A new report from Global Energy Monitor (GEM) has found that 30 fossil fuel companies produce nearly half (43%) of the industry’s global methane emissions.

Methane is a short-lived greenhouse gas with an average atmospheric lifespan of approximately 12 years, but with much greater warming potential than other greenhouse gases. According to the Intergovernmental Panel on Climate Change (IPCC), methane traps 82.5 times more heat than carbon dioxide (CO2) over 20 years, and 29.8 times more over 100 years.

Cutting methane emissions is widely understood to be one of the cheapest and quickest ways to slow global warming. According to scientists working with the Environmental Defense Fund, prompt action on methane emissions could avert 0.5 degrees of warming before 2100.

The International Energy Agency (IEA) estimates that the coal, oil and gas industries are responsible for 35% of human-induced methane emissions, totalling 126 million tonnes in 2021. GEM’s analysis found that 19 oil and gas companies and 11 coal companies accounted for 54 million tonnes, or 43% of those methane emissions.

The 30 companies with the highest methane emissions are a mix of state-owned and publicly-listed oil and gas companies from more than a dozen countries, as well as state-owned coal companies in China and India.

The National Iranian Oil Company topped the list, emitting 5.9 million tonnes of methane in 2021. Russian oil and gas company Gazprom came in second, emitting 4.1 million tonnes. Three Chinese companies made up the top five, with China Energy (coal) emitting 3.6 million tonnes, Jinneng Group (coal) with 3.5 million tonnes and the China National Petroleum Corporation (oil and gas) with 3.1 million tonnes of methane. See the full list in Table 1 below.

The location of companies’ operations made a significant difference to the volume of methane emissions, likely driven by the condition of infrastructure. For example, the National Iranian Oil Company emitted the most methane emissions, but was only the third largest producer by volume (in barrels of oil equivalent).