"Gas methane" refers to a type of gas that is mainly composed of methane, a colorless and odorless compound. It is commonly found in natural gas and is also produced by animals and human activities. Full definition
By contrast, the powerful greenhouse gas methane is barely mentioned — perhaps because its main sources, while human - related, are «natural»: rice agriculture and cattle - raising. (thenewatlantis.com)
Global oil and gas methane emissions will grow absent further efforts to reduce leakage. (rhg.com)
Scientists have calculated that the present day ice sheets keep vast amounts of climate gas methane in check. (cage.uit.no)