[extropy-chat] A Bayesian Looks at Climate Change

[Eliezer S. Yudkowsky]

Hal Finney wrote:
> I ran into an amazing blog entry from last month which sheds new light
> on global warming from an unusual perspective:
> http://julesandjames.blogspot.com/2006/03/climate-sensitivity-is-3c.html
> The blog entry is by James Annan and describes a paper he coauthored with
> J.C. Hargreaves that is being published in Geophysical Research Letters:
> http://www.jamstec.go.jp/frcgc/research/d5/jdannan/GRL_sensitivity.pdf
> 
> The bottom line is that when you combine all these different papers
> using Bayesian analysis, you get that climate sensitivity is 3 +/- 0.5
> degrees C, an astonishingly narrow estimate given the state of knowledge
> in the field.

This sounds highly suspicious to me.  What if there are correlated 
errors in the studies?

No one in China has ever seen the Emperor of China, but everyone can 
guess his height to within plus or minus one meter.  Therefore, by 
polling a million Chinese and averaging their estimates, the law of 
large numbers says we can get an estimate of the Emperor's height that 
is accurate to within one millimeter.

-- 
Eliezer S. Yudkowsky                          http://singinst.org/
Research Fellow, Singularity Institute for Artificial Intelligence