Caveat: Climate science has spurred several excellent climate diaries recently. So far as I can tell this is new information.
Anybody running SETI@Home knows the general idea of distributed computing (link), an approach to supercomputing-without-the-supercomputer that just delivered its first major scientific discovery.
As reported in Nature, distributed computing has delivered the largest-scale GCM ever. In fact it delivered several GCMs. Specifically, the authors selected 2,000 individual models capable of predicting current climate from past conditions and then ran each models into the future under various greenhouse predictions. A good number of models before that might be 12.
We're fucked. More on the flip.
Nothing short of modeling a nuclear explosion demands as much silicon as modeling the weather at every point on Earth, beginning a hundred years ago and proceeding in daily increments until a hundred years from now. The last time I checked the best resolution a global climate model (GCM) could get is an Earth composed of blocks several kilometers on a side. Here's what better modeling gets us (all formatting mine):
The greenhouse effect could be far more severe than experts had previously predicted, according to results from the world's biggest climate-modelling study.
In the worst-case scenario, doubling carbon-dioxide levels compared with pre-industrial times increases global temperatures by an average of more than 11 ºC.
...
Previous studies have included only the most probable values for these factors, whereas climateprediction.net's power has allowed the researchers to investigate two or three settings for each parameter.
The project's final predictions are based on the 2,017 simulations that were able to mimic the current climate. All predicted temperature rises. Most were about 3.4 ºC, the average value predicted by the Intergovernmental Panel on Climate Change; many were far more severe.
The researchers plan to improve their models, including a more sophisticated picture of how heat travels through the oceans, regional data and a more accurate picture of how temperatures will change during this century. "There's a huge database of which we've hardly scratched the surface," comments team member Mat Collins of Britain's Met Office in Exeter.
In case anybody has gotten confused by Michael Crichton's recent literary shark-jumping, the experts at RealClimate.com deliver the formal beatdown here and here. Bjorn Lomborg remains an idiot.