Gaseous hydrocarbon. Insoluble in water, under pressure it forms hydrates at low temperatures in water. Geochemically, methane is produced during the formation of coal and petroleum. Recently, it has also been produced under anaerobic conditions by methane-generating bacteria in rice paddies, wetlands, landfills, the stomachs of ruminants, and by certain species of insect (e.g. termites). In the atmosphere, methane is broken down by chemical reactions with alcohol radicals. Methane is an important greenhouse gas and one of the six greenhouse gases to be combated under the Kyoto Protocol. It is the main component of natural gas, is linked to all hydrocarbon fuels, animal husbandry and agriculture, and has a GWP of ca. 28.