Increase in the average temperature of the earth's surface, often used to refer to the warming predicted as a result of anthropogenic emissions of greenhouse gases.
Homepage for USGS Global Change Research projects which seek to understand the interrelationships among earth surface processes, ecological systems, and human activities. Links to projects with descriptions and products and downloadable poster.
Site for a USGS project under the U.S. Global Change Research Program for a national assessment of the impacts of climate variability and change on resources with links to impacts in Alaska, western U.S., public lands, and water resources.
Links to USGS activities in the environment theme area, including anthropogenic and natural contaminants, ecosystems, energy, human health, global change, etc. Also includes links to environment-related fact sheets.
Article from American Scientist on study of the San Francisco Bay estuary as a component of the global climate system showing that natural fluctuations might be mistaken for anthropogenic trends affecting waterflow and salinity.