The primary contributors to atmospheric methane are natural processes, livestock farming, and the fossil fuel industry.

Methane is a highly potent greenhouse gas emitted from various sources. Among the most significant natural sources are wetlands—areas of land that are saturated with water, either temporarily or permanently. The anaerobic (oxygen-free) conditions found in wetlands create an ideal environment for methane-producing microorganisms known as methanogens. These microorganisms decompose organic matter without oxygen, resulting in the release of methane as a by-product.

Another major source of methane is livestock farming. Ruminant animals, such as cows and sheep, produce methane during their digestion. This occurs because these animals possess a specialized stomach that enables them to break down plant materials that most other animals cannot digest. The process, referred to as enteric fermentation, produces methane, which is subsequently released into the atmosphere through belching and flatulence.

The fossil fuel industry is also a significant source of methane emissions. This encompasses the extraction, processing, and distribution of coal, oil, and natural gas. Methane can be released during these operations either intentionally, through venting, or unintentionally, through leaks. While methane is emitted during the combustion of fossil fuels, this represents a smaller contribution compared to the other sources mentioned.

In addition to these primary sources, other contributors to methane emissions include rice cultivation, biomass burning, and waste management. In rice cultivation, flooded fields create anaerobic conditions similar to those found in wetlands, which leads to methane production. Biomass burning, such as forest fires and the incineration of agricultural waste, also releases methane. Lastly, waste management practices, including landfills and waste treatment facilities, generate methane as organic waste decomposes.