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."

Comments

Do they model supercomputer effects on the Earth?

[Shivetya]

Seems that if each one of these wonders requires a "city-scale" power generation plant that they would have to model themselves into the equation too.

Result: Global Warming is indeed occuring, but apparently it is mainly IBM's fault.

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).

Re:Climate, not weather

[Kynde]

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.

A number of meteorologists are also confusing modelling with scientific modelling. Those larger scale climate models have little chance giving accurate predictions since there's absolutely no reason to assume that such models would not depend chaotically on the underlying small scale weather. Those forementioned fudge factors that climate models are plagued with are manifestation of just that.

Even in more strict science circles people tend to resort to finding trends when the system vanishes out of scope. It's essential that the causality and predictability are present. Otherwise people wind up doing research based crap correlations. For example, for several years there's been really strong correlation between the number of Babtist preachers and number of people arrested for drinking in public. There's jack causality present as the dominant effect is the fluctuations in the population of US.

Just because climate is a lot slower than weather allowing it to predicted for longer periods of time than weather and short term trends give reasonable short term predictions, just as it's possible for weather for a couple of days at a time, it's still chaotic.

It's easy to blow the model out of practicality and show how shitload of CO2 emissions will create greenhouse effect. A lot shittier task is to work with real world figures and again work with a chaotic system. Don't get me wrong though, I'm absolutely all for the Co2 emission regulations and all.

Re:Climate, not weather

[Rogerborg]

• 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

Theory indeed.

• IMB: We've predicted the climate for the next 1000 years!
• Press: Assuming that major vulcanism or meteor impacts don't screw it up, right?
• IBM: Oh, well, sure, assuming that doesn't happen.
• Press: And the chances of that are...?
• IBM: Uhh... about.. ummm... look! Flashing lights! Just like on Star Trek!
• Press: Oooh! Pretty!