2006-04-19

Alarmists! Alarmists!

I haven't posted a response to Richard Lindzen's op-ed in the Wall Street Journal [LINK]. The main reason is that I'm really not fast enough to beat the folks at RealClimate [LINK], who do an outstanding job of addressing the scientific points of these kinds of things. Definitely read the op-ed, take a drink to wash that bad taste away, and then go read the posts at RealClimate. Today, Jeff Masters at wunderground.com has taken a swing at the Lindzen piece, and done a really nice job [LINK].

As a recap, the Lindzen rant is basically saying that there are all kinds of "alarmist" climate scientists who rely on the public being afraid of global warming in order to get funding to, you guessed it, study global warming. This idea has been around almost as long as the global warming deniers have. (By the way, I am not going to use the word 'skeptic' for these folks, since I think being skeptical is a virtue and relates to having an open mind and rational thought process. The deniers are closing their minds to basic scientific principles, and have ceased to be skeptical.) The problem with the idea that climate science is self-perpetuating is that it can't really be true. If it were, and this response is now standard among climate scientists addressing the question, climate scientists would be encouraging much more investment in climate research, but instead the most "alarmist" among us are calling for huge investments in energy research and mitigation strategies. That doesn't sound like self-interested activity to me. There are a few other points in Lindzen's rant, but you can read more about that elsewhere.

As a point of clarification, in case you go read Jeff Master's post, the description of Lindzen's iris hypothesis is not correct there. The idea behind the iris hypothesis is that precipitation efficiency (how much of evaporated water in tropical convection gets rained out versus deposited in the upper troposphere) will increase in a warming environment, which would have the effect of reducing the area covered by cirrus anvils. That would essentially let more terrestrial infrared radiation escape to space (in the tropics) and be a cooling influence on the climate, like the iris of the eye opening and closing to change the amount of light passing through. The problems with this theory are numerous, actually, though it can not yet be completely discredited. The main problem is that there is no evidence for this change in precipitation efficiency, either from observations or simulations. It is still a possibility, and if it were ever to be found in nature, it is likely that climate models would have to incorporate a new microphysics parameterization because this effect is not currently modeled. Other criticisms have pointed out errors with the statistical methods Lindzen and colleagues used in the original paper, as well as ambiguities between local and nonlocal effects.

references

iris hypothesis paper (Lindzen et al)
statistical response (Harrison)
local v. nonlocal effects (Hartmann & Michelsen)
Obervational study to test iris hypothesis (Lin et al)

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