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2020 vision

A meeting of smoke and storms (NASA Earth Observatory)

No-one needs another litany of all the terrible things that happened this year, but there are three areas relevant to climate science that are worth thinking about:

  • What actually happened in climate/weather (and how they can be teased apart). There is a good summary on the BBC radio Discover program covering wildfires, heat waves, Arctic sea ice, the hurricane season, etc. featuring Mike Mann, Nerlie Abram, Sarah Perkins-Kilpatrick, Steve Vavrus and others. In particular, there were also some new analyses of hurricanes (their rapid intensification, slowing, greater precipitation levels etc.), as well as the expanding season for tropical storms that may have climate change components. Yale Climate Connections also has a good summary.
  • The accumulation of CMIP6 results. We discussed some aspects of these results extensively – notably the increased spread in Equilibrium Climate Sensitivity, but there is a lot more work to be done on analyzing the still-growing database that will dominate the discussion of climate projections for the next few years. Of particular note will be the need for more sophisticated analyses of these model simulations that take into account observational constraints on ECS and a wider range of future scenarios (beyond just the SSP marker scenarios that were used in CMIP). These issues will be key for the upcoming IPCC 6th Assessment Report and the next National Climate Assessment.
  • The intersection of climate and Covid-19.
    • The direct connections are clear – massive changes in emissions of aerosols, short-lived polluting gases (like NOx) and CO2 – mainly from reductions in transportation. Initial results demonstrated a clear connection between cleaner air and the pandemic-related restrictions and behavioural changes, but so far the impacts on temperature or other climate variables appear to be too small to detect (Freidlingstein et al, 2020). The impact on global CO2 emissions (LeQuere et al, 2020) has been large (about 10% globally) – but not enough to stop CO2 concentrations from continuing to rise (that would need a reduction of more like 70-80%). Since the impact from CO2 is cumulative this won’t make a big difference in future temperatures unless it is sustained through post-pandemic changes.
    • The metaphorical connections are also clear. The instant rise of corona virus-denialism, the propagation of fringe viewpoints from once notable scientists, petitions to undermine mainstream epidemiology, politicized science communications, and the difficulty in matching policy to science (even for politicians who want to just ‘follow the science’), all seem instantly recognizable from a climate change perspective. The notion that climate change was a uniquely wicked problem (because of it’s long term and global nature) has evaporated as quickly as John Ioannidis’ credibility.

I need to take time to note that there has been human toll of Covid-19 on climate science, ranging from the famous (John Houghton) to the families of people you never hear about in the press but whose work underpins the data collection, analysis and understanding we all rely on. This was/is a singular tragedy.

With the La Niña now peaking in the tropical Pacific, we can expect a slightly cooler year in 2021 and perhaps a different character of weather events, though the long-term trends will persist. My hope is that the cracks in the system that 2020 has revealed (across a swathe of issues) can serve as an motivation to improve resilience, equity and planning, across the board. That might well be the most important climate impact of all.

A happier new year to you all.


  1. P.M. Forster, H.I. Forster, M.J. Evans, M.J. Gidden, C.D. Jones, C.A. Keller, R.D. Lamboll, C.L. Quéré, J. Rogelj, D. Rosen, C. Schleussner, T.B. Richardson, C.J. Smith, and S.T. Turnock, "Current and future global climate impacts resulting from COVID-19", Nature Climate Change, vol. 10, pp. 913-919, 2020.
  2. C. Le Quéré, R.B. Jackson, M.W. Jones, A.J.P. Smith, S. Abernethy, R.M. Andrew, A.J. De-Gol, D.R. Willis, Y. Shan, J.G. Canadell, P. Friedlingstein, F. Creutzig, and G.P. Peters, "Temporary reduction in daily global CO2 emissions during the COVID-19 forced confinement", Nature Climate Change, vol. 10, pp. 647-653, 2020.

26 Responses to “2020 vision”

  1. 1
    mike says:

    great graphic on the smoke and storms! Thanks for that, wishing a happy new year to the scientists working on this website.

  2. 2

    Thanks, Gavin, and let me both return and second your New Year’s wish!

    Covid denialism has been both instructive and chilling.

  3. 3
    John Mashey says:

    Another climate-related loss to COVID this year was a friend of ours, Don Kennedy, who as Editor-in-Chief of Science, was very supportive of climate science:

    He took me to lunch one time at Stanford to talk about climate science support activities. I used to visit him in nursing home he’d moved to.
    Richard Alley sent me a set of photos of expeditions, which I took to Don and he enjoyed.

  4. 4
    CM says:

    A happier new year to you, too. And may the return of grown-ups to government speed the solutions to both crises.

  5. 5
    Silvia Leahu-Aluas says:

    Thank you, Gavin. Happy, Rational, Healthy, Respectful New Year to all of you at RealClimate, to all good scientists and to everybody, including the obscurantists, as the majority of them don’t know what they are doing. For those who do, let’s get them out of any decision-making position.

    Let’s also make sure that the return of competent government in the US will mean urgent, consequential, enduring action, in solving the current pandemic, the climate emergency and all the other crises caused by and/or affecting our society and the human civilization.

    We need accomplishments. I would like to see a clear target for US GHG emission (both direct and indirect, no damage “outsourcing”)reduction in 2021. On the same day, a year from now, it would be useful to see that goal achieved or surpassed.

  6. 6
    james says:

    I just listened to Mann talking on the BBC podcast and was taken about to hear him sprout rubbish, which I think would be fuel for the denier set:

    “methane is a potent greenhouse gas, molecule for molecule more powerful than CO2 …”. It is not and I would expect him to even briefly explain why it appears to be more potent than CO2

    and a little later

    “tropical storms get their energy from evaporation …”
    2256 kJ per kilogram at 100C sinked not sourced !

    come on sir …

  7. 7
    barry says:

    Sorry to hear about John Houghton. I never met him, but I did meet a student of his who revered him.

    Does anyone know if Grant Foster is ok? He hasn’t posted at Open Mind since July.

  8. 8
    jgnfld says:

    @6 re. “It is not and I would expect him to even briefly explain why it appears to be more potent than CO2”

    Actually it IS on a molecule by molecule basis. Just like Mann stated. Perhaps you didn’t read/comprehend the words “molecule by molecule”? About 25-30X times or so more potent.

    It is also such a completely fundamental fact that it doesn’t need mentioning in any even semiscientific context. It’s taught right down into the high school level. You must have missed the memo. It’s like a sports fan being “confused” about the differences between a softball game and hardball game. It’s simply common knowledge. You have nothing to offer in a sports discussion if you don’t know anything about the games. Same in science.

    Short primer here with links to more detail should you be up to it: . More deeper-but still-primer-level details here: . As well there is much more provided in the refs and links in both entries.

    Bear in mind this is the Trump-led EPA site.

    Anyway, if you are interested there is a great amount of actual, researched material out there if you are interested. Learning is incredibly rewarding–though does require skull sweat. Isn’t that a LOT more interesting than spouting propaganda?

  9. 9
    Susan Anderson says:

    Knew about Houghton

    I’m sorry to report that a friend who tried to contact Grant Foster and got no reply, so I doubt that has a good answer.

    Al Bundy, this is a long overdue apology for going too far. This is short, but I mean it!

    With regard to the New Year, all the best to everyone (this won’t be posted until tomorrow at the earliest). My best friend and I were discussing the transition from 2020 to 2021, about which I am not optimistic, though some of the signs are positive. Particular attention needs to be paid to the circular firing squads, as some of the US progressive wing leaders are already bashing Biden (whose choices, I think, are excellent). Here’s what we came up with:

    Lousy is better than horrible. It’s a step towards better. Don’t knock it!

    Here’s to recognizing that fireworks, fancy displays, rock concerts, and more stuff are obvious low hanging fruit in the fight towards having a future.

    I know it sounds horrid, but honesty being the best policy, let’s stop bashing our friends and support them in recognizing that compromise, while not enough, is necessary on the road to getting communities to care about everybody and make progress.

    While you’re at it, please support women, if you think population control is essential. Empowering women leads to fewer children and better policy. Your witnesses, New Zealand’s Jacinda Ardern, Finland’s Sanna Marin, Michigan’s Gretchen Whitmer, and Germany’s Angela Merkel (with apologies to Kamala Harris, who is also a good influence). As custodians of humanity, the women seem to be, on the whole, less preoccupied with immediate benefits and more concerned about the future

  10. 10
    Dan says:

    ““methane is a potent greenhouse gas, molecule for molecule more powerful than CO2 …”. It is not and I would expect him to even briefly explain why it appears to be more potent than CO2”

    What pure anti-science rubbish that comment is. FYI, In 2013, the Intergovernmental Panel on Climate Change (IPCC) reported, based on peer-reviewed science (the way science has been conducted for centuries) that methane is a far more potent greenhouse gas than had been previously assumed. The IPCC calculated that methane is 34 times stronger as a heat-trapping gas than CO2 over a 100-year time scale.

    So you think you know more than literally every professional climate science organization in the world? Let alone, your lack of knowledge of thermodynamics. smh

  11. 11
    james says:

    Dan perhaps you would look at the temperature rise caused by a doubling of concentration of a greenhouse gas. NASA says (and this number is important) that CO2 is cica 2.6C whereas methane is about HALF that.
    But if you add 1 glob CO2 to the atmosphere taking us from (say) 410 to 416 ppm CO2 the effect is slight. If you add the same sized glob of methane taking us (say) from 2ppm to 8 ppm then the effect is huge (say 2.5C).
    And the 1/2 life of methane is 10 years so methane is inconvenient but CO2 is the real enemy.

  12. 12
    Piotr says:

    James (6): “ I just listened to Mann talking on the BBC podcast and was taken about to hear him sprout rubbish: “methane is a potent greenhouse gas, molecule for molecule more powerful than CO2 …”. It is not and I would expect him to even briefly explain why it appears to be more potent than CO2 […] come on sir …

    Strong claims (Mann “sprouting rubbish”) demand strong proofs. Yours (your certian of yourself: “it is not”). Particularly that it does not take a genius to check your arrogant claims with facts – it would have been enough if you … copied and pasted your own phrase into Google Search:

    and voila: page after page of hits explaining why “ methane, molecule for molecule, more powerful greenhouse gas than CO2“. Heck, there is even a special term to quantify HOW MUCH more powerful: “GWP” (“Global Warming Potential”).

    P.S. Does your: “ which I think would be fuel for the denier set” suggests that you are … NOT a part of that set??? If so, please correct it – your arrogant ignorance makes you a natural match over there, here people will expect you to learn before “sprouting” full of yourself opinions…

  13. 13
    Ray Ladbury says:

    A caution on methane
    1) It’s greenhouse potential is significantly larger than CO2 because it is in lower concentrations, so adding more of it blocks light in the absorption peak and not its wings–as does additional CO2.
    2) Because of this, how much of an issue it is depends on how much you add.
    3) Yes, CH4 breaks down to CO2 and water vapor after some time–but that time depends on how much CO2 is in the atmosphere. The breakdown mechanism has a finite capacity, and if you add enough CH4, it can take longer for it to break down.
    4) You need to consider feedbacks and tipping points–more rapid warming, even if it is only temporary could have a disproportionate effect that might not allow us to get back where we were after the CH4 is removed.

  14. 14
    Dan says:

    re: 11. Once again, I refer you to the IPCC 2013 Report, based on actual peer-reviewed science. As you even said, the same amount of methane is “huge”.
    From (I have left out the specific references but they are peer-reviewed):

    “The direct radiative greenhouse gas forcing effect has been estimated at 0.5 W/m2.[103]”

    (Note the *potency* if you will over time; it is still 28 times more so than CO2 for 100 years:) “Methane is a strong GHG with a global warming potential 84 times greater than CO2 in a 20-year time frame. Methane is not as persistent a gas and tails off to about 28 times greater than CO2 for a 100-year time frame.”

    “In addition to the direct heating effect and the normal feedbacks, the methane breaks down to carbon dioxide and water. This water is often above the tropopause where little water usually reaches. Ramanathan (1988)[105] notes that both water and ice clouds, when formed at cold lower stratospheric temperatures, are extremely efficient in enhancing the atmospheric greenhouse effect. He also notes that there is a distinct possibility that large increases in future methane may lead to a surface warming that increases nonlinearly with the methane concentration.”

  15. 15
    james says:

    I accept without reservation and I think Ray puts the issue succinctly.
    My comment was more along the lines of I wish that Mann (who I do respect, heck I’ve even bought some of his books, and who was on Question and Answer in Australia a year ago and gave lovely answers) had used Ladbury’s more detailed explanation.
    I think the great unwashed can come away thinking evaporation provides the energy for a tropical storm rather than it being the transfer mechanism to get energy from the sea to the clouds.
    I guess this highlights the difficulty of explaining complex issues to a lay audience.
    For example if you release 1 glob of methane once then after 100 years the effect is gone (complicated by CO2 and tropospheric H2O)
    The IPCC report sotto voces the bit that says you can’t release methane once then stop. So they are correct in a round about way.
    Finally am I a denier? I had a junk phone call ‘Do you believe in Global Warming?’ No! I understand the physics. Belief is irrelevant.
    Mr Mann if my critique offended then I am sorry (much more sincere than offering appologies)

  16. 16
    Piotr says:

    James (15): “Finally am I a denier?”
    By their fruits you shall know them: “ I just listened to Mann talking on the BBC podcast and was taken about to hear him sprout rubbish: “methane is a potent greenhouse gas, molecule for molecule more powerful than CO2 …”. It is not […] come on sir …” James(6).

    James(15): “No! I understand the physics” By their fruits you shall know them: [See above and below]

    James(15): “Belief is irrelevant” And nobody evaluated you here based on your?our? beliefs, but on your arguments. By their fruits you shall know them. [See below:]

    James(15): “if you release 1 glob of methane once then after 100 years the effect is gone “.

    Not necessarily – if it is “gone” by oxidation to CO2 – then it is not gone, but still there as extra CO2. And if it was gone by reaction that resulted in creation of Ozone, then it is still there as the effect of that extra ozone.

    And the different rates of “being gone” between CH4 and CO2 are already included in the values of the GWP: :
    – over “100 years”, your “1 glob of CH4” has the same effect as …28-34 “globs of CO2”
    – over 20 years – “1 glob of CH4” has the same effect as 84-86 globs of CO2. (And for most of policy decisions probably the 20-yr time scale is much more relevant than your 100-yr one).
    – instantaneous GWP of CH4 would be HIGHER STILL. And to some, like P. Nightingale (2018), “Only the instantaneous global warming potential is consistent with honest and responsible greenhouse gas accounting”.

    But regardless which of these time scales you chose: “methane is a potent greenhouse gas, molecule for molecule more powerful than CO2 …”

    So much for your, informed by your “No! I understand the physics“,argument:

    just listened to Mann talking on the BBC podcast and was taken about to hear him sprout rubbish: “methane is a potent greenhouse gas, molecule for molecule more powerful than CO2 …”. It is not […] come on sir …

  17. 17

    Grant Foster is alive.

  18. 18
    james says:

    Victor I fear we are wasting resources arguing different issues, we should stop.
    If you measured methane vs CO2 on venus or mars or even the moon you’d get different answers! It is conceivable (but terrifing) that we could reach 800 ppm CO2 in 100 years. If we did the IPCC 100 year estimates of the effect of CH4 would be too small.
    Likewise if the fairy waved her wand and removed a chunk of CO2, CO2 would appear stronger and methane weaker.
    Maybe MM is correct: the details don’t matter, the idea does.

  19. 19
  20. 20
    mike says:

    very happy to hear that Grant Foster is alive. I hope he is well and resumes blogging in 2021. His math work is stellar.


  21. 21
    Piotr says:

    James(19) An interesting link

    … with all the calculations there done with the understanding of the fact that molecule per molecule, CH4 has MANY TIMES higher effect than CO2. I.e. CONTRADICTING your original claims in this thread

    I just listened to Mann talking on the BBC podcast and was taken about to hear him sprout rubbish: “methane is a potent greenhouse gas, molecule for molecule more powerful than CO2 …”. It is not […] come on sir …” James(6)

    and: “No! I understand the physics” James(15)

  22. 22
    james says:

    Self critical: Am I sprouting rubbish?

    I said

    For example if you release 1 glob of methane once then after 100 years the effect is gone (complicated by CO2 and tropospheric H2O)

    And look at his 100 year (modeled) rates

    I thought the temperature rise for a doubling of CH4 concentration was cica 1.3 C
    I can’t find any reputable reference for example they suggest 0.08 C (methane is 1 / 30 as strong as CO2) but that seems wrong and I can’t confirm. Is anyone able to give me a ref please?

  23. 23

    P 21,

    The many-times-higher effect of CH4 compared to CO2 depends on the fact that CH4 is a minority trace gas operating near the main infrared window, while CO2 is present in much greater amounts over a much wider range of wavelengths. The absorption coefficients for each, at 1 atmosphere and 288 K, are roughly as follows:

    2.2-2.5 microns, 147 m^2 kg^-1
    3.5-4.5, 18.0
    6.5-7.0, 3.2

    1.9-2.1, 334
    2.6-2.9, 71
    4.1-4.5, 9.356
    13.235-13.545, 0.17
    13.545-14, 0.82
    14-16, 20
    16-16.66, 0.88

    On that basis, it’s hard to decide which is “stronger.” It’s safe to say that under present Earth conditions, with 0.18 ppmv of methane and 415 ppmv of CO2, a proportionate increase in methane should cause more warming.

  24. 24
    Western Hiker says:

    Susan Anderson, #9

    We should add Stacey Abrams to your list.
    Thank you, Georgia!

  25. 25
    Susan Anderson says:

    Stacey Abrams, indeed, my hero today. [and what a day it was, nuff said]

    VV, thanks, glad to hear that. His former neighbor said he had moved (California?) and they’d lost touch; I’ll let him know. I miss Tamino’s Open Mind posts.

  26. 26
    james says:

    Thank you for the info Barton (is Barton Paul Levenson the correct salutation)
    Mr Mann my criticism was hasty and ill considered.
    My friend, who did much better at uni than I, and who in Mr Mann’s words: has a mind so open his brain has fallen out, seized on the pod cast with glee to tell me CO2 was not important but methane was according to the experts.
    The beast is dead, the point is made, I am sorry.