Yes, methane is a greenhouse gas about 27-30 times more powerful than carbon dioxide at warming the Earth, on a 100-year timescale, and more than 80 times more powerful over 20 years (IPCC AR6, 2021)!
Although methane (CH₄) remains in the atmosphere for less time than carbon dioxide (CO₂) (about 10 years), methane absorbs much more energy, enhancing its contribution to the Earth’s greenhouse effect.
The metric used to compare greenhouse gases (GHG) is the Global Warming Potential (GWP), which uses CO₂ as the reference gas for the analysis.
GHGs heat the Earth by captivating energy and decreasing the rate at which energy escapes into space; they create a blanket that isolates our planet. Different GHGs can also have different results in global warming. These gases differ in two ways: the ability to absorb energy (their “radiative efficiency”) and the time they remain in the atmosphere (also known as “lifetime”).
The GWP measures how much energy emissions of a tonne of a gas will absorb in a given period, compared to emissions of a tonne of CO₂. The higher the GWP of a particular gas, the more it will heat the Earth compared to CO₂ over time. The period generally used for GWP is 100 years.
CO₂, as the reference gas, has a GWP of one regardless of the time used. The CO₂ residence time in the atmosphere is thousands of years.