U.S. Department of the InteriorU.S. Geological Survey "Global Change" means changes in the global environment (including alterations in climate, land productivity, oceans or other water resources, atmospheric chemistry, and ecological systems) that may alter the capacity of the Earth to sustain life.
--- Global Change Research Act of 1990
Understanding natural change and the effects of human activities on environmental systems The Earth's global environment--its interrelated climate, land, oceans, fresh water, atmospheric and ecological systems--has changed continually throughout Earth history. Human activities are having ever-increasing effects on these systems. Sustaining our environment as population and demands for resources increase requires a sound understanding of the causes and cycles of natural change and the effects of human activities on the Earth's environmental systems.
The U.S. Global Change Research Program was authorized by Congress in 1989 to provide the scientific understanding necessary to develop national and international policies concerning global environmental issues, particularly global climate change. The program addresses questions such as: what factors determine global climate; have humans already begun to change the global climate; will the climate of the future be very different; what will be the effects of climate change; and how much confidence do we have in our predictions? Through understanding, we can improve our capability to predict change, reduce the adverse effects of human activities, and plan strategies for adapting to natural and human-induced environmental change.
The Department of the Interior manages public lands and other resources across the United States and its territories. Today, a major concern of resource managers is how natural and cultural resources are affected by environmental change, whether it is caused by natural variation or human activities. Department of the Interior research, including studies by the U.S. Geological Survey (USGS), into the effects of global change on sensitive environments and resources provides information necessary for decisions on a variety of environmental issues, including water supplies, ecological systems, and biological diversity.
The USGS studies terrestrial and marine processes and the natural history of global change, including the interactions between climate and the hydrologic system. It is an international source for ground-based and remotely sensed earth science data and information used by global change researchers and contributing to assessments of the potential effects of global change on society. USGS global change research complements research and observations on oceanic, atmospheric, and biological processes in other Federal agencies.