cooling will serve to sharpen the debate on whether a climate crisis exists
Not at any science level. We expect to have some years that are cooler and some years that are hotter. To think a hot or cold year by itself signifies anything comes from confusing climate with weather.
Has anyone seen the contrary evidence to this theory yet?
Before I start, let me emphasize that there are many feedback mechanisms out there that we either don't know about, or we suspect are there but aren't sure what will set them off. Some of the feedbacks may help cool things down, others may set things off. Climatologist par excellence
, Wallace Broecker, said
The climate system is an angry beast and we are poking it with sticks.
basing his statement on paleoclimatic reconstructions. He was saying
The earth tends to over-respon...The Earth system has amplifiers and feedbacks that mushroom small impacts into large responses. And what is frustrating is that we are just starting to learn what those amplifiers and feedback mechanisms are.
So it is quite possible there will be some feedback mechanism that will cool the earth down (whether it will do it in any amount of time or in time to do help us out we don't know). And when Lindzen first proposed the Iris Hypothesis (publication 2001) everyone sat up and took notice.
The article linked to in RL post appears to be the Iris Hypothesis again. Here is an overview of Lindzen's work in this 2002 article
, as well as an overview of contrary evidence that came when no-one could replicate his findings. The overview was written in 2002 and the final thought was 'Very interesting. We need more information on this and better studies'.
There have since been many better studies, more reliable measurements, more satellites to measure heat escape etc, and so far there has been no more evidence to support Lindzen's hypothesis. In fact, using the data he used others were getting positive feedbacks rather than his negative feedbacks. In other words the mechanisms he proposes don't cool the temperature but may actually aggravate it (I think part of this is covered in the link above).
See Chapter 8 of the IPCC report page 638 (p. 48 on the pdf version), upper right paragraph
for a list of other research that contradicts Lindzen's findings, and what Lindzen's errors were.
Right now though the Iris Hypothesis looked to be completely debunked so it seems a bit surprising he'd bring it back again. Perhaps he's made some changes to it and fixed up flawed methodology, I don't know. However, it is significant that this newest article is not published in any peer-reviewed journal which may indicate the flaws in his methodology and assumptions have not been corrected.
A 2007 paper by Spencer et al claims to have found support for Lindzen's idea, but according to climatologist Gavin Schmidt...
Spencer et al has nothing to do with the iris effect despite their claims. Their correlations are based on a dynamic mode of variability (the Madden-Julian Oscillation
) which has nothing to do with any SST forced response in the clouds. It's just a bad analogy (rather like using the day-night contrast to estimate climate sensitivity).
SST=sea surface temperature. Apparently this sentiment is shared by the rest of the climatologists who wonder how or why Spencer could get things so wrong (disclaimer--I don't fully understand what the quote means...all I know is that the experts around the world agree with the quote and disagree with Spencer).
Very unfortunately, in recent years Lindzen has gained a reputation for not being totally honest. I say unfortunately because he investigated negative feedbacks (things that might cool the climate), and our understanding advanced. His ideas were investigated and even when wrong the climatologists learned a bit more about how the system worked.
In 2007, Lindzen appeared in a Newsweek article where he was either misquoted/misunderstood quite badly, or he deliberately played fast and loose with the truth. If the former he should have had Newsweek print a correction or retraction because his credibility took a very serious hit. See here
In 2009 at the Heartland Conference (not a conference you want to attend if you value your reputation as a scientist--Czech president and science ignoramus V. Klaus spoke there on something he knew nothing about--climate science) Lindzen infamously said his colleagues endorse climate change to win acclaim
. He goes on to misrepresent Broecker's papers and slanders him by inferring he lies for fame and money (based in part on his (Lindzen's) misinterpretation of Broecker's work). Joseph Romm, a former Acting Assistant Secretary of the US Department of Energy
summed up Lindzen's performance thus...
How pathetic to not merely turn your back on science and the scientific method — but to actually attack the entire community of climate scientists who are working tirelessly to learn the truth and inform the public...That is beyond the pale.
In summary: There are negative feedbacks. They may or may not work in time. The Iris Hypothesis does not appear to be one of these negative feedbacks. Lindzen has lost his credibility as a careful scientist. More research may find additional evidence for other negative feedbacks. More research is needed to know if the unknown negative feedbacks will outweigh the known positive feedbacks. The climate system is an angry beast and we're poking it with sticks.