<unk> es are the<unk> es present in the atmosphere which reduce the loss of heat into space and therefore contribute to global temperatures through the<unk>  effect.<unk> es are essential to maintaining the temperature of the Earth; without them the planet would be so cold as to be uninhabitable. However, an excess of<unk> es can raise the temperature of a planet to lethal levels, as on Venus where the 96.5% carbon dioxide (CO2) atmosphere results in surface temperatures of about  467 °C (872 °F).<unk> es are produced by many natural and industrial processes, which currently result in CO2 levels of 380 ppmv in the atmosphere. Based on ice-core samples and records (see graphs) current levels of CO2 are approximately 100 ppmv higher than during immediately pre-industrial times, when direct human influence was negligible.
Greenhouse gas
Ether
Syngas
Acrolein
Peroxide
Carbon dioxide
Hydrocarbon
Carbide