Methane leakage
Unintended release of methane from oil, gas and coal supply chains through leaks, venting and incomplete flaring, often expressed as a percentage of gas produced.
Methane is the main component of natural gas and a potent greenhouse gas: GWP100 of 29.8 and GWP20 of about 82.5 for fossil methane (IPCC AR6). Small losses along the supply chain therefore have a large climate effect.
Sources include wellhead and compressor leaks, pneumatic controllers, liquids unloading, tank venting, pipeline blowdowns and incomplete flaring (flares are often assumed 98% efficient, but field studies find lower average destruction). The IEA Global Methane Tracker estimates energy-sector methane at roughly 120–130 Mt per year, about 40% of human methane emissions. A 2018 study (Alvarez et al., Science) put the US oil and gas leakage rate at 2.3%, about 60% higher than the official inventory; satellite surveys of the Permian basin have found rates above 3–4%.
Leakage determines whether gas beats coal. On a 20-year basis, gas-fired power loses its climate advantage over coal at leakage rates of roughly 3–4%; on a 100-year basis the break-even is higher. The EU Methane Regulation (2024) imposes leak detection and repair, bans most routine venting and flaring, and will apply methane intensity standards to imported gas and LNG from 2030.
Related terms
All terms →- Global warming potential (GWP)
The time-integrated radiative forcing of one kilogram of a gas relative to one kilogram of CO2, over a stated period such as 20 or 100 years.
- Natural gas
A fossil fuel composed mainly of methane, used for power generation, industrial and residential heat, and as a chemical feedstock for hydrogen and ammonia.
- LNG (Liquefied Natural Gas)
Natural gas cooled to about minus 162 degrees C, shrinking its volume around 600-fold so it can be shipped by tanker between markets without pipelines.
- Lifecycle emissions
Total greenhouse gas emissions of a product or power source across its full life, from raw material extraction and manufacturing through operation to decommissioning.
- CO2e (CO2 equivalent)
A common unit that expresses emissions of different greenhouse gases as the mass of CO2 that would cause the same warming over a chosen time horizon.