Memo to media, deniers: “Climate sensitivity” is NOT the same as projected future warming!
Projected warming even with (an unlikely) low climate sensitivity of between 1.5°C and 2.0°C from Michael Schlesinger et al 2012. A WSJ op-ed that cites this work absurdly concludes “Evidence points to a further rise of just 1°C by 2100.” Not even close — one of the key math errors in the piece.
Every major projection of future warming makes clear that if we keep listening to the falsehoods of the anti-science crowd and keep taking no serious action to reduce carbon pollution we face catastrophic 9°F to 11°F [5°C to 6°C] warming over most of the U.S. (see literature review here).
The Wall Street Journal, however, has published a piece, “Cooling Down the Fears of Climate Change,” that (falsely) asserts observations suggest global warming will be so low as to “be benificial.” This risible piece by Matt Ridley is so riddled with basic math and science errors it raises the question of how the Journal can possibly maintain its reputation as a credible source of news and financial analysis.
Ridley and the Journal apparently don’t know the difference between water vapor and clouds. They don’t understand the basic concept of climate sensitivity. And they can’t do simple math. Naturally, the climate deniers have embraced this nonsense and spread it across the internet.
UPDATE: Ridley has made an even more self-defaming response at Bishop Hill’s blog and WattsUpWithDisinformation. He doesn’t actually refute any of my points — just repeats his mistakes. His piece proves once and for all that Ridley doesn’t know the first thing about climate science or the IPCC. As but the most astounding example, in my debunking below I explicitly quote the IPCC’s draft Fifth Assessment (AR5) — “the new IPCC draft report, upon which Ridley makes all his claims” — which summarizes the recent literature on clouds this way: “The net radiative feedback due to all cloud types is likely positive.” Ridley then absurdly asserts “He gives no backing for this dogmatic conclusion.” Seriously. It’s like he never read my piece — or the AR5! And he apparently thinks you can’t read either! I must say it is shocking that Bishop Hill would print such an easily falsifiable claim. It is not shocking Watts would.
I wasn’t going to waste time with the umpteenth debunking of the Wall Street Journal’s nonsense — especially a piece written by someone whose “family leases land for coal mining”! But one of Ridley’s many basic mistakes is often seen in the media — the confusion of the “climate sensitivity” (to a doubling of CO2 levels to 560 parts per million) with projected warming (from actual greenhouse gas levels projected for this century plus carbon cycle feedbacks). That confusion needs clearing up (again).
First, though, let me start by quoting some of the country’s leading climate experts in an excellent debunking piece by Media Matters, “WSJ’s Climate ‘Dynamite’ Is A Dud”:
[A]s John Abraham, an IPCC reviewer and the director of the Climate Science Rapid Response Team, put it to Media Matters: the column “has such elementary errors in it that [it] casts doubt on the author’s understanding of any aspects of climate change.”
I know of no evidence that would suggest that the temperature effect of sulfur emissions are small. This conclusion is totally at odds with my peer reviewed publication in the area, which indicate that sulfur emissions have a significant effect on temperature.
With regard to the feedback effect of water vapor: Kevin Trenberth, a scientist with the National Center for Atmospheric Research, told Media Matters in an email: “water vapor effects are well established as an amplifier (strong positive feedback).” Abraham further noted that Ridley has apparently confused water vapor with clouds, whose effects are not as well understood. He said, “it is very clear water vapor … is an amplifying effect. It is a very strong warmer for the climate” and challenged Ridley to name the anonymous scientist who gave him his information.
With regard to the rate of ocean heat absorption: Trenberth wrote: “On the contrary there is now very good evidence that a LOT of heat is going into the deep ocean in unprecedented ways, which completely undermines this sort of argument. OHC [Ocean Heat Content] keeps increasing at a fairly steady rate, just as sea level keeps going up.”
A good discussion of the latest science on ocean heat content can be found here.
To expand on what Abraham said, it is head-exploding and self-discrediting for Ridley and the Wall Street Journal to print this for millions to read:
And then, as one Nobel Prize-winning physicist with a senior role in combating climate change admitted to me the other day: “We don’t even know the sign” of water vapor’s effect — in other words, whether it speeds up or slows down a warming of the atmosphere.
Climate models are known to poorly simulate clouds, and given clouds’ very strong effect on the climate system — some types cooling the Earth either by shading it or by transporting heat up and cold down in thunderstorms, and others warming the Earth by blocking outgoing radiation — it remains highly plausible that there is no net positive feedback from water vapor.
An unnamed physicist? Seriously, WSJ? What’s next. “A guy I met in an underground parking lot”?
If Ridley did in fact talk to a Nobel prize-winning physicist then that person almost certainly did not make the mistake Ridley did and confuse “water vapor’s effect” — where we most certainly know the sign (it speeds up warming) — with cloud’s effect (where there is a tad more uncertainty). Yet even in that case, the new IPCC draft report, upon which Ridley makes all his claims finds:
Various feedbacks associated with water vapour can now be quantified, and together they are assessed to be very likely positive and therefore to amplify climate changes. The net radiative feedback due to all cloud types is likely positive.
UPDATE: Ridley wrote this transparent falsehood at Bishop Hill’s blog:
And this guy is a taken seriously by anyone? The “backing” — the draft AR5 — is here.Memo to Ridley: You ought to actually read the assessments (and blog posts) you quote from! In case you didn’t know, the AR4 “consensus” was based primarily on the literature from before 2006. More recent science finds that the cloud feedback is positive:
- Journal of Climate (11/2010): New cloud feedback results “provide support for the high end of current estimates of global climate sensitivity”
- Science (7/2009): “Clouds Appear to Be Big, Bad Player in Global Warming” — an amplifying feedback (sorry Lindzen and fellow deniers)
Ridley and the WSJ cite on their behalf recent work by Ring and Schlesinger to help make the case that we face a warming of only another 1°C this century for a total cumulative warning of under 2°C:
Michael Ring and Michael Schlesinger of the University of Illinois, using the most trustworthy temperature record, also estimate 1.6°C [climate sensitivity].
The problem is that Ridley apparently doesn’t have the first clue what the climate sensitivity means, which is a key reason why Dr. Schlesinger has written a letter to the WSJ (below) explaining
“In his article, Mr. Ridley is just plain wrong about future global warming.”
It bears repeating that the amount of warming we are going to subject our children and countless future generations to depends primarily on three factors:
- The so-called “equilibrium climate sensitivity” — the sensitivity of the climate to fast feedbacks like sea ice and water vapor — or how much warming you get if we only double CO2 emissions to 560 ppm and there are no major “slow” feedbacks. We know the fast feedbacks, like water vapor, are strong by themselves (see Study: Water-vapor feedback is “strong and positive,” so we face “warming of several degrees Celsius” and Skeptical Science piece here).
- The real-world slower (decade-scale) feedbacks, such as tundra melt (see “Carbon Feedback From Thawing Permafrost Will Likely Add 0.4°F — 1.5°F To Total Global Warming By 2100”.
- The actual CO2 concentration level we are likely to hit, which is far beyond 550 ppm (see U.S. media largely ignores latest warning from climate scientists: “Recent observations confirm … the worst-case IPCC scenario trajectories are being realised” — 1000 ppm).
Given that the anti-science, pro-pollution forces seem to be succeeding in their fight to keep us on our current emissions path, it’s no surprise that multiple recent analyses conclude that we face a temperature rise that is far, far beyond dangerous (see links below).
Schlesinger’s full letter to the WSJ is:
In “Cooling Down the Fears of Climate Change” (WJS, 19 December 2012), Matt Ridley mentions the findings of my Climate Research Group’s paper “Causes of the Warming Observed Since the 19th Century” (http://www.scirp.org/journal/PaperInformation.aspx?paperID=24283).
In his article, Mr. Ridley is just plain wrong about future global warming.
In our paper “A Fair Plan to Safeguard Earth’s Climate” (http://www.scirp.org/journal/PaperInformation.aspx?paperID=20038), we show that by the middle of this century the warming will exceed the 2°C (3.6°F) maximum allowed by the UN Framework Convention on Climate Change to “prevent dangerous anthropogenic interference with the climate system”.
In that paper and its sequel, “A Revised Fair Plan to Safeguard Earth’s Climate” (http://www.scirp.org/journal/PaperInformation.aspx?paperID=23864), we phase out the emission of greenhouse gases this century such that the cumulative greenhouse-gas emissions by the Developing and Developed Countries are equal. Both Plans keep global warming below the UNFCCC allowable maximum of 2°C.
Schlesinger sent an email around to some journalists and scientists that included a figure from his work, which I posted at the top. Schlesinger notes that an aggressive program of carbon mitigation can limit warming to 2°C and avoid the worst impacts.
It is worth pointing out that there is a healthy debate about Schlesinger’s low estimate (see here). Kevin Trenberth, for one, says the analysis is not correct.
Indeed, Trenberth coauthored a major new study of actual observations of relative humidity finds “that warming is likely to be on the high side of current projections … projecting a global temperature rise for doubled carbon dioxide of more than 7 degrees F” — see “Science Stunner: Observations Support Predictions Of Extreme Warming And Worse Droughts This Century.”
And Schlesinger himself says it would be unwise to plan on a low sensitivity given the very real risks that it is not so low. I queried Schlesinger about whether his analysis included the feedback from the permafrost. He wrote me back:
What will most likely happen is … permanent outgassing of carbon dioxide from permafrost and methane from clathrates/hydrates. As you know, methane is a greenhouse gas that is 23 times more potent, molecule for molecule, than carbon dioxide. If we hedge not against this outgassing, it’s game over.
My Climate Research Group is now writing a paper about sea-level rise throughout this century.
You and the world want not to know about this.
In the scheme of things, we human beings are not a very intelligent species.
All species have a finite lifetime.
Most species do not self exterminate.While this is a bit hyperbolic, it may not be far from the truth.
So I think it is quite safe to say that it is irresponsible and indefensible to quote Schlesinger’s work in an article that nonsensically concludes the “net effect [of global warming] on the planet may actually be beneficial.”
Ironically — or, rather, tragically — if the world listens to anti-science disinformation like Ridley’s piece in the WSJ, if it continues taking little action to reduce carbon pollution, then that would guarantee catastrophic impacts even in the unlikely event the equilibrium climate sensitivity is low.
- Hadley Center: “Catastrophic” 5–7°C warming by 2100 on current emissions path
- M.I.T. doubles its 2095 warming projection to 10°F — with 866 ppm and Arctic warming of 20°F
- Our hellish future: Definitive NOAA-led report on U.S. climate impacts warns of scorching 9 to 11°F warming over most of inland U.S. by 2090 with Kansas above 90°F some 120 days a year — and that isn’t the worst case, it’s business as usual!“
- Climate Sensitivity Higher Than We Thought, Researchers Find
- Yes, Deniers And Confusionists, The IEA And Others Warn Of Some 11°F Warming by 2100 If We Keep Listening To You
- “The Copenhagen Diagnosis” warns “Without significant mitigation, the report says global mean warming could reach as high as 7 degrees Celsius by 2100.”