Global warming potential (GWP) is a measure of how much a given mass of greenhouse gas is estimated to contribute to global warming. It is a relative scale which compares the gas in question to that of the same mass of carbon dioxide whose GWP is one.

GWP is defined by the Intergovernmental Panel on Climate Change (IPCC). An exact definition is to be found in their 2001 Third Assessment Report.

Examples:

• carbon dioxide has a GWP of exactly 1 (since it is the baseline unit to which all other greenhouse gases are compared.)
• methane has a GWP of 21
• nitrogen dioxide has a GWP of 310
• the hydrofluorocarbon HFC-23 has a GWP of 11,700
• sulfur hexafluoride (SF₆) has the highest charted GWP of 23,900

External links

• List of Global Warming Potentials and Atmospheric Lifetimes from the U.S. EPA
• IPCC 2001 Third Assessment Report page on Global Warming Potentials