Direct Global Warming Potentials

Relative to Carbon Dioxide

Direct Global Warming Potentials (GWPs) relative to carbon dioxide (for gases for which the lifetimes have been adequately characterised). GWPs calculated for different time horizons show the effects of atmospheric lifetimes of the different gases.
Gas Chemical Formula Lifetime
(years)
Global Warming Potential
(Time Horizon in years)
20 yrs
100 yrs
500 yrs
Carbon Dioxide
CO2
1
1
1
Methanea
CH4
12.0b
62
23
7
Nitrous Oxide
N2O
114b
275
296
156
*CFC-11
55
4500
3400
1400
*CFC-12
116
7100
7100
4100
*CFC-13
400
11000
13000
15000
*CFC-14
>500
>3500
>4500
>5300
*HCFC-22
15.8
4200
1600
540
*CFC-113
110
4600
4500
2500
*CFC-114
220
6100
7000
5800
*CFC-115
550
5500
7000
8500
*CFC-116
>500
>4800
>6200
>7200

Hydrofluorocarbons
HFC-23
CHF3
260
9400
12000
10000
HFC-32
CH2F2
5.0
1800
550
170
HFC-41
CH3F
2.6
330
97
30

HFC-125

CHF2CF3

29

5900

3400

1100
HFC-134
CHF2CHF2
9.6
3200
1100
330
HFC-134a
CH2FCF3
13.8
3300
1300
400
HFC-143
CHF2CH2F
3.4
1100
330
100
HFC-143a
CF3CH3
52
5500
4300
1600

HFC-227ea

CF3CHFCF3

33

5600

3500

1100
HFC-236cb
CH2FCF2CF3
13.2
3300
1300
390
HFC-236ea
CHF2CHFCF3
10
3600
1200
390
HFC-236fa
CF3CH2CF3
220
7500
9400
7100
Fully fluorinated species
SF6
3200
15100
22200
32400
CF4
50000
3900
5700
8900
C2F6
10000
8000
11900
18000
C3F8
2600
5900
8600
12400
aThe methane GWPs include an indirect contribution from stratospheric H2O and O3 production.
bThe values for methane and nitrous oxide are adjustment times, which incorporate the indirect effects of emission of each gas on its own lifetime.
Adapted from IPCC, 2001: Climate Change 2001: Synthesis Report. A contribution of Working Groups I, II, and III to the Third Assessment Report of the Intergovernmental Panel on Climate Change [Watson, R.T. and the Core Writing Team (eds.)]. Cambridge University Press, Cambridge, United Kingdom, and New York, NY, USA, 398 pp.
*Adapted from Houghton, J.T., Climate Change 1992. Cambridge University Press.