In this contribution, there are given particularities of rumen fermentation in ruminants and the action of greenhouse gases in the atmosphere. Anthropogenic sources of methane are listed here. As an important source of methane, livestock production is mentioned, namely above all breeding of cattle, sheep and goats. In terms of methane production, the proportion of forage and concentrates is very important. Lower production of methane can be gained, among others, by substitution of poor quality forage for high-quality sources of proteins (legumes), easily fermented saccharides, fats, and as well by improvement of the health state of animals, usage of secondary plants metabolites and perspectively by breeding practice. Methane production per unit of animal production gets lower with a higher yield of animals.