Carbon dioxide from the burning of fossil fuels remains in the atmosphere and is not absorbed by vegetation and the oceans. While transparent to visible light, carbon dioxide is a greenhouse gas, absorbing and emitting infrared radiation at its two infrared-active vibrational frequencies (see the section "Structure and bonding" above). Light emission from the earth's surface is most intense in the infrared region between 200 and 2500 cm, as opposed to light emission from the much hotter sun which is most intense in the visible region. Absorption of infrared light at the vibrational frequencies of atmospheric carbon dioxide traps energy near the
Environmental impact of the coal industry the environment. While these substances are trace impurities, enough coal is burned that significant amounts of these substances are released. During combustion, the reaction between coal and the air produces oxides of carbon, including carbon dioxide (CO, an important greenhouse gas), oxides of sulfur (mainly sulfur dioxide, SO), and various oxides of nitrogen (NO). Because of the hydrogenous and nitrogenous components of coal, hydrides and nitrides of carbon and sulfur are also produced during the combustion of coal in air. These include hydrogen cyanide (HCN), sulfur nitrate (SNO) and other toxic substances. SO and nitrogen oxide react in the atmosphere