out shell game … rats …
    https://en.wikipedia.org/wiki/Shell_game
    https://en.wikipedia.org/wiki/Confidence_trick
    “Short and long cons
    A short con or “small con” is a fast swindle which takes just minutes (sic months). It typically aims to rob the victim of everything in his wallet.

    A “long con” or “big con” (also, chiefly British English: long game) is a scam that unfolds over several days or weeks (sic several years or decades); it may involve a team of swindlers, and even props, sets, extras, costumes, and scripted lines. It aims to rob the victim of huge sums of money or valuables, often by getting him or her to empty out banking accounts and borrow from family members.”

    I really do not think it is a confidence trick (e. g. short or long con, well except for those so-called fossil fuel interests). Just. you know, something in the human condition that is unable to properly evaluate long term sustainabilities and take appropriate actions in a somewhat timely manner.

  70. Willard says:

    To be a con, the scheme needs to turn some misguided personal interest against the mark. In the case of Sky Dragons, it’s all about being privy to the new Galileo. Coincidentally, there’s one such scheme called The Galileo Movement.

    Red pills sell.

  71. Russell says:

    Raypierre, i just ran some numbers from the hydrophonic cattle feed links in Cattle Today, and was surprised by the results– in praxis, you can grow 100 KG of barley sprouts a day in an area of five square meters:
    “The FodderKing 12-24 is CropKing’s largest hydroponic fodder system, with the capability to produce upwards of 210 pounds of fresh green sprouts on a daily basis… With a footprint of only 13’ x 4’ x 6’1” “.
    At a claimed gross cost of six to ten cents a kilo:

    “FodderTech sprouting systems are extremely efficient and cost effective. The costs of grain, energy, labor, water, and nutrient range from $0.03 – $0.05 per lb across different parts of the globe. “

    As it takes roughly 20 kg of sprouted feed to add 1 kg of edible beef a day to a growing steer,
    the inference is that these closet-sized cornucopias : https://www.youtube.com/watch?v=6C-P-C6sFnc&t=94s
    can support the production of a tonne of beef a year at an added cost of only a few euro /kg.

    The catch is that you need captured carbon barley to start with, and the CO2 needed to render this modest proposal carbon negative costs hundreds a tonne to capture from the air, and hundreds more to convert into the greenhouse- raised barley the system sprouts..
    The surprise is that while captured carbon cattle may cost an order of magnitude more than the corn fed sort, that’s still an order of magnitude less than Japanese Wagyu beef- a 6.5 kg sirloin strip roast presently sells for $2,500 !
    https://www.markys.com/Deli-Meats-Pate-Poultry/Origin-Japan/

    So Beyond Beyond Burger may not be a joke after all.

  72. Chris Smaje says:

    I’ve been following this discussion with interest, though as a simple farmer and not a climate scientist some of it is a bit above my head. What I would say, though, is that it’s good not to think in terms of a straightforward trade-off between livestock GHGs and meat (or milk), especially in rapid decarbonization scenarios and in low-income scenarios. Livestock provide low CO2 nutrient vectoring in the absence of high energy fertilizer imports, as well as transport, traction, waste management, numerous useful byproducts (hide, horn, gut etc.), marginal grazing efficiencies, and storage/lardering facilities across the year. All of these will be more important in the kind of lower energy and lower capital scenarios that seem likely in the future, and the total herd size will likely decrease because of the additional pressures on croplands for human food and fibre. If policymakers focus simply on minimizing the proximal carbon intensity of foods or of livestock without asking how the farmed landscape would actually function ecologically in a lower energy/lower carbon future, they risk creating some perverse outcomes.

  73. Chris,
    What you highlight is probably why it’s worth being clear about the differences between long-lived and short-lived greenhouse gases and also the differences between the various sources of these greenhouse gases. How we might want to deal with CO2 emissions may well be different to how we might want to deal with methane emissions. Similarly, what we might want to do with respect to methane emissions associated with fossil fuel extraction may differ from what we might do about agricultural emissions and, similarly, we may not want to treat all agricultural emissions the same. I can see why some prefer a simple metric, but it may well be hiding a level complexity that we really should be considering.

  74. Long term global warming versus shorter term global warming impacts?

    “In conditions often likened to a pressure cooker, temperatures can surpass 40C (104F) in the summer. “Our models show annual mean temperatures across the Mediterranean increasing by up to 2C over the next 30 years,” says Christos Zerefos, a professor of atmospheric physics. “In the summer the air temperature will rise by more than 3C. Ecosystems will suffer.”

    Bakoyannis, the scion of a political dynasty, was elected to the post in 2019. He knows time is of the essence.”
    https://www.theguardian.com/world/2021/may/10/heat-athens-climate-crisis-mayor?utm_term=d728cb9c3a4311de1827729c1d71e327&utm_campaign=GuardianTodayUS&utm_source=esp&utm_medium=Email&CMP=GTUS_email

    I believe the warming reductions that we can accomplish easily and cheaply on methane could be the difference between life and death for a lot of living things on the planet. Hitting methane hard at the same time that we continue to work equally hard on CO2 reductions does not seem like a particularly difficult matter to assess and support. In terms of the trajectory of global temps over the next 30 years, reducing methane emissions is clearly low hanging fruit. We don’t have to throttle or impair small subsistence farming to have a significant reduction in methane emissions. We don’t have to stop work on CO2 emission reductions to work on methane emission reductions. I think the smart move is to focus on reduction of ghg emissions of all types.

  75. Ben McMillan says:

    I think I’d still leaning toward just using GWP100 and putting CH4 in existing frameworks. Not that it will make much difference either way.

    Agricultural emissions in general, on the other hand, are a big slice of the pie, so I think that those need to be dealt with pretty promptly, despite the political convenience of kicking the can down the road.

  76. Willard says:

    > I don’t think anyone is going to be burning coal or driving ICE cars in 2100 in a constant policy scenario.

    Perhaps, but if Africa, Asia, South-America, and Antarctica (why not) start to drive electric cars, we’ll need lots of energy.

  77. Ben McMillan says:

    Willard: that follows a conversation from another thread…

    At least in primary energy terms, renewable-powered EVs need about 1/5 as much energy as ICE vehicles.

    And the ratio is even bigger for 2/3 wheel urban vehicles that dominate the developing world and normally have inefficient small engines.

    But 2100 is pretty much sci-fi.

  78. Raypierre says:

    Hi,
    I feel sheepish about continuing to barge in here, since I thought I had sworn off blogs, but this is about the only place where there has been any intelligent discussion of the UN methane report, or the CO2 vs. CH4 issue more generally. In all the press coverage, almost nobody has bothered to contact me or Myles. The only press inquiry I have gotten so far is from Forbes, who seem to get the idea that the report doesn’t really represent a transformative moment in climate policy.

    For those who find the bottom line from the literature review one of the commenters above gave confusing I have this simple advice to offer: Intelligent methane policy can improve the climate situation some, but if that looks confusing or hard to do, just forget about it and concentrate on getting CO2 to netZero. It’s in line with Lord Nelson’s advice: If you’re feeling seasick//Sit underneath a tree.

    In one of Ken’s responses, he made reference to a claim that GWP* has the fault that it allows victory on emissions to be declared before net Zero CO2 emissions have been reached. This bit of nonsense derives from a bizarre argument in an article Joeri Rogelj wrote on the subject. Given that I don’t think Joeri is actually stupid, I can only attribute this to wilfully misconstruing the situation, probably in the hopes of preserving the IPCC status quo. The situation is that if there is a year in which methane emissions drop precipitously, you can — very transiently — have a situation where emissions of GWP* drop to zero. Joeri assumes that in this transient situation the Paris agreement would be instantly declared fulfilled, the agreement would be tossed on the bonfire, and everybody would go out and have a party. It’s no different from the situation in which the only metric is net Zero CO2 (my preference) and it was assumed the Paris Agreement was fulfilled the microsecond net Zero is touched, regardless of whether it is maintained at zero afterwards. GWP* emissions could hit zero only transiently, without CO2 emissions going to net Zero.

    That’s how bad the discourse has gotten. The foot-dragging and delays that ERL put us through trying to get some response to Joeri’s nonsense published (that includes the rather tortured claims on equity and grandfathering) is a very bad reflection on our field.

    (BTW, I changed the URL I’m listing here because I’m hoping some of you who need a break from climate physics will go there and check out the music, which is how I’ve been amusing myself while the pub sessions have been closed during lockdown. There’s a lot more there besides the Scandi stuff)

  79. Ray,

    I feel sheepish about continuing to barge in here, since I thought I had sworn off blogs, but this is about the only place where there has been any intelligent discussion of the UN methane report, or the CO2 vs. CH4 issue more generally.

    Thanks 🙂

    BTW, I changed the URL I’m listing here because I’m hoping some of you who need a break from climate physics will go there and check out the music, which is how I’ve been amusing myself while the pub sessions have been closed during lockdown.

    Well, I can say that I’ve seen you play live, so I can attest to it being well worth a listen.

  80. Willard says:

    Damn:

    The health risk for children from cooking with gas has been compared to that from living with a smoker.

    In a report into Australia’s reliance on gas released on Thursday, the Climate Council cites research that cooking with the fossil fuel is estimated to be responsible for 12 per cent of childhood asthma.
    It recommends that gas cooktops should be phased out in Victoria.

    https://www.theage.com.au/national/victoria/kids-asthma-risk-from-cooking-with-gas-like-living-with-a-smoker-20210505-p57p11.html

  81. Ben McMillan says:

    Also, once you’ve built a house with a gas connection, and wired up the kitchen, etc., it isn’t necessarily trivial to replace fossil gas appliances with electric (although easy enough if you are willing to compromise). Choice of heating matters too, and switching gas for a heat pump is not always easy/cheap, especially in places where building standard are poor and where people insist on hydronic heating (hello, UK).

    This stuff is a long-term commitment once built, so you can’t just ‘switch off’ fossil gas, it will take decades.

    The problem isn’t how long CH4 lasts up in the air, it is how long fossil gas infrastructure lives down on the surface.

    Worst case scenario we end up with lots of biogas and hydrogen from CCS, and CH4 emissions get worse, even though companies are being rewarded for low CO2 emissions.

    I.e. another ‘Dieselgate’ affair where we swap one pollutant for another.

  82. Raypierre says:

    @Ben I agree that the main problem with CH4 for cooking and home heating is that it is still a fossil fuel, and emits CO2 when burned. You certainly don’t need to look at CH4 vs CO2 metrics to justify the clear need to phase out CH4 for home heating (especially) and cooking (secondarily) if there is to be any hope of reaching net zero. Heat pumps powered by renewable electricity are the clear way to go, with variants in the kind of heat pump according to site. As you note, retrofitting heat pumps can be very expensive compared to being installed from the get-go. That’s why it’s so eye-wateringly stupid that the Tory building code has not imposed an immediate requirement on new-builds to install heat pumps, and has pushed the requirement off to 2025.

  83. Willard says:

    It might also be time for UK to revisit geothermal power:

    Geothermal energy development in the UK has been limited, partly due to the lack of high enthalpy resources, but also due to the availability of cheap fossil fuels. However, when comparisons are made to countries in a similar tectonic setting, it is clear that the UK is underutilizing this potential resource. The lack of geothermal development has largely been a result of the availability of North Sea natural gas during the 1980s and 1990s

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

    New housing development with geothermal heating is awesomesauce.

  84. Ben McMillan says:

    Doing some more geothermal in Iceland, and building a cable to the UK is potentially also a good option.

    Confusingly, USians refer to household ground-source heat pumps as ‘geothermal’, but the other side of the pond is normally talking about power stations using geothermal steam.

  85. jacksmith4tx says:

    My golden rule: Aim for maximum efficiency first and what ever energy source you use will go much farther. No matter what your energy source and what kind of technology you use (heat pumps, electric resistive heaters or natural gas) zoned heating and cooling will save the average consumer most energy while providing excellent comfort.
    I think these ‘smart vents’ would cut annual heating and cooling energy use by a huge amount.
    https://www.alealabs.com/
    https://keenhome.io/

  86. izen says:

    Meanwhile the FF companies are lobbying hard to retain the requirement to connect any new homes or commercial property built, to a natural gas pipeline. They are trying to keep, or instigate legislation that requires new build homes and commercial property to be connected to a fossil fuel source.

    https://www.motherjones.com/environment/2021/02/how-the-fossil-fuel-industry-convinced-americans-to-love-gas-stoves/
    “Wilson Truong posted on the Nextdoor social media platform—where users can send messages to a group in their neighborhood—… warned the group members that their city leaders were considering stronger building codes that would discourage natural gas lines in newly built homes and businesses. …He was writing in his role as account manager for the public relations firm Imprenta Communications Group. Imprenta’s client was Californians for Balanced Energy Solutions (C4BES), a front group for SoCalGas, the nation’s largest gas utility, working to fend off state initiatives to limit the future use of gas in buildings. C4BES had tasked Imprenta with exploring how social media platforms, including Nextdoor, could be used to foment community opposition to electrification.”

  87. Ben McMillan says:

    People who are targeting a Paris-compliant approach are correct to think that investment in long-lasting methane-emitting infrastructure is not compatible with this approach.

    That is, even when switching to fossil gas is an improvement over old coal, it is still a not-good-enough half measure.

    The gas industry seems keen on making an end-run around CO2 regulation by doing carbon capture and storage, e.g. hydrogen-from-gas-with-CCS. Or at least promising this to prevent gas looking like a complete dead-end.

    Australia is talking about hydrogen-from-brown-coal-with-CCS which pretty much takes the prize for horrible ideas.

  88. Willard says:

    The hydrogen market may rise in the near future:

    At the request of the government of Japan under its G20 presidency, the International Energy Agency produced this landmark report to analyse the current state of play for hydrogen and to offer guidance on its future development.

    The report finds that clean hydrogen is currently enjoying unprecedented political and business momentum, with the number of policies and projects around the world expanding rapidly. It concludes that now is the time to scale up technologies and bring down costs to allow hydrogen to become widely used. The pragmatic and actionable recommendations to governments and industry that are provided will make it possible to take full advantage of this increasing momentum.

    https://www.iea.org/reports/the-future-of-hydrogen

    From the report itself:

    Today, much of the refining and chemicals production that uses hydrogen based on fossil fuels is already concentrated in coastal industrial zones around the world, such as the North Sea in Europe, the Gulf Coast in North America and southeastern China. Encouraging these plants to shift to cleaner hydrogen production would drive down overall costs. These large sources of hydrogen supply can also fuel ships and trucks serving the ports and power other nearby industrial facilities like steel plants.

    Usual qualifiers apply: not an investment advice, markets are volatile, etc.

  89. Russell says:

    Hydrogen, the transportation fuel of the future ,since 1785, when Pilâtre de Rozier came to grief trying to fly the Channel in a hybrid hydrogen-hot air balloon.

    That great Green refrigerant, ammonia enjoyed a brief vogue a century ago, until the exploding cold storage facility death toll caught up with the Hindenburg.

  90. Ben McMillan says:

    The neat thing about hydrogen from the fossil gas industry point of view is that you don’t have to produce any for it to be useful. You just hold it out as an option, as a way to reuse all the existing infrastructure (with ‘minor’ modification) and delay the need for direct electrification.

    Reminds me of when the fossil generators were talking about building ‘CCS-ready’ plants.

    Probably e-fuels have a role to play, but if we’re going to end up with hydrogen-from-gas, the fugitive emissions of CH4 could be very high.

  91. Dave_Geologist says:

    Actually I think the problem was more with the ammonia being poisonous than it being flammable, and domestic consumers, who didn’t undertake the sort of precautions, inspections and maintenance procedures (which of course sometimes failed) that commercial operators did, succumbing with their family.

    Einstein’s Fridge

  92. Willard says:

    I heard good things about trinitrotoluene, benzol, and picric acid:

  93. David B Benson says:

    https://bravenewclimate.proboards.com/thread/553/open-thread?page=8
    Notice the full attention to methane in order to limit warming to 1.5 °C. — According to the Potsdam Institute.

  94. Russell says:

    Dave might have mentioned that Einstein’s patented workaround for the leaky toxic refrigerator problem was to replace the leaky ammonia compressor piston with a multi-kilogram column of a very heavy liquid.

    Mercury to be exact

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