[The_Reader_David]

No, actually, I'm making a point about chaotic dynamics. The models which purport to show anthropogenic global warming are based on too short a time span of data, and are lousy at retrodicting (in which direction they can be tested on the basis of the kind of weak data like tree rings, ice cores, and historical reports) and thus can have no claim for being good at predicting.

I'm always grimly amused at how some wonderfully stable computer models (e.g. the ones the Club of Rome used in Limit to Growth) can be dead wrong despite being based on sound observations. But, they are still scientific theories in Popper's sense. (They just happen to have been falsified, and therefore shown to be wrong scientific theories.)

f.o.g. seems to not like my sociological point about scientific theories (whether good or bad) also becoming religious dogmas for secularists, but wants to deflect it by claiming the bad theories of the anthopogenic global warming crowd aren't scientific theories.

[cogitator]

I'm not sure that you fully comprehended my point. To put it succinctly: GIGO. I.e., you're seeking accurate retrodiction to validate the predictive capability of a climate model, right? To get accurate retrodiction requires accurate historical data. The further you go back in time, the less accurate the historical data becomes. So there's a limit to how accurate your retrodictions can be.

Better is using the models to accurately model recent events, because that data is pretty good. The "Pinatubo test" has been a benchmark -- models had better get the cooling right if they're to be expected to get the warming right, too.

Though it's old, this is still a good article to read: Forcings and Chaos in Global Climate Change

Here are a couple of others:

Greenhouse Gas Influence on Northern Hemisphere Winter Climate Trends

The Sun vs. the Volcano: Drivers of Regional Climate Change (I think you'll appreciate this one)