Methane is the second most important greenhouse gas (GHG), tonne per tonne it is 82.5 times more potent than carbon dioxide (CO2) over a 20-year period and responsible for a quarter of the warming that has occurred so far. Methane emissions also contribute to the formation of tropospheric ozone, a harmful air pollutant responsible for one million premature deaths every year. Reducing methane emissions is essential in the fight to limit temperature increase to 1.5°C in line with the Paris Agreement, while such action will also have important benefits for natural ecosystems, agricultural yields and human health.
The concentration of methane in the atmosphere has more than doubled since pre-industrial times and is projected to continue to increase through at least 2040. Current methane concentrations are too high to meet even the 2°C scenarios laid out by the Intergovernmental Panel on Climate Change (IPCC).
More than half of global methane emissions are human caused, predominantly from the energy (oil, gas and coal), agriculture (livestock) and waste sectors (landfill and wastewater). In the energy sector, methane is released into the atmosphere through routine venting and flaring and leakage across the oil and gas supply chain while abandoned and unused oil, gas and coal sites often emit methane unabated. Fossil gas (often known by the misnomer ‘natural gas’) used in petrochemicals to produce plastic is an important source of methane.
Adding to the urgency, vast deposits of methane stored under layers of permafrost are at increasing risk of being released as the planet warms and the permafrost thaws. This climate ‘tipping point’ would be catastrophic with the potential to release hundreds of billions of tonnes of carbon-dioxide equivalent (CO2e) into the atmosphere causing dramatic warming. Fast action on short-lived climate pollutants, such as methane and fluorinated GHGs (F-gases), greatly increases our chances of flattening the climate curve and avoiding these climate tipping points.