Earth Simulator Sees Green Light

burbs writes "Big Blue's dominator is getting closer to being turned on. The Earth Simulator in Japan is, supposedly, the world's fastest parallel-processing supercomputer. Designed for the Earth's weather, the computer should be able to predict climate for the entire planet for thousands of years in a short amount of time."

Climate, not weather

[cperciva]

A number of posters are confusing climate modelling with weather prediction. Weather prediction -- working out if it will rain tomorrow -- is very difficult because weather systems are chaotic. Climate prediction, however -- working out how large an effect increased CO2 emmisions will have on global warming -- is easy by comparison... at least in theory.

The problem with climate modelling is that the models right now incorporate large numbers of "fudge factors", and by setting those appropriately you can get whatever outcome you want from your modelling. Of course, without those fudge factors the Earth would be somewhere around -40C most of the time, so you can't just throw them out.

In short, good models exist for weather, but weather is chaotic so you can't predict much anyway. Bad models exist for climate, but at least it isn't chaotic (as far as we know).