Climate model sensitivity

Glad I am to report that at least one influential non-skeptic thinks that the accepted climate sensitvity to CO2 is very overblown. Skeptical in this case largely refers to Richard Lindzen, Roy Spencer, and other climatologists who think the IPCC is overly alarmist in it's projections. Oddly non-skeptical conventionally means that you accept the IPCC report. But a little known fact is that you can accept the IPCC report but prefer the lower projected increase in temperature of 1.1K per doubling of CO2. Yes that is allowed - it's called being a lukewarmer. And in that case to be skeptical is to reject the alarmism that appears only in the newspapers but not in the IPCC documents. A sensible position to take in other words.

Anyway, this next bit is lifted wholesale from another blog called MasterResource, run by Mssrs Bradley and Knappenberger and is here to remind me, or anyone else reading this, that mainstream users of climate models distrust them almost as much as the skeptics:

//////////////////////////////

"Jerry North (Texas A&M) Hints at the Problem

Eleven years ago, when I was director of public policy at Enron, I entered into a consulting agreement with Gerald North, Distinguished Professor of Atmospheric Sciences and Oceanography at Texas A&M’s Department of Atmospheric Sciences, to tell me what was going on. North was as close as I could find to a ‘middle of the roader’ between climate alarmism and (ultra) skepticism. He is alsohighly decorated.

And this has not changed. North’s own intuitive estimate of climate sensitivity is now 50% below the IPCC’s best guess, and he has been critical of a number of the climate mini-alarms that would make headlines and then fade away (more hurricanes, disruption of the thermohaline circulation, etc.).

But I noticed a Malthusian streak in North, that unstated assumption that nature is optimal, and the human influence on climate cannot be good but only bad–and maybe even catastrophic. Still, North in his emails to me–then and now–was rather blunt about the shortcomings of climate modeling.

Here is a sampling of quotations over the last decade:

“There is no doubt a small ‘sociological convergence’ effect, that tends to work here (individuals and their managers hate to be the outlier). The biggest problem is that doubling CO2 leads to a 1 deg C warming (I think even Lindzen agrees). If water vapor doubles it, we are at 2.0 (Lindzen differs here, but I do not know of anyone else). Are there any other feedbacks? It is hard to dismiss ice feedback, but it might be small. Clouds are positive in most models — I have always taken them to be neutral, but with no substantial reason (it’s just easier that way).”

“I do not think there is enough thinking going on. Just plugging in the numbers or running the simulations. Dick [Lindzen] is clearly right on this one.”

“I believe the ocean simulations are very primitive and quite variable from one group to another. The underlying reason is this: How much of the deep layers of the ocean are really participating in the warming?”

“There are pitifully few ways to test climate models.”

“[Models] sort of fake it (we call it ‘parameterization’). They do it in very crude ways such as if the temperature profile of the atmosphere is unstable, they make the whole column overturn, etc.”

“[The models’ treatment of feedbacks] could also be sociological: getting the socially acceptable answer.”

“I go back to my old position: we need more time, maybe a decade to get a better grip on aerosols, water vapor feedback, cloud feedback, ocean participation.”

“We have only a very loose grip on aerosols.”

“[The models] treat the ocean differently. Somehow, they are fudging the parameters that govern ocean coupling so that they get the right ocean delay to agree with the data in spite of their differing sensitivities.”

But before you call North a radical or tattletale on the ‘consensus’, consider what the IPCC said in the back of their latest assessement of the physical science of climate change:

“The set of available models may share fundamental inadequacies, the effects of which cannot be quantified.”

 - IPCC, Climate Change 2007: The Physical Science Basis (Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change). Cambridge, UK: Cambridge University Press, 2007, p. 805.

Is this a trick? Satisfy the science by stating the science–but do so on page 805 rather than in the executive summary where it belongs. It is this sort of thing that Eric Berger–and other open-minded middle-of-the-roaders–are going to find out. And they just might feel a little duped."

///////////////////////////

So OK, North leans towards 1.5K as a likely number, rather than the "official" 3K. Actually the official stance is 1.1 to 6K but everyone just takes the middle of the range as if it was a Gaussian distribution  (it isn't - all numbers higher than 1K are decreasingly scientifically plausible as North admits above - but of course the IPCC like the hoi polloi to assume it's a Gaussian). I've no problem believing that many more scientists think the same way as North but they just don't shout about it in the same way as Lindzen because it's just not politically correct to do so. Not everyones tenure is on such a sound footing as Lindzen, and Spencer actually had to resign from NASA in order to state his skeptical views.

I've noticed that Mathusian streak in a lot of the debate though - particularly on Andy Revkins blog. Overpopulation is a problem easily resolved by allowing 3rd world women some education, some independence and the right to work. All of which arrives with prosperity - which in turn is just possibly dependent on cheap, available energy. Ah...there's the rub. As they said on Spiked magazine though, Malthusians have always been wrong about the limits to growth and the real problem likely isn't too many people, it's too many Malthusians.

Sphere: Related Content