From the Document: "Methane is the world's simplest hydrocarbon, with a chemical formula of CH4 (one atom of carbon and four atoms of hydrogen). It is gaseous under normal atmospheric conditions and is commonly produced through the decomposition of organic materials in the absence of oxygen. It is released into the atmosphere by natural sources such as wetlands, oceans, sediments, termites, volcanoes, and wildfires as well as human activities such as oil and natural gas systems, coal mines, landfills, wastewater treatment facilities, and the raising of livestock. [...] Methane, however, when vented or leaked into the atmosphere (commonly referred to as 'fugitive' emissions), can affect human health and safety and the environment. The U.S. Occupational Safety and Health Administration lists methane as both an asphyxiant and an explosive; increased concentrations in local settings can jeopardize worker safety. Further, the U.S. Environmental Protection Agency (EPA) classifies methane as both a precursor to ground-level ozone formation (commonly referred to as 'smog') and a potent GHG [greenhouse gas], albeit with a shorter atmospheric life than CO2 [carbon dioxide]. Methane's effect on climate change is up to 34 times greater than that of CO2 when averaged over a 100-year time period, and even greater when considered over the first 20 years after it is emitted."
CRS In Focus, IF10752
Congressional Research Service: https://crsreports.congress.gov/