IEA (2022), Global Methane Tracker 2022, IEA, Paris https://www.iea.org/reports/global-methane-tracker-2022, License: CC BY 4.0
Methane is responsible for around 30% of the rise in global temperatures since the industrial revolution, and rapid and sustained reductions in methane emissions are key to limit near-term warming and improve air quality.
Two key characteristics determine the impact of different greenhouse gases on the climate: the length of time they remain in the atmosphere and their ability to absorb energy. Methane has a much shorter atmospheric lifetime than carbon dioxide (CO2) – around 12 years compared with centuries – but absorbs much more energy while it exists in the atmosphere.
Methane also affects air quality because it can lead to ground level (tropospheric) ozone, a dangerous air pollutant. Methane leaks can also pose explosion hazards.
The concentration of methane in the atmosphere is currently around two-and-a-half times greater than its pre-industrial levels. The increase has accelerated in recent years, and preliminary analysis indicates 2021’s rise is likely to be amongst the largest ever recorded.
Estimates of methane emissions are subject to a high degree of uncertainty, but the most recent comprehensive assessment – provided in the Global Methane Budget – suggests that annual global methane emissions are around 580 Mt. These includes emissions from natural sources (around 40% of emissions), and the remaining 60% which originate from human activity, known as anthropogenic emissions.
The largest anthropogenic source is agriculture, responsible for around one quarter of emissions, closely followed by the energy sector, which includes emissions from coal, oil, natural gas and biofuels.