Global warming potential
Values
Carbon dioxide has a GWP of exactly 1 (since it is the baseline unit to which all other greenhouse gases are compared).

Global warming potential

Section Title: Values
Table Section Text: Carbon dioxide has a GWP of exactly 1 (since it is the baseline unit to which all other greenhouse gases are compared).

GWP values and lifetimes from 2007 IPCC AR4 p212 (2001 IPCC TAR in parentheses)	Lifetime in years	GWP

20 years	100 years	500 years

Methane	12 (12)	72 (62)	25 (23)	7.6 (7)

Nitrous oxide	114 (114)	289 (275)	298 (296)	153 (156)

HFC-23 (hydrofluorocarbon)	270 (260)	12,000 (9400)	14,800 (12,000)	12,200 (10,000)

HFC-134a (hydrofluorocarbon)	14 (13.8)	3,830 (3,300)	1,430 (1,300)	435 (400)

Sulfur hexafluoride	3200 (3,200)	16,300 (15,100)	22,800 (22,200)	32,600 (32,400)

Sentence(s)

Sulfur hexafluoride has a GWP of 22,800 over 100 years and 16,300 over 20 years (IPCC).

final_sentence: Sulfur hexafluoride has a GWP of 22,800 over 100 years and 16,300 over 20 years (IPCC).