Global warming potential
Also called: GWP · Topic: Climate Change: Causes, Evidence and the Global Response · NCERT: Class 11, Ch 11 "World Climate and Climate Change"
Meaning
Global warming potential (GWP) shows how much heat a greenhouse gas traps compared with carbon dioxide. A greenhouse gas is a gas that holds back the heat the Earth gives off. The comparison uses the same mass of each gas over 100 years, and CO2 is given a GWP of 1. A gas's GWP depends on how strongly it absorbs heat and how long it stays in the air. GWP lets us add up different gases on one scale, called CO2-equivalent.
Example
Methane, released from paddy fields such as those in the Ganga plains, has a GWP of about 28. Nitrous oxide, released from fertilisers, has a GWP of about 270. Chlorofluorocarbons (CFCs), once used in refrigerants and aerosol sprays, have GWPs in the thousands.
Don't confuse with
- Lifetime of a gas: lifetime is how long the gas stays in the air. GWP is how much heat it traps compared with CO2. Methane lasts only about 12 years but still has a high GWP.
Related concepts
- Greenhouse effect
- Greenhouse gases
- Methane
- Nitrous oxide
- Chlorofluorocarbons
- Tropospheric ozone
- Carbon sink
- Climate sensitivity
- Carbon budget