Atmospheric methane

Atmospheric Methane

Atmospheric methane is a potent greenhouse gas with significant implications for climate change and environmental science. It is the second most abundant anthropogenic greenhouse gas after carbon dioxide, contributing to global warming and climate change.

Sources of Atmospheric Methane

Methane is released into the atmosphere from both natural and anthropogenic sources.

Natural Sources

• Wetlands: Wetlands are the largest natural source of methane, where anaerobic decomposition of organic material occurs.
• Termites: Termites produce methane during the digestion of cellulose.
• Oceans: Methane is released from the ocean floor and through biological processes in the water column.
• Permafrost: Thawing permafrost releases methane trapped in ice.

Anthropogenic Sources

• Agriculture: Livestock digestion and rice paddies are significant sources of methane emissions.
• Fossil Fuels: Extraction and burning of fossil fuels, such as coal, oil, and natural gas, release methane.
• Landfills: Decomposition of organic waste in landfills produces methane.
• Biomass Burning: Burning of organic matter releases methane.

Atmospheric Chemistry and Lifetime

Methane has a relatively short atmospheric lifetime of about 9-12 years. It is removed from the atmosphere primarily through reaction with hydroxyl radicals (OH) in the troposphere, forming water vapor and carbon dioxide.

Impact on Climate

Methane is a powerful greenhouse gas, with a global warming potential approximately 28-36 times greater than that of carbon dioxide over a 100-year period. It absorbs infrared radiation, trapping heat in the atmosphere and contributing to the greenhouse effect.

Mitigation Strategies

Efforts to reduce atmospheric methane include:

• Improving agricultural practices: Enhancing feed efficiency and manure management in livestock.
• Capturing landfill gas: Utilizing methane from landfills as an energy source.
• Reducing fossil fuel emissions: Implementing technologies to capture methane during extraction and transport.
• Restoring wetlands: Managing water levels to reduce methane emissions.

Also see

• Greenhouse gas
• Climate change
• Carbon dioxide
• Global warming potential
• Methane clathrate