Global warming potential

Global warming potential (GWP) measures how much heat a greenhouse gas (GHG) traps in the atmosphere. All the GHGs measured are relative to CO2, which has a value of 1. The higher the GWP, the more heat a gas traps, therefore, the higher the GWP the more harm it has on the climate.

The chart below does not take into account the complicated factors involved on how long a gas stays in the atmosphere. For example, CO2 has a much longer residence time than methane, decreasing the gap between them of how much heat they will trap in their respective lifetimes.

Common GWP values[1][2]

Gas Chemical formula Atmospheric lifetime (years) GWP value
Carbon dioxide CO2 -* 1
Methane CH4 12 21
Nitrous oxide N2O 114 310
Ammonia NH3 <2 hours 0
Nitrogen trifluoride NF3 740 10,970

*Calculating the atmospheric lifetime of CO2 is extremely complex. If you'd like to learn about it, click here.

For Further Reading


  1. "2.10.2 Direct Global Warming Potentials - AR4 WGI Chapter 2: Changes in Atmospheric Constituents and in Radiative Forcing",, 2018. [Online]. Available: [Accessed: 13- Jul- 2018].
  2. "Ozone Layer Protection | US EPA", US EPA, 2018. [Online]. Available: [Accessed: 13- Jul- 2018].