HC Deb 29 January 2002 vol 379 c237W
Mr. Peter Ainsworth

To ask the Secretary of State for Environment, Food and Rural Affairs by what factor each of the other greenhouse gases is more damaging than carbon dioxide. [29616]

Margaret Beckett

The Global Warming Potential (GWP) for each greenhouse gas measures its effectiveness at global warming over the next 100 years compared to CO2. For example, an emission of 1 tonne of methane (CH4) will have a warming effect over the next 100 years that is 21 times greater than the warming produced over that time scale by an emission of 1 tonne of CO2.

The following table shows the UK emissions of the greenhouse gases in 1999 (latest complete annual figures), the GWP of each of the gases and the amount of CO2 that would produce the same warming.

Direct greenhouse gases Emissions in 1999 (kT) GWP (100 years) Equivalent kT of CO2
CO2 (carbon dioxide) 547,800 1 547,800
CH4 (methane) 2632 21 55,266
N20 (nitrous oxide) 138 310 42,890
HFCs (hydrofluorocarbons) 2.749 560–12100 6,206
PFCs (perfluorocarbons) 0.098 6000–7400 678
SF6 (sulphur hexafluoride) 0.055 23900 1,314

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