A climate science milestone: a successful 10-year forecast!

Summary:  The gridlock might be breaking in the public policy response to climate change. This gridlock has left us unprepared for even the inevitable repeat of past extreme weather — let alone what new challenges the future will hold for us. Here is the good news plus some simple measures that can decisively break open the policy debate.

Science Technology

The below graph was tweeted yesterday by Gavin Schmidt, Director of NASA’s Goddard Institute of Space Sciences (click to enlarge). (Yesterday Zeke Hausfather at Carbon Brief posted a similar graph.) This shows surface atmosphere temperatures. It is another step forward in the public policy debate about climate change, in two ways.

Gavin graph of temperature observations vs. CMIP3 models

(1)  This graph shows a climate model’s demonstration of predictive skill over a short time horizon of roughly ten years. CMIP3 was prepared in 2006-7 for the IPCC’s AR4 report. That’s progress, a milestone — a successful decade-long forecast!  {Note: I start the clock when the model is run, as is done in other fields. Not when the model is initialized. This eliminates concern about “tuning” the model to better match past observations. When it comes to high stakes politics, “Caesar’s wife must be above suspicion.“}

(2) The graph uses basic statistics, something too rarely seen today in meteorology and climate science. For example, the descriptions of Hurricanes Harvey and Irma were very 19th C, as if modern statistics had not been invented. Compare Schmidt’s graph with Climate Lab Book’s updated version of the signature “spaghetti” graph — Figure 11.25a — from the IPCC’s AR5 Working Group I report (click to enlarge). Edward Tufte (The Visual Display of Quantitative Information) weeps every time someone posts a spaghetti graph.

ClimateLab: temperature observations vs. CMIP3 model
Updated IPCC AR5 Figure 11.25a, showing observations and the CMIP5 model projections relative to 1986-2005. The black lines are observational datasets (HadCRUT4.5, Cowtan & Way, NASA GISTEMP, NOAA GlobalTemp, BEST).

Note how the graphs differ in the display of the difference between observations and CMIP3 model output during 2005-2010. Schmidt’s graph shows that observations are near the ensemble mean. The updated Figure 11.25a shows observations near the bottom of the range of CMIP5 model outputs (Schmidt also provides his graph using CMIP5 model outputs).

Clearing away the underbrush so we can see the big issues.

This is one in a series of recent incremental steps forward in the climate change policy debate. Here are two more examples of clearing away relatively minor issues. Even baby steps add up.

(1) Ocean heat content (OHC) as the best metric of warming.

This was controversial when Roger Pielke Sr. first said it in 2003 (despite his eminent record, Skeptical Science called him a “climate misinformer” – for bogus reasons). Now many climate scientists consider OHC to be the best measure of global warming. Some point to changes in the ocean’s heat content as an explanation for the pause.

Graphs of OHC should convert any remaining deniers of global warming (there are some out there). This shows the increasing OHC of the top 700 meters of the oceans, from NOAA’s OHC page. See here for more information about the increase in OHC.

Graph of ocean heat content from NOAA

(2)  The end of the “pause” or “hiatus”.

Global atmospheric temperatures paused during period roughly between the 1998 and 2016 El Ninos, especially according to the contemporaneous records (later adjustments slightly changed the picture). Activists said that the pause was an invention of deniers. To do so they had to conceal the scores of peer-reviewed papers identifying the pause, exploring its causes (there is still no consensus on this), and forecasting when it would end. They were quite successful at this, with the help of their journalist-accomplices.

Now that is behind us. As the below graph shows, atmospheric temperatures appear (tentative) to have resumed their increase, or taken a new stair step up — as described in “Reconciling the signal and noise of atmospheric warming on decadal timescales“, Roger N. Jones and James H. Ricketts, Earth System Dynamics, 8 (1), 2017. Click to enlarge the graph.

Global Surface Temperature from NOAA

What next in the public policy debate about climate change?

Perhaps now we can focus on the important issues. Here are my nominees for the two most important open issues.

(1) Validating climate models as providers of skillful long-term projections.

The key question has always been about future climate change. How will different aspects of weather change, at what rate? Climate models provide these answers. But acceptable standards of accuracy and reliability differ for scientists doing research and leaders making policy decisions affecting billions of people and the course of the global economy. We have limited resources; the list of threats is long (e.g., the oceans are dying). We need hard answers.

There has been astonishingly little work addressing this vital question. See major scientists discussing the need to do so. We have the tools to do so. A multidisciplinary team of experts (e.g., software engineers, statisticians, chemists), adequately funded, could do so in a year. Here is a proposal: Climate scientists can restart the climate policy debate & win: test the models! That post also lists (with links) the major papers in the literature about validation of climate models.

There is a strong literature to draw on about how to test theories and computer models. Let’s use it. This could be a game-changer.

  1. Thomas Kuhn tells us what we need to know about climate science.
  2. Daniel Davies’ insights about predictions can unlock the climate change debate.
  3. Karl Popper explains how to open the deadlocked climate policy debate.
  4. Milton Friedman’s advice about restarting the climate policy debate.
  5. Paul Krugman talks about economics. Climate scientists can learn from his insights.
  6. We must rely on forecasts by computer models. Are they reliable? (Many citations.)
  7. Paul Krugman explains how to break the climate policy deadlock.

Climate Change Choices

(2) Modeling forcers of climate change (greenhouse gases, land use).

Climate models forecast climate based on the input of scenarios describing the world. This includes factors such as amounts of the major greenhouse gases there are in the atmosphere. These scenarios have improved in detail and sophistication in each IPCC report, but they remain an inadequate basis for making public policy.

The obvious missing element is a “business as usual” or baseline scenario. AR5 used four scenarios — Representative Concentration Pathways (RCPs). The worst was RCP8.5 — an ugly scenario of technological stagnation and rapid population growth, in which coal becomes the dominant fuel of the late 21st century (as it was in the late 19th C). Unfortunately, “despite not being explicitly designed as business as usual or mitigation scenarios” RCP8.5 has often been misrepresented as the “business as usual” scenario — becoming the basis for hundreds of predictions about our certain doom from climate change. Only recently have scientists began shifting their attention to more realistic scenarios.

A basecase scenario would provide a useful basis for public policy. Also useful would be a scenario with likely continued progress in energy technology and continued declines in world fertility (e.g., we will get a contraceptive pill for men, eventually). That would show policy-makers and the public the possible rewards for policies that encourage these trends.

Cover of "Turning the Tide On Climate Change" by Robert Kandel
“Turning the Tide On Climate Change” by Robert Kandel (2009). Wikipedia Commons.

Conclusions

Science and public policy both usually advance by baby steps, incremental changes that can accomplish great things over time. But we can do better. Since 2009 my recommendations have been the same about our public policy response to climate change. After three decades of policy gridlock, we should try different approaches.

  1. More funding for climate sciences. Many key aspects (e.g., global temperature data collection and analysis) are grossly underfunded compared to their importance.
  2. Run government-funded climate research with tighter standards (e.g., posting of data and methods, review by unaffiliated experts), just as we do for biomedical research.
  3. Fund a review of the climate forecasting models by a multidisciplinary team of relevant experts who have not been central players in this debate. Include a broader pool of experts than those who have dominated the field, such as geologists, chemists, statisticians and software engineers.
  4. We should begin a well-funded conversion to non-carbon-based energy sources, for completion by the second half of the 21st century — justified by both environmental and economic reasons (see these posts for details).
  5. Begin more aggressive efforts to prepare for extreme climate. We’re not prepared for repeat of past extreme weather (e.g., a major hurricane hitting NYC), let alone predictable climate change (e.g., sea levels climbing, as they have for thousands of years).
  6. The most important one: break the gridlocked public policy by running a fair test of the climate models.

For More Information

For more about the close agreement of short-term climate model temperature forecasts with observations, see “Factcheck: Climate models have not ‘exaggerated’ global warming” by Zeke Hausfather at Carbon Brief. To learn more about the state of climate change see The Rightful Place of Science: Disasters and Climate Change by Roger Pielke Jr. (Prof of Environmental Studies at U of CO-Boulder).

If you liked this post, like us on Facebook and follow us on Twitter. For more information see all posts about the IPCC, see the keys to understanding climate change and these posts about the politics of climate change…

A fun debunking of a climate propaganda story.

Polar Bears: Outstanding Survivors of Climate Change
Available at Amazon.

Polar Bears: Outstanding Survivors of Climate Change by Susan J. Crawford. From the publisher…

This book explains why polar bears are thriving despite the recent decline of Arctic sea ice. It describes polar bears’ ecology and conservation issues, providing up-to-date information in an easy to digest format — fully referenced. It is the book giving the science about polar bears that people have been requesting.

Contents — Polar bear & sea ice basics. Feasting and fasting, the life of polar bears. Evolution & climate change. Conservation & protection. Failure of the polar bear predictions. The biggest threat to polar bears. Summary and conclusions.

Susan Crockford is a zoologist with more than 35 years of experience, including published work on the Holocene history of Arctic animals. She is an adjunct professor at the University of Victoria, British Columbia (a “non-remunerated professional zooarcheologist associate”) and co-owner of a private consulting company, Pacific Identifications Inc. See her publications and her website Polar Bear Science. She has also written a novel, Eaten — a polar bear attack thriller.

 

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46 thoughts on “A climate science milestone: a successful 10-year forecast!

  1. There seem to be some scientific voices saying that the models were running too hot and the Paris stretch goal may be more easily achieved than we thought. The actual study seems to be hiding behind pay walls but here’s WaPo about it: https://www.washingtonpost.com/news/energy-environment/wp/2017/09/18/new-climate-calculations-could-buy-the-earth-some-time-if-theyre-right/?utm_term=.fb16e36adbb6 – you may be able to get a better link.

    The basic thrust seems to be that if current trend continues we’ll miss the doom barrier with time to spare. So that’s good, even if it doesn’t mash the dopamine buttons in our brains as hard.

    Liked by 2 people

    1. SF,

      That’s the study Zeke discussed in his new paper at Carbon Brief. The lesson for public policy from the Miller paper in Nature Geoscience is, imo, that these forecasts are on the frontier of climate science. For example, see the wide range of estimates for the key factors transient climate response (TCR) and equilibrium climate sensitivity (ECS).

      Lots of interesting work being done, but this makes their conclusions a weak basis for public policy at this time. Hence the need for more work on model validation.

      Like

    2. Climate alarmists have finally admitted that they’ve got it wrong on global warming.

      This is the inescapable conclusion of a landmark paper, published in Nature Geoscience, which finally admits that the computer models have overstated the impact of carbon dioxide on climate and that the planet is warming more slowly than predicted.

      The paper – titled Emission budgets and pathways consistent with limiting warming to 1.5 °C – concedes that it is now almost impossible that the doomsday predictions made in the last IPCC Assessment Report of 1.5 degrees C warming above pre-industrial levels by 2022 will come true.

      For that to happen, temperatures would have to rise by a massive 0.5 degrees C in five years.

      Since global mean temperatures rarely rise by even as much as 0.25 degrees C in a decade, that would mean the planet would have to do 20 years’ worth of extreme warming in the space of the next five years.

      This, the scientists admit, is next to impossible. Which means their “carbon budget” – the amount of CO2 they say is needed to increase global warming by a certain degree – is wrong. This in turn means that the computer models they’ve been using to scare the world with tales of man-made climate doom are wrong too.

      One researcher – from the alarmist side of the argument, not the skeptical one – has described the paper’s conclusion as “breathtaking” in its implications.

      He’s right. The scientists who’ve written this paper aren’t climate skeptics. They’re longstanding warmists, implacable foes of climate skeptics, and they’re also actually the people responsible for producing the IPCC’s carbon budget.

      In other words, this represents the most massive climbdown from the alarmist camp.

      But you certainly wouldn’t guess this from the way the scientists are trying to spin their report.

      Like

    3. B.A. Farrar,

      I just got around to downloading it, so I can’t say anything about it. However — note that the lead author has been (to give my subjective interpretation) “frantically” back-pedalling on the interpretations of this paper. A tentative (I haven’t read much about this) possibility is that he unintentionally committed heresy against the paradigm. The reaction has been, of course, severe.

      I strongly recommend against drawing premature conclusions about these technical matters. The first reactions often prove incorrect.

      I even more strongly recommend against putting to much weight on one paper. This is called “single-study syndrome”.

      “I’ve written here before about what I call “single-study syndrome,” the habit of the more aggressive camps of advocates surrounding hot issues (e.g., climate, chemical exposure, fracking) to latch onto and push studies supporting an agenda, no matter how tenuous — or dubious — the research might be.”

      Andrew Revkin, NYT journalist.

      Like

    4. BAF,

      Miller and a co-author have responded to the (as usual) bogus comments about their paper: “When media sceptics misrepresent our climate research we must speak out” by Myles Allen and Richard Millar in The Guardian, 21 September 2017 — “Our climate paper underlined that strong action towards the 1.5C Paris goal is perhaps more valid than ever, but reading some of the media coverage you might think the opposite was true.”

      As I warned, media coverage often misrepresents new research.

      Like

    5. Alarm about alarmism – https://judithcurry.com/2017/07/15/alarm-about-alarmism/ – The comments are very interesting too – for the most part by other scientists.

      You may enjoy this quote within the article: “A few other articles with interesting points:

      Fabius Maximus: After 30 years of failure to gain support of the US public for massive public policy measures to fight climate change, climate activists now double down on the tactics that have failed them for so long. This post explains why it will not work. Nor should it. Instead they should trust the IPCC and science, showing both the good and bad news.

      SF Chronicle: If you honestly believe that climate change will end all life on Earth (it won’t) or lead to some dystopian hell, what policies wouldn’t you endorse to stop it?

      FYI – My style is never to rely on one report any more than I would rely on the failed climate models. My effort is to read all the peer reviewed articles and those who aren’t but are done by life-long climate scientists such as Roy Spencer, Judith Curry, Jo Nova, as well as many other scientists. The expertise contained in Roy Spencers career is phenominal and the comments are very enlightening on both Spencer and Curry’s articles. Their articles are replete with sources from other scientists and are very informative.

      Like

    6. It is always uncomfortable when what we thought was correct actually isn’t/wasn’t. It’s always best to read all the climate scientists to find the truth. I’ve read several articles later than says the climate is not nearly as sensitive as once thought. Even the UN’s IPCC confirms that truth.

      Like

    7. BAF,

      “It’s always best to read all the climate scientists to find the truth. ”

      First, I’m skeptical about laypeople’s ability to read science literature. I’ve had hundreds of conversations in the decade I’ve written about climate change, and for most it has been an exercise in confirmation bias. I recommend that most people stick to the reports for the public by the IPCC and major climate agencies.

      Second, I don’t know how many people it would take working full time to read all the peer-reviewed climate science literature and publications of the major climate agencies. Ten?

      Third, I’m far more familiar with it than most laypeople (both for writing here and in my business), and I understand only a small fraction of it.

      Like

    8. You might be comforted to know that I’ve been studying climate science for over 10 years. My study started when Al Gore scared me half to death and wanted to see what I could do to help save my family from immentently burning to death. Then there was ClimateGate 1, 2, and 3 not to mention the fact that the climate models have not be right one single time – not even close. Gradually after reading many great scientists, I’ve become weary of the conjecture being called facts. Just a guess, but could you be guilty of a little confirmation bias.

      The UN’s IPCC has been wrong several times and uses a lot of vague language in their reports some might call disclaimers if things aren’t what they say they are. As we all know when garbage goes into the climate models, garbage comes out. There is no way they know enough about how the climate works to know what the solutions should be or if there is any kind of real problem as it concerns CO2. The scientists don’t know how much of the CO2 is naturally occurring or how much is man-caused. How could they with all the seeping under the oceans. Most of the information seems to be conjecture upon conjecture and that is not science. Correlation is not causation, the weather is not climate, and CO2 is not CO.

      The climate scientist who created the satellites such as Roy Spencer and a renown climate scientist like Judith Curry are most likely as good if not better than those at the UN’s science organization. The scientists who do studies on this site http://co2science.org/ are very informative.

      Sorry – but the science has become too politically driven and most everyone who reads what the scientists have to say (and I talk to some of them daily) knows the group think has hurt their profession.

      This is what is needed – A ‘Red Team’ Exercise Would Strengthen Climate Science – https://judithcurry.com/2017/04/21/a-red-team-exercise-would-strengthen-climate-science/ – If the science is settled then let’s get the facts out in the open. The science is not settled. Science is inherently skeptical.

      BTW – About Roy Spencer: ”

      Roy W. Spencer received his Ph.D. in meteorology at the University of Wisconsin-Madison in 1981. Before becoming a Principal Research Scientist at the University of Alabama in Huntsville in 2001, he was a Senior Scientist for Climate Studies at NASA’s Marshall Space Flight Center, where he and Dr. John Christy received NASA’s Exceptional Scientific Achievement Medal for their global temperature monitoring work with satellites. Dr. Spencer’s work with NASA continues as the U.S. Science Team leader for the Advanced Microwave Scanning Radiometer flying on NASA’s Aqua satellite. He has provided congressional testimony several times on the subject of global warming.

      Dr. Spencer’s research has been entirely supported by U.S. government agencies: NASA, NOAA, and DOE. He has never been asked by any oil company to perform any kind of service. Not even Exxon-Mobil.

      Dr. Spencer’s first popular book on global warming, Climate Confusion (Encounter Books), is now available at Amazon.com and BarnesAndNoble.com.”

      AND Judith Curry – CVS – http://curry.eas.gatech.edu/currycv.html which is more than impressive.

      Like

    9. BAF,

      Your comment does not reassure me that you know much about climate science. When combined with your other comments it suggest you are better off sticking with the websites of NOAA, the IPCC, and Met office until you become more familiar with these things. I’ll mention one sentence.

      “The UN’s IPCC has been wrong several times and uses a lot of vague language in their reports some might call disclaimers if things aren’t what they say they are.”

      Some of that is bizarrely false. Some is delusional.

      (1) Few, if any, reports on this scale are as careful to be specific — down to explicit statements of uncertainty for its conclusions.

      (2) It as about the frontiers of knowledge. Most of it is mind-bendingly specific in the conclusions and discussions. Where things are unclear, they state what’s known or suspected to best extent possible.

      (3) It’s either mad or ignorant to consider significant that the IPCC “has been wrong several times.” Each AR is thousands of pages long. You must read mostly science reports from Heaven if you have higher standards.

      Like

    10. @BA: (assuming you were addressing me as SF Chronicle): I doubt any likely climate change is likely to end all life on Earth or something absurd, although it could make things crappier and poorer and mean that our technological progress goes towards running in place rather than moving forwards.

      I feel like posing questions in that way doesn’t really accomplish much beyond maybe scoring an internet point or something. The general hypothetical of some imminent disaster requiring mass action is interesting, but I’m more concerned about the US being economically hit by trying to subsidize fossil fuels at this point.

      Like

    11. To the editor – Since you are now going to insult these great climate scientists with your “all knowingness” and insult me, I’ll be gone.

      As an aside, I’d wager my knowledge is as vast as yours, but I don’t rely on those who have been proven to fudge the stats until they say what they want them to say, but then that’s just me.

      Why do alarmists think they can use confirmation bias telling everyone they must believe the UN’s IPCC, etc in this religion of “climate change” and hope to change the views of anyone.

      If Climate Gate 1, 2, or 3 doesn’t give pause for thought then nothing will. Good science will always remain skeptical and when there can be no dissenting opinion, it’s not science – it’s political. Everyone should know that if they know anything about science at all.

      Actually, I only came onto this site to see if your site is like all the other alarmist sites – and it is. Thanks for the conversation anyway. It’s been very instructive.

      Hopefully, none of the alarmist scientists will be treated like the more skeptical scientists who have been demeaned, subjected to ridicule, lost their positions and their funding when the opinions didn’t gee-haw with the alarmists.

      Thank goodness Galileo spoke up against the consensus at that time, was called a heretic and imprisoned. It only takes one scientist to prove a consensus wrong. Remember that when ridiculing these well credentialed dedicated climate scientists.

      Have a nice day and keep the faith.

      Like

    12. BAF,

      “Since you are now going to insult these great climate scientists with your “all knowingness” and insult me, I’ll be gone.”

      Now you’re making stuff up. I was replying to what you said, not what they said. Your last comment is delusional, not related to anything I’ve said. I suggest you reply to quotes to prevent this in the future.

      Also — you have been unable give any rebuttal to my comments. Posting bios of scientists — whom I know, respect, and never mentioned in this thread — is irrelevant.

      Like

    13. Sorry just received your reply after saying I would be gone, so in reply – Read your own comments. They are totally condescending. The UN’s IPCC have not been right in their conclusions which are based on conjecture. It would be much better if you and yours would rely on empirical evidence to make your predictions.

      The more you insult others by saying we should only read and believe the UN’s IPCC you are saying – don’t read or believe those scientists you have referenced. For future reference, that is an insult to them.

      The scientists didn’t have to be named to know who you are suggesting I not rely upon. That is not showing respect for the scientists I rely on for information. They are not deniers, but don’t think the alarmists have the science right and there are a lot of us out there. More and more scientists are speaking up now. Isn’t that great? If you like and respect Roy Spencer and Judith Curry, saying we should only rely on the UN’s IPCC and NOAA doesn’t seem respectful of what they consider the truth of climate science.

      BTW – If you reply to me with another condescending remark, I’ll be back. It’s your choice.

      Like

    14. BAF,

      “The UN’s IPCC have not been right in their conclusions which are based on conjecture.’

      You are just making stuff up. For example, I know Curry’s work very well. She says nothing remotely like that. She believes the IPCC substantially overestimates the confidence of its conclusions. That’s commonplace among experts, and among people. Using the great PBL survey, I shows that most climate scientists agree.

      But your conclusion is quite bogus.

      “They are totally condescending.”

      Just the facts, maaam. This isn’t a “safe zone.” Note you have not even tried to defend your statements against my highly specific rebuttals.

      “The more you insult others by saying we should only read and believe the UN’s IPCC you are saying”

      Also, as usual, your statement is factually false. I said “you are better off sticking with the websites of NOAA, the IPCC, and Met office until you become more familiar with these things.” That’s just good sense for some people, like you, who are grossly misinformed. Small steps. With more familiarity with the basics of climate science, you can move on to other sources.

      “I’ll be back. It’s your choice.”

      Yes, it is. I’ve been patient about this, but enough is enough. I’m moderating further comments by you. If you say something well supported — not just making stuff up and whining when called on it — I’ll post it.

      Like

  2. Of all those charts I see that one goes all the way back to…1950. The others are even more recent. What conclusions could you possibly make from such a tiny sample size?

    Like

    1. Notably, the short-run model validation is only compared with the surface records which are frequently adjusted — and never down. The satellite and balloon records seem to be more consistent yet they are not included in Schmidt’s validation. Further, while the ocean heat content is a better guide, it is not being used to validate any models. Pielke is right: temperature is a construct; joules are an objective measure.

      Like

    2. bucephelus,

      1950 is used as the (somewhat arbitrary) starting point for major AGW — “It is extremely likely (95 – 100% certain) that human activities caused more than half of the observed increase in global mean surface temperature from 1951 to 2010.” (AR5)

      Zeke shows in his Carbon Brief paper that model runs go back to 1850 or 1880.

      But for model validation to meet public policy needs, I put little weight on hindcasts (aka backtesting). Models are in various ways “tuned” to the past. As Popper said, predictions are the gold standard of science. Hence the successful forecasts described here for CMIP3 are for aprox ten years. As I said, small steps.

      More useful testing would be re-running with current observations the earlier models used in the second and third Assessment reports, giving multi-decade track records. Current models are more sophisticated, but demonstrated predictive skill by earlier models would give us more confidence in them.

      Like

  3. Why not include the satellite datasets for the lower troposphere as an independent test of the models? The surface T datasets have many problems: huge coverage gaps (notably high latitudes), extrapolations, interpolations, dodgy sea surface data, UHI effects. The satellite data have their own issues but have much better coverage and have been worked on for years so should be asymptotically approaching reliability. RSS v4 shows the same thing as the new Oxford paper–the models running hot. http://www.remss.com/research/climate.html

    Like

    1. Less than 8% of US surface temperature stations are accurate to within 1 degree. What we are seeing is just statistical noise.

      Like

  4. About the comment of the overuse of scenario RCP8.5. A lot of research on climate change impacts is limited by the CORDEX datasets, which provide scenarios from regional climate models, since the global model results are too coarse to be useful in many applications. So far most of CORDEX provides results for RCP4.5 and RCP8.5 only; updates for RCP2.6 are being slowly made available, and I think updates for RCP6.0 are not foreseen.

    So I think you often get results for RCP4.5 and RCP8.5 because these are the only scenarios available; and that, even if these scenarios are correctly characterized as “most likely” and “worst case” in the methods section of a paper, most people will read the abstracts and the results and misinterpret the conclusions as some kind of lower and upper boundary. The fact that “climate change impact” and “climate change adaptation” are increasingly becoming separate research fields doesn’t help, as I believe that even adaptation researchers are misreading the impact assessments.

    It also doesn’t help that the whole IPCC AR5 scenario structure is complicated and full of acronyms such as RCPs and SSPs. For example, it is not correct to say that RCP8.5 has specific socio-economic assumptions; the IPCC has a range of socio-economic scenarios (SSP1 to 5), each of which will lead to a range of RCPs. However, it is correct to say that RCP8.5 is only reached by SSP5, loosely described as “strong economic development driven mostly by fossil fuels”. But, to confuse things, SSP5 can also lead to RCP4.5 or RCP6.0. I can understand why many researchers misunderstand this, and why it’s difficult to explain it to a broader audience. Here’s an attempt at a simple explanation: https://climate4impact.eu/impactportal/documentation/backgroundandtopics.jsp?q=Scenarios

    JP

    Like

    1. JCP,

      “even if these scenarios are correctly characterized as “most likely” and “worst case” in the methods section of a paper, most people will read the abstracts ”

      I have read read the full papers of the those I cite, and very few until recently followed the practice you describe. See the cites (with links) and quotes of the specific language use in this post.

      “So I think you often get results for RCP4.5 and RCP8.5 b”

      Until the past year, RCP4.5 was cited far less often than RCP8.5 — and then with RCP8.5. I never saw RCP4.5 without RCP8.5.

      “which provide scenarios from regional climate models”

      Most papers deal with global results. Appropriately so, since downscaled models (either vertically in the atmosphere or geographically) have not been shown to demonstrate much predictive skill. They make for dramatic reading, however.

      “It also doesn’t help that the whole IPCC AR5 scenario structure is complicated and full of acronyms such as RCPs and SSPs.”

      That’s not remotely a problem for the audience — which is scientists. The IPCC Summary for Policy Makers in their AR are written quite clearly. And science journalists should be able to clearly explain this. They certainly have no trouble mis-representing the studies.

      “loosely described as “strong economic development driven mostly by fossil fuels”. ”

      Buy “loosely” you should say “incorrectly.” It assume large changes in long-standing trends — such a technological stagnation and a stop to the two centuries of fertility decline (that’s how they get the rapid population growth).

      “I can understand why many researchers misunderstand this,”

      The papers describing the assumptions which create the RCPs are clearly stated and not very complex. The underlying mechanics are complex, but the trends in the pathways that get us there are not.

      Like

  5. Thanks again for keeping facts on the table re the climate debate. We’re still woefully short on preparing for the predictable impacts of even the lower end warming scenarios. You’re insight that we are no prepared for the past tells a lot about the current state of public debate in America.

    During Harvey I heard an interview with the Lieutenant Governor of Louisiana calling for restoration of the barrier islands and wetlands to provide hurricane protection as if that need was news. I recall several great analyses showing both the need and the economic payoff of such efforts came out following Katrina, but apparently not much has happened. Presumably the same will occur following this year’s hurricanes.

    One question for the group. There was a good bit of discussion with Irma that a factor in maintaining the strength of the storm was abnormally high OHC at depth, which prevented deep water upwelling from ameliorating storm energy. Does anyone have insight on the reality of those claims and, if so, on whether continued OHC warming will have a longer term impact on future storm strength?

    Like

    1. John,

      I suggest you post that at a website discussing climate science at a technical level. The subject here is the public policy debate about climate change. Climate science is, of course, a major input to that. But detailed discussion of that is beyond my paygrade. NOAA’s website blog post about this, and would be an ideal place to get a good answer.

      Like

  6. My first thoughts, when seeing so much hoopla being made over a successful 10-year forecast by a model, are:

    1) wait, aren’t climate cycles typically reckoned as being about 30 years? This seems just too short a period to be significant;

    2) one model was successful? Well, that’s just super, but, given models typically “running hot”, such excitement about one successful projection smacks a little of the Texas sharpshooter fallacy.

    Like

    1. a devil,

      “This seems just too short a period to be significant;”

      Did you read the post? I explain that in detail. This is a start. The longest journey begins with the first step.

      “one model was successful?”

      CMIP is the primary modeling complex. Hence its success is milestone.

      Like

    2. It doesn’t matter that you explain in detail. A small sample size is a problem that can’t be overcome. We just don’t have enough data. The records we have start in the late 1800s just as the Little Ice Age was ending.

      Like

    3. bucephelus,

      Your comment makes zero sense. I said it was a start. I didn’t say it was an end or conclusive or whatever it is you’re imagining.

      “A small sample size is a problem that can’t be overcome.”

      This just in: there are statistical tools to determine validity of probabilities. Forecasts of 20+ years become statistically significant.

      Like

    4. Not sure why it makes zero sense. With a small sample size your error margin is +-100%. It works that way in climate science, polling, medical studies, etc….There’s no way around it. 20 years is ridiculously small for a climate trend analysis.

      Like

    5. You know, every time I begin to develop a modicum of respect for your site, for the odd actually insightful, worthwhile article you post, you go and completely destroy it by answering criticism in the most infantile, petulant manner imaginable. If you want to be taken seriously, I’d suggest you stop acting like a twelve-year-old on Twitter, every time someone points out the glaring flaws in your arguments.

      I might remind you of your own words, by the way: “I even more strongly recommend against putting to much weight on one paper. This is called ‘single-study syndrome’.”

      This is my point, in a nutshell.

      Like

    6. adevil,

      ” answering criticism in the most infantile, petulant manner imaginable”

      I see facts make you uncomfortable, and you react emotionally. That’s a common problem in our time, with people both Left and Right living in an info bubble — unexposed to other perspectives. Perhaps you would be happier in a “safe space” where you will only see views congenial to you. That’s not here.

      This discomfort is easily visible when people are exposed to freshman level material — such as “science advances in in increments” and don’t understand it, and cannot reply. Scientists on both sides — Roger Pielke Sr. and Gavin Schmidt — both liked this on Twitter, since it’s pretty obvious.

      “every time someone points out the glaring flaws in your arguments.”

      You haven’t done so. Just misstating what I said, plus whining. I recommend replying to direct quotes, so there will be some correspondence between what I say and your rebuttal.

      “This is called ‘single-study syndrome’”

      This isn’t a paper. It is a widely remarked match of data with forecasts. Many scientists have written about this. The observation-forecast gap has been closing for 2 years, and has gotten a great deal of attention. It’s not problematic or debated — among scientists, but lots of screams from deniers (e.g., literal deniers, not skeptics).

      Like

    7. Well, you’re determined to double down on your childish petulance, I’ll give you that. But persistence is scarcely a virtue, in this case.

      The cavalcade of nonsense in your last reply – from childish attacks, to misleadingly quoting what were in fact your words as if they were my own – really stands as its own testament, but perhaps the most precious one is boasting of who liked you on Twitter. Good Lord, did you actually mean to write that?

      Like

  7. The IPCC already admitted that it is currently impossible to forecast figure climate beyond a probability.

    Adding CO2 MAY make a warmer climate in future. But there is still a chance it won’t. Such is the nature of probability on forecasts.

    Like

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