The article discusses the biogeochemical aspects of atmospheric methane, focusing on its role in atmospheric chemistry and climate. Methane is the most abundant organic chemical in Earth's atmosphere and its concentration is increasing. Photochemical reactions oxidize methane, influencing the chemistry of the troposphere and stratosphere, and it is an important greenhouse gas. The paper describes microbial and thermogenic methane production, including key organisms and substrates involved in methanogenesis. It also reviews the oxidation of methane by aerobic and anaerobic bacteria, which limits methane release from certain areas. Isotopic indicators are used to determine the origin of methane. The study evaluates constraints on the budget of atmospheric methane, including sources, sinks, and residence time. The quasi-steady state annual source or sink is estimated at 310 ± 60 × 10¹² mol (500 ± 95 × 10¹² g), but uncertainties remain in source and sink sizes. Methane oxidation affects ozone, hydroxyl radicals, and carbon monoxide concentrations, and it plays a role in the Earth's energy balance. Methane also contributes to climate change by influencing greenhouse gas concentrations and indirectly through the production of CO₂. The paper highlights the importance of understanding methane's role in atmospheric chemistry and climate, as well as the need for further research to better quantify its sources and sinks.The article discusses the biogeochemical aspects of atmospheric methane, focusing on its role in atmospheric chemistry and climate. Methane is the most abundant organic chemical in Earth's atmosphere and its concentration is increasing. Photochemical reactions oxidize methane, influencing the chemistry of the troposphere and stratosphere, and it is an important greenhouse gas. The paper describes microbial and thermogenic methane production, including key organisms and substrates involved in methanogenesis. It also reviews the oxidation of methane by aerobic and anaerobic bacteria, which limits methane release from certain areas. Isotopic indicators are used to determine the origin of methane. The study evaluates constraints on the budget of atmospheric methane, including sources, sinks, and residence time. The quasi-steady state annual source or sink is estimated at 310 ± 60 × 10¹² mol (500 ± 95 × 10¹² g), but uncertainties remain in source and sink sizes. Methane oxidation affects ozone, hydroxyl radicals, and carbon monoxide concentrations, and it plays a role in the Earth's energy balance. Methane also contributes to climate change by influencing greenhouse gas concentrations and indirectly through the production of CO₂. The paper highlights the importance of understanding methane's role in atmospheric chemistry and climate, as well as the need for further research to better quantify its sources and sinks.