[cm2187]

Not sure why you are getting downvoted. It is a fundamental challenge of climate science. You can backtest a model all you want, but anyone familiar with confronting backtested models to reality knows that this gives you very little comfort. Climate science fundamentally deals with untested mathematical models.

It is not the only domain of science that has this problem. Medecine is a big one. You can experiment to some extent but for obvious ethical reasons, there are lots of stuff you can't experiment on, and as a result we keep getting contradictory studies on issues that should be purely factual.