Climate Change

A long-term shift in climate measured by changes in temperature, precipitation, winds, and other indicators. Climate change can involve both changes in average conditions and changes in variability, including, for example, changes in extreme conditions. Climate change can be caused by both natural processes and human activities, in particular those that alter the chemical composition of the atmosphere. The buildup of greenhouse gases in the atmosphere is the primary cause for concern about climate change now and into the immediate future. Particularly important is the increase in atmospheric carbon dioxide, which is released through the combustion of fossil fuels.