COTD #N: Another Thing

clipped from chicagoboyz.net Here’s another thing. The mathematics of dynamic systems, particularly the stocastic element, is surprisingly complicated, and most climate researchers are largely ignorant of it. I read a paper by James Hansen in which he used a variety of data sources to show that positive derivative (sensitivity) of global temperature to increased CO2. The implication, he seemed to assert, was that the asymptotic temperature would therefore be higher. This, from a dynamical system point of view, is demonstrably wrong. Even a type of relatively simple linear system – the so-called non-minimum phase system – can show an instantaneous positive derivative to an input, but have an overall decrease in that variable. Unfortunately, no one knows enough about the dynamic nature of the earth’s climate system to be able to definitively assert what the asymptotics will be. In fact, my impression is that most of the models are static energy-balance types of models – yet another factor in my skepticism.

RTWT.