Methane: A greenhouse gas in the Earth's atmosphere

Methane is an atmospheric trace gas, which influences numerous chemical processes and species in the troposphere and stratosphere. It makes a significant adverse contribution to the ‘greenhouse’ phenomenon. Its global concentration in the atmosphere has been rising since the start of the Industrial Revolution ( ∼ 300 years ago), before which the concentration was almost constant at about 0·65 ppmv. In 1990, it reached 1·72 ppmv. In this paper, the history of methane in the Earth's atmosphere, together with its latitudinal and altitudinal distributions and seasonal fluctuations, are described.