Bishop Hill Dialing back the alarm
Sep 14, 2013 Climate: Surface Climate: sensitivity Matt Ridley has an article in the Wall St Journal today, looking at how the forthcoming Fifth Assessment Report is handling climate sensitivity and the halt in temperature rise. Most of this will be familiar stuff to BH readers. Here's how he concludes:
Since the last IPCC report in 2007, much has changed. It is now more than 15 years since global average temperature rose significantly. Indeed, the IPCC chairman Rajendra Pachauri has conceded that the "pause" already may have lasted for 17 years, depending on which data set you look at. A recent study in Nature Climate Change by Francis Zwiers and colleagues of the University of Victoria, British Columbia, found that models have overestimated warming by 100% over the past 20 years.
Explaining this failure is now a cottage industry in climate science. At first, it was hoped that an underestimate of sulfate pollution from industry (which can cool the air by reflecting heat back into space) might explain the pause, but the science has gone the other way—reducing its estimate of sulfate cooling. Now a favorite explanation is that the heat is hiding in the deep ocean. Yet the data to support this thesis come from ocean buoys and deal in hundredths of a degree of temperature change, with a measurement error far larger than that. Moreover, ocean heat uptake has been slowing over the past eight years.
The most plausible explanation of the pause is simply that climate sensitivity was overestimated in the models because of faulty assumptions about net amplification through water-vapor feedback. This will be a topic of heated debate at the political session to rewrite the report in Stockholm, starting on Sept. 23, at which issues other than the actual science of climate change will be at stake.
Reader Comments (12)
The deep ocean heat storage idea is a load of cobblers, but nonetheless it didn't stop it being cited. What irks me the most is that models/predictions/guesses are being touted as 'science' that is sufficiently robust enough to base policy decisions on it. As the extent of the overstatement of CO2 sensitivity of the climate becomes apparent, surely the political classes will realise the game is up. Fool them once shame on you, fool them twice shame on them....
The current plateau of average temperature implies that CO2 is not the "Control Knob" of Earth's temperature as has been stated by several climatologists. CO2 seems analogous to gasoline in a car: the amount of gasoline presented to the cylinders of a car correlates with the RPMs of the engine, but not necessarily with the speed of the vehicle. Other systems, such as gear ratio and brakes can alter car speed thus removing the correlation between gasoline and speed. The climatologists have oversimplified control of Earth's temperature and have exaggerated the importance of CO2 in temperature control.
Morley Sutter
Nice analogy, send it to your MP.
Otherwise, it could be that climate science has a woefully inadequate understanding of the processes involved in the climate. That's before we even get to models.
I will be most surprised if the IPCC is prepared to consider that its assumption that positive water vapour feedback might be at fault. Surely the repercussions at international government level would be too serious to contemplate. In fact it would lead to either the abolition of the Panel, or at least a complete change in its charter. No, my money is on a complicated, arm waving fudge. One that will pacify the politicians, though not answer the science.
AR5.
IPCC to governments: "Please continue funding us despite our consistent track-record of AR1, AR2, AR3 & AR4 not correlating with reality."
Does anyone have inside knowledge of what is going on with AR5 and the International Govts?
Are the Govts saying, "You need to sex this up, otherwise the gravy train will end and our citizens are going to lynch us."
OR...
Is the IPCC saying, "No really, please don't listen to anyone else. It's still as bad or worse than we previously told you."
Criminal incompetence all around, including Morley Sutter's comment above--CO2 as the fuel powering the car (lucky it's only 0.04% of the air then; but then, it's 96.5% of Venus's air, and yet has no more effect there than here, as I and I alone precisely showed nearly 3 years ago, to universal silence among the alarmists and lukewarmers alike). And Ridley's "most plausible explanation" for the temperature pause--knowledge of the "feedbacks" a little off. How about past "pauses" (actually, declines in temperature, in the records)--1880 to 1910, and 1940 to 1975? Even the academics divided the first and second half of the 20th century, with solar considered the "control knob" of temperature in the former, and CO2 in the latter. Yet the correlation of CO2 with temperature was always and ever only from 1976 to around 2000--and that is the real explanation, that climate scientists matched CO2 with temperature in that 25 year period, and that period alone, and built their models on "saving the appearance" that that period was representative, when it obviously was not, given what everyone already knew about the ups and downs in temperature over the last century and a half. It didn't take expert statisticians to see that, it should have been quickly obvious to any competent physical scientists--of which there literally are none among the ranks of alarmists and lukewarmers, Bishop Hill included. So long as you make the debate between those saying "the science is settled" and those saying "the science is just a little off", you are living a lie.
I don't always agree with Harry (don't understand half of it; my fault, not his) but there doesn't seem any doubt that the CO2/temperature correlation is not all that great over the long-term and my gut feeling has always been that you can't take a trace gas at a concentration of <400 ppm and suddenly decide that it's a major driver of temperature when there is no evidence that it has been before.
Unless you have something personal against the stuff. Or against what mainly produces it.
Which brings us back neatly to the eco-activists and their pathological hatred of civilisation and therefore the hydrocarbons that have underpinned it.
"The most plausible explanation of the pause is simply that climate sensitivity was overestimated in the models"
LOL, the models rule the earth.
Harry Dale Huffman:
You seem to have misread my comment at 12:45 PM: gasoline, not CO2 powers most cars, including the one in my analogy.
Morley sutter
@Harry Dale Huffman
Whatever ones position on Greenhouse Gases, and it is 50 years since I first sat in a lecture theatre and met the theory, it is the case that the IPCC was originally tasked with researching the GHG effect, proving the theory and putting a value to it.
As far as I can see that was never done and as such the GHG theory remains just that.