Frontiers in Computing: Simulating the World to Predict the Future (scientificamerican.com)

Another article, entitled "Europe's Plan to Simulate the Entire Planet", discusses this issue in slightly more detail, without requiring a subscription. It can be found here: "http://www.technologyreview.com/blog/arxiv/25126/. The actual paper itself can be found at "http://arxiv.org/abs/1004.4969.