Gas generated by the decomposition of organic waste in anaerobic environments, that is, without oxygen. The decomposition process occurs naturally in swamps and also artificially, in sanitary landfills and landfills, because the waste is compressed and there is no oxygen between them. This gas has a calorific value 25 times greater than Carbon Dioxide, which means that it releases much more energy and heat when decomposing than CO2, contributing with greater intensity to Climate Change.