Friday, September 9, 2011

The Truth Generally Lies in the Middle

I get criticized for using this cliche on some other blogs. Well, it is a cliche because of a reason, more often than not it is correct. In the global warming debate I am more confident each day it is true. It is not always true though. The goal posts can change without someone gaming the system. Initially, the impact of CO2 enhanced global warming was a compromise. James Hansen predicted 4 degrees of warming, Syukuro Manabe predicted 2 degrees of warming. The range 2 to 4 degrees with the best estimate of 3 is the result of that compromise. Just add a half degree for uncertainty and you have the classic 1.5 to 4.5 range. At that time, the middle was the best truth, 3 degrees.

Times change. The classic 3 degrees was established in 1979, the dawn of the satellite era. It was also the at the beginning the modern warm period. Thirty years later we can see how things have played out.

The compromise is similar to the Monty Hall three door problem. With Hansen's estimate door number one, Manabe's estimate door number three and in the middle is the IPCC with door number two. Each had a possibility of being right, a 1/3 probability. Since the models thirty years later are leaning towards Manabe or IPCC, Hansen's door seems to have the booby prize. So where's the car?

If you picked door number two first, the is a little bit better chance it is behind door number three. If you picked door number three first, there is a little bit better chance it is behind door number two. Do you switch your door?

That is were the Global Warming debate is, door two or door three. So there is still a 50% chance the truth is in the middle, but if your first choice was the middle, you should think about changing.

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