The latest scientific data confirm that the earth's climate is rapidly changing. Global temperatures increased by about 1 degree Fahrenheit over the course of the last century, and will likely rise even more rapidly in coming decades. The cause? A thickening layer of carbon dioxide pollution and other greenhouse gases, mostly from power plants and automobiles, which traps heat in the atmosphere. The Intergovernmental Panel on Climate Change (IPCC), a group of the world's leading climate researchers, sees a greater than 90 percent likelihood that most warming over the last 50 years has occurred because of human-caused emissions of heat-trapping greenhouse gases.