Atmospheric levels of carbon dioxide belched out by cars and power plants soar, while amphibian populations plummet and glaciers dwindle like an ice cube in your palm. These are just three examples of global change, a term used to describe climate trends and other environmental transformations. Disbursing the U.S. government's sprawling Earth data stockpile is the aim of the federal Global Change Data and Information System .
The centerpiece of the site is a catalogue, organized by key words like a Yahoo directory, of some 8000 databases spanning earth sciences to ecology. They range from LANDSAT images of land use in the Chesapeake Basin, to fish catches off California since the 1920s, to 400,000 years of global temperature estimates from antarctic ice cores. Visitors can also leaf through new government reports, such as one on the water shortages that greenhouse warming could bring; or follow links to field projects, such as a long-term ecological monitoring station in the New Mexico desert. The site also offers links to journal articles and press releases on new research.
Or the curious can direct a question to Dr. Climate Change, the site's most popular feature. While dealing with the occasional bizarre query--one recent visitor asked about the feasibility of building a dam across the Strait of Gibraltar--agency specialists aim to answer each serious question within 3 days.