Methane reservoirs on Earth are mainly found in^[1]

• Oil and gas reservoirs as natural gas
• Coalbeds
• the seabed and the Arctic and other permafrost regions as methane clathrate
• the atmosphere
• decaying organic material^[2]

with the exact distribution so far determined by the methane cycle/carbon cycle.

Methane as the main ingredient of natural gas and as an extractable fossil fuel-energy resource has limited if significant reserves. Russia, Iran, and Qatar are topping the list with together 105.6 trillion cubic metres (3.73×10^¹⁵ cu ft), nearly half the world's proven reserves. Methane from gas fields is an important factor in the world energy production and consumption. Methane clathrate is a potential future energy source, if it doesn't escape to the atmosphere before extraction because of global warming. In the atmosphere, it is not only unusable, but also a potent greenhouse gas, further accelerating the current climate change.^[3] But even conventional reservoirs are leaking methane (together with other gases like carbon dioxide) especially downstream the processing line.^[4]