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.
Global warming potential compares how much energy a pulse emission of a gas traps in the climate system over a given horizon, relative to the same mass of CO2 (GWP = 1 by definition).
Selected IPCC AR6 (2021) values:
- Methane (fossil): GWP100 29.8, GWP20 82.5; biogenic methane GWP100 27.0
- Nitrous oxide: GWP100 273
- HFC-134a: GWP100 1,530
- SF6: GWP100 about 25,200
Gas lifetimes drive the difference between horizons. Methane decays in about 12 years, so its potency falls steeply when averaged over a century; CO2 has no single lifetime and a fraction persists for millennia. Alternative metrics exist: GTP (global temperature change potential) and GWP* (which treats a constant methane emission rate as roughly equivalent to a one-off CO2 pulse), but GWP100 remains the standard in UNFCCC inventories and in CO2e accounting for corporate Scope 1 reporting.
Related terms
All terms →- 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.
- 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.
- Scope 1 emissions
Direct greenhouse gas emissions from sources owned or controlled by a reporting organisation, such as boilers, furnaces, vehicles and process emissions.
- Carbon budget
The cumulative amount of CO2 that can still be emitted while keeping global warming below a given limit with a stated probability.