U.S. Global Change Research Project
"helping understand, assess, and predict global change..."
Focused on the far-reaching impact of climate change on the United States and the world, the Global Change Research Program website brings together research on change from international partners and many governmental agencies, including the Agency for International Development, the National Oceanographic and Atmospheric Administration, the US Geological Survey, NASA, the Environmental Protection Agency, the National Science Foundation, the Smithsonian, the National Institutes of Health, and cabinet departments of Agriculture, Defense, Energy, Health and Human Services, Interior, State, and Transportation.
The latest — improved — website contains a useful library of documents (many available for download), an events listing, and a wealth of links to related sources.