When I used to do this, the models were relatively simple. The earth was little more than blocks representing continents and oceans, there were 7 differential equations representing the atmosphere and you could vary insolation, speed of rotation, various factors. A lot of the complexity now is the earth model itself. The continents aren't simple blocks anymore, but have mountains and other elevations, thermal absorptivity that varies from point to point, and there are a lot of points, and inputs of localized heat sources and I suppose chemicals. And then there were 200 weather stations around the world with any kind of coherent data; now weather satellites dump incomprehensible amounts of data into your model. Todays's models are nearly infinitely more detailed, and I don't believe that including CO
2 in the model is a political choice.
All the same, we shouldn't be moving from computer models to legislation so quickly. We still know next to nothing.
now weather satellites dump incomprehensible amounts of data into your model.The data still has to be high quality, though, or the model results could be totally screwed... er, skewed.