This is one of those times I’m really glad WiFi has been installed on passenger aircraft. After reviewing this paper at Nic Lewis’ home prior to that extraordinary meeting with climate scientists I mentioned, and expecting a leisurely writeup in about a week, Nic sends me this email which I get on the plane:
Anthony, Climate Dynamics has released my paper nearly a week earlier than they said!!
This is a significant paper. As I once read on Climate Audit:
This will set the cat amongst the pigeons
Here is the paper at Climate Dynamics: http://link.springer.com/article/10.1007/s00382-014-2342-y
The implications for climate sensitivity of AR5 forcing and heat uptake estimates
Abstract
Energy budget estimates of equilibrium climate sensitivity (ECS) and transient climate response (TCR) are derived using the comprehensive 1750–2011 time series and the uncertainty ranges for forcing components provided in the Intergovernmental Panel on Climate Change Fifth Assessment Working Group I Report, along with its estimates of heat accumulation in the climate system. The resulting estimates are less dependent on global climate models and allow more realistically for forcing uncertainties than similar estimates based on forcings diagnosed from simulations by such models. Base and final periods are selected that have well matched volcanic activity and influence from internal variability. Using 1859–1882 for the base period and 1995–2011 for the final period, thus avoiding major volcanic activity, median estimates are derived for ECS of 1.64 K and for TCR of 1.33 K. ECS 17–83 and 5–95 % uncertainty ranges are 1.25–2.45 and 1.05–4.05 K; the corresponding TCR ranges are 1.05–1.80 and 0.90–2.50 K. Results using alternative well-matched base and final periods provide similar best estimates but give wider uncertainty ranges, principally reflecting smaller changes in average forcing. Uncertainty in aerosol forcing is the dominant contribution to the ECS and TCR uncertainty ranges.
A PDF file of a reformatted version of the final revised manuscript titled ‘The implications for climate sensitivity of AR5 forcing and heat uptake estimates’, with minor editing corrections, is available here: Lewis&Curry_AR5 energy budget climate sensitivity_Clim Dyn2014_accepted (reformatted, edited). This work was accepted for publication by Climate Dynamics on 13 September 2014.
A compressed zip file containing data and computer code that will generate the results in the paper is available here: AR5-EB-LewisCurry-ClimDyn-2342
Nic is preparing a discussion about the paper to post at Climate Audit, I’ll add it when it is ready – Anthony (somewhere over Canada)
UPDATE: The CA post is up at http://climateaudit.org/2014/09/24/the-implications-for-climate-sensitivity-of-ar5-forcing-and-heat-uptake-estimates-2/
EXCERPT:
When the Lewis & Crok report “A Sensitive Matter” about climate sensitivity in the IPCC Fifth Assessment Working Group 1 report (AR5) was published by the GWPF in March, various people criticised it for not being peer-reviewed. But peer review is for research papers, not for lengthy, wide-ranging review reports. The Lewis & Crok report placed considerable weight on energy budget sensitivity estimates based on the carefully considered AR5 forcing and heat uptake data, but those had been published too recently for any peer reviewed sensitivity estimates based on them to exist.
I am very pleased to say that the position has now changed. Lewis N and Curry J A: The implications for climate sensitivity of AR5 forcing and heat uptake estimates, Climate Dynamics (2014), has just been published, here. A non-paywalled version of the paper is available here, along with data and code. The paper’s results show the best (median) estimates and ‘likely’ (17–83% probability) ranges for equilibrium/effective climate sensitivity (ECS) and transient climate response (TCR) given in the Lewis & Crok report to have been slightly on the high side.
Our paper derives ECS and TCR estimates using the AR5 forcing and heat uptake estimates and uncertainty ranges. The analysis uses a global energy budget model that links ECS and TCR to changes in global mean surface temperature (GMST), radiative forcing and the rate of ocean etc. heat uptake between a base and a final period. The resulting estimates are less dependent on global climate models and allow more realistically for forcing uncertainties than similar estimates, such as those from the Otto et al (2013) paper.
Base and final periods were selected that have well matched volcanic activity and influence from internal variability, and reasonable agreement between ocean heat content datasets. The preferred pairing is 1859–1882 with 1995–2011, the longest early and late periods free of significant volcanic activity, which provide the largest change in forcing and hence the narrowest uncertainty ranges.
Table 1 gives the ECS and TCR estimates for the four base period – final period combinations used.
Table 1: Best estimates are medians (50% probability points). Ranges are to the nearest 0.05°C
AR5 does not give a 95% bound for ECS, but its 90% bound of 6°C is double that of 3.0°C for our study, based on the preferred 1859–1882 and 1995–2011 periods.
Considerable care was taken to allow for all relevant uncertainties. One reviewer applauded “the very thorough analysis that has been done and the attempt at clearly and carefully accounting for uncertainties”, whilst another commented that the paper provides “a state of the art update of the energy balance estimates including a comprehensive treatment of the AR5 data and assessments”.
Full report here: http://climateaudit.org/2014/09/24/the-implications-for-climate-sensitivity-of-ar5-forcing-and-heat-uptake-estimates-2/
UPDATE2: Judith Curry weighs in. More details on the paper at
http://judithcurry.com/2014/09/24/lewis-and-curry-climate-sensitivity-uncertainty/
Among “Climate Scientists” Richard Lindzen and Judith Curry stand out.
Richard has the “Gravitas” to address august bodies such as the British “House of Parliament”.
Judith Curry engages with the general public better than anyone. Not even the redoubtable Anthony Watts can match the volume of comments that Judith’s posts attract.
That said I am disappointed that Richard and Judith imagine that there is some validity to the 1896 hypothesis by Svante Arrhenius that says:
“The selective absorption of the atmosphere is……………..not exerted by the chief mass of the air, but in a high degree by aqueous vapor and carbonic acid, which are present in the air in small quantities.”
The Arrhenius hypothesis is nonsense but it lingers on because the CO2 concentration in the atmosphere has correlated with global temperatures over the last 800,000 years.
Thanks to ice cores we have a precise record of temperature and [CO2]. These records show that the correlation is a consequence of Henry’s law rather than the Arrhenius hypothesis:
http://diggingintheclay.wordpress.com/2013/05/04/the-dog-that-did-not-bark/
Arrhenius was first refuted by Wood (1909), whose experiments/results are easily repeatable. Unlike Arrhenius and those who follow in his footsteps who can’t be bothered to do actual experiments or stuff like that. Here’s a thorough discussion:
http://greenhouse.geologist-1011.net/
Arrhenius has been refuted so completely, it’s really a joke that his “Greenhouse Effect” is taken seriously by climate ‘scientists’. Obviously, these guys have never had a real greenhouse so don’t have a clue how it actually does what it does.
Thanks for that! So any scientist should know that CO2 is not the dominant driver of climate that Arrhenius claimed.
So why are governments around the world trying to reduce CO2 emissions when they should know it will have no detectable effect on global temperature?
gallopingcamel September 25, 2014 at 6:43 pm
They should. And I find it hard to believe that any of them don’t know it. Therefore:
The perpetrators of CAGW never intended to do science. And they have not. They simply provided a plausible cover story for a political agenda, then shouted down, intimidated and silenced anyone who objected. The agenda isn’t about global temperatures or saving Gaia or the polar bears. It’s not even about CO2. It’s about control and power. The same pig, new lipstick.
I too believe, as others have aluded to, that ECS and TCR are not only a function of the doubling of CO2 but also a function of ([H2Osolid],[H2O liquid],[H2Ogas]) in the atmosphere. Unfortunately these concentration vary so widely over short, medium and long terms and spatially across the planet that an “average” of these values over a 70 year period would be meaningless. The strongest function affecting the local influence of CO2 is how much water(liquid) is present in the atmosphere. There is no way that these calculated numbers can be constants! Why? Because CO2 is scrubbed from the atmosphere by liquid water. Because warming up liquid water in the oceans raises the local CO2 concentration. Because, in the presence of high humidity, CO2 plays practically no role whatsoever in the green house effect. Because on any given day, or during any given month, or even over several years the cloudiness of any given location (or the snowiness) drastically affects the reflection of heat back into space regardless of the local CO2 concentration. And because in the few locations on planet earth where [H2O] is low enough for CO2 to actually have a green house effect, the local temperature swings widely from mid-day to darkest night! Face it, measuring CO2 at one spot on the planet where there is minimal influence of water vapor and then believing that your measured value can somehow CAUSE a fixed effect on the overall temperature of the planet is simply too naive – IMHO. CO2 is denser than water vapor. Water vapor can get higher into the atmosphere at higher concentrations and can condense and fall back to earth carrying CO2 with it. To try to get an estimate of these two “constants” by comparing a perceived period when the inflence of CO2 should have been “low” and when it should be “high” assumes of course that the [CO2] in the atmosphere was accurately measured during these two time periods – the world over! So call me skeptical. To show any single variable affect of a doubling of CO2 where CO2 is actually CAUSING the effect, and not be effected by the actual cause, you will need to show me similar calculated results from more than just two 70 year periods where the numbers actually agree with each other. More importantly, the cause -> effect needs to be demonstrably CONSISTENT. . . . ie. where one variable [CO2] is consistently rising, the other should also be consistently rising!!! At the very least someone should perfom these same three calculations at three distinct time periods that are separated along the curve where there is a measureable difference of CO2 and where the temperature was also measured AT THAT SAME SITE. In my humble opinion, even though the use of their own data showed just how improbable IPECACs predictions are, this paper still uses their data – “garbage in”. . . . . and we all know of course GI=GO.
PG,
As you are a Climate Activist lawyer, it is likely you are more attuned to the PR side of Climate Change than to the science-side anyway.
So I ask “what happens to Obama and his Climate Change dogma when the US goes through a brutal winter(or two)?” When temperatures winter temps plummet worse than last winter, and the GL’s freeze over even earlier? When people are freezing in their homes because his oil, gas, and electricity brought on by bad Obama energy policies?
Obama is an ideologue. He doesn’t recognize other opinions when his mind is set. But he does understand the politics of public opinion. Will he be forced to change his mind (like he had to on bombing Syria)? If you had asked Joe Biden or Obama 2 years ago what they thought the odds of them ordering US bombing (especially non government rebels) inside Syria, they’d have said “zero chance”. Biden was admamant that we were done with combat ops in Iraq.
Things change. and so will this fever called “climate Change.” Where will Climate Activist lawyers be then? In the bread-lines with the McKibben-ites, I hope.
Sorry I just can’t get my head around all this climate sensitivity stuff when my city of Adelaide shows this kind of min/max temperature forecast for various suburbs of the greater metro area-
Adelaide 9 21
Elizabeth 7 21
Glenelg 9 19
Noarlunga 11 20
Mt Barker 7 20
C’mon Big Climate modellers and BOM cheer squads. Surely if you can homogenise and mangle thermometers hundreds of kilometres apart you can manipulate one small city lot better than that?
http://www.bom.gov.au/sa/forecasts/adelaide.shtml
Most likely TCR = 1.33 C. The world has already warmed by at least 1 C since 1750. So expect 0.33 C warming when CO2 reached 560 ppm. Is that catastrophic? Unless the global warming since 1750 is not due to CO2. If so, it’s all natural climate change.
Is it Nicholas Stern AGW, warmist extraordinaire, the cause of such unwarranted hilarity?
It would have helped if we had had a thermometer in the middle of the Sahara, the Gobi, and Death Valley and recorded the nighttime temperature over the past 100 or so years.
Anyway, to include the natural variation part the period should cover enough time for an even number of hot/cold PDO/AMO regimes. In the last century we seem to have had two where el nino dominated and only one where la nina did. We’re in the 4th cooling period now-except we’re not cooling (yet, anyway).
But, whatever, we’ll continually refine the figures hopefully. And people will pay attention. Not so hopefully.
What I like about the paper is that Lewis and Curry have chosen different periods to compare …
… including 2 periods which are probably the very best to use in that volcanoes and the AMO cycles would not be expected to have a substantive impact on the results (1859-1882 versus 2005-2011).
The pro-AGW climate scientists are unlikely to have published the data using these two periods although they might have calculated it. But when they saw the results of this calculation, they would have just moved on to two other periods where cherrypicking would produce high numbers. But then, this is what they do
As important as this paper is, I want to take Nic and Judith to task a bit for not emphasizing how AR5, and by extension their own analysis, ignores the uncertainty in solar forcing. As I commented above, they do note that they are ignoring possible forcing effects from UV shift and any other mechanism of “solar amplification” (solar effects other than changes in total electromagnetic radiation, or TSI), but then in their discussion of remaining uncertainties they omit mention of this omitted variable.
This pattern appears both at the end of their abstract:
And at the end of their conclusion:
Aerosol forcing might be the most important uncertainty amongst the included uncertainties, and there are unknown unknowns that the authors cannot be faulted for omitting, but there is a huge known unknown — the magnitude of non-TSI solar forcing effects, that MUST be mentioned. As it stands, the paper’s summary conclusion about the sources of remaining uncertainty is just wrong.
I seem to recollect that in at least one his earlier climate sensitivity posts here at WUWT Nic Lewis was careful to note that any increase in the amount of 20th century warming that can be attributed to high solar activity would decrease the warming that can be attributed to CO2, which would decrease the implied climate sensitivity. Did this important proviso get jettisoned by the peer review process? If so, I think the details of that should be made public.
An entirely different approach described at http://agwunveiled.blogspot.com has a 95% correlation and determines climate sensitivity of zero.
The Lewis and Curry research is well done and provides encouraging results. But one question: given that the work is predicated on global conservation of energy, what is the uncertainty of the findings that results from the uncertainty in the global energy balance?
My question is prompted by my experience and the results of a fairly sophisticated energy balance measurement for a sizeable industrial melting furnace that showed an ~3% discrepancy between input and output energy. For me, intuitively, this suggests that the global energy balance is likely not very well known or accurate.
If this uncertainty was covered in the paper, and I missed it, please point me to the appropriate section of the paper.
Thanks
Dan
A quick run of the MODTRAN calculator shows us doubling CO2 shows a 2.78 Centigrade rise. What the calculation ignores is night time. So halve it and what do we get… 1.39 Centigrade.. Am I close enough when we consider the height of the stratosphere which gives a shorter night, will up that number around an eighth to ~1.6 Centigrade per doubling? 😉
Where’s the evidence that CO2 has ever caused warming?
Why has there been no warming for the past decade?
All evidence suggests CO2 changes are a result of temperature changes, NOT a cause.