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
South African gas-electric locomotive experiment. Combustion gases, rich in carbon monoxide and known variously as water gas, producer gas and mond gas, are generated by passing air and steam through some kind of red-hot burning carbonaceous fuel, usually coal. The gas generator consists of a combustion portion, where the fuel is initially burned to generate the required steam. The steam is then blown through this same burning fuel, taking air with it, and the producer gas is then liberated as a by-product of this combustion. Ordinarily, burning produces carbon dioxide, but by forcing steam through the burn a certain amount of incomplete combustion is