Greenhouse gases absorb infrared radiation emited by the Earth and increase global temperature. Carbon dioxide, metane and water vapour are the primary greenhouse gases. The leading source of metane in agriculture is breeding of farm animals, primarily ruminants and rice fields. This review describes microbial synthesis of metane, interaction of metanogens with other microorganisms and inhibition of metanogens. The lowest production of metane per units of production is in high-production animals