Greenhouse gas emissions by the United States of Energy's Energy Information Administration (EIA). Electricity generation increased by 2.5%, and carbon dioxide emissions from the power sector increased even more, at 3%, indicating that U.S. utilities shifted towards energy sources that emitted more carbon. That shift was partially caused by a 40 billion kilowatt-hour decrease in hydropower production causing a greater reliance on fossil fuels like natural gas and coal. Carbon dioxide emissions from power plants fueled with natural gas increased by 10.5%, while coal-burning power plants increased their emissions by 1.8%. Paper is the fourth largest contributor to greenhouse gas emissions in the United States and one
Carbon dioxide Carbon dioxide Carbon dioxide (chemical formula ) is a colorless gas with a density about 60% higher than that of dry air. Carbon dioxide consists of a carbon atom covalently double bonded to two oxygen atoms. It occurs naturally in Earth's atmosphere as a trace gas. The current concentration is about 0.04% (410 ppm) by volume, having risen from pre-industrial levels of 280 ppm. Natural sources include volcanoes, hot springs and geysers, and it is freed from carbonate rocks by dissolution in water and acids. Because carbon dioxide is soluble in water, it occurs naturally in groundwater, rivers and lakes,