IPCC list of greenhouse gases

The radiative forcing (warming influence) of long-lived atmospheric greenhouse gases has accelerated, almost doubling in 40 years.

This is a list of the most influential long-lived, well-mixed greenhouse gases, along with their tropospheric concentrations and direct radiative forcings, as identified by the Intergovernmental Panel on Climate Change (IPCC). Abundances of these trace gases are regularly measured by atmospheric scientists from samples collected throughout the world. Since the 1980s, their forcing contributions (relative to year 1750) are also estimated with high accuracy using IPCC-recommended expressions derived from radiative transfer models.

This list excludes:

  • water vapor which is responsible overall for about half of all atmospheric gas forcing. Water vapor and clouds are more dynamic atmospheric constituents and contribute strong climate change feedback influences.
  • other short-lived gases (e.g. carbon monoxide, NOx) and aerosols (e.g. mineral dust, black carbon) that also vary more strongly over location and time. Ozone has warming influences comparable to nitrous oxide and CFCs, and is longer lived and more abundant in the stratosphere than in the troposphere.
  • many refrigerants and other halogenated gases that have been mass-produced in smaller quantities. Most are long-lived and well-mixed. Some are also listed in Appendix 8A of the 2013 IPCC Assessment Report. and Annex III of the 2021 IPCC WG1 Report
  • oxygen, nitrogen, argon, and other gases that are less influenced by human activity and interact relatively little with Earth's thermal radiation.


Combined Summary from IPCC Assessment Reports (TAR, AR4, AR5, AR6)

Mole fractions: μmol/mol = ppm = parts per million (106); nmol/mol = ppb = parts per billion (109); pmol/mol = ppt = parts per trillion (1012).

Species Lifetime
(years)
 100-yr
GWP
 Mole Fraction [ppt - except as noted] Radiative forcing [W m−2]
Base
1750 		TAR
1998 		AR4
2005 		AR5
2011 		Data
2020 		TAR
1998 		AR4
2005 		AR5
2011 		AR6
2019
CO2 [ppm] 1 278 365 379 391 1.46 1.66 1.82 2.16
CH4 [ppb] 12.4 28 700 1,745 1,774 1,801 0.48 0.48 0.48 0.54
N2O [ppb] 121 265 270 314 319 324 0.15 0.16 0.17 0.21
CFC-11 45 4,660 0 268 251 238 0.07 0.063 0.062 0.066
CFC-12 100 10,200 0 533 538 528 0.17 0.17 0.17 0.18
CFC-13 640 13,900 0 4 - 2.7 cfc13 0.001 - 0.0007 0.0009
CFC-113 85 6,490 0 84 79 74 0.03 0.024 0.022 0.021
CFC-114 190 7,710 0 15 - - cfc114 0.005 - - 0.005
CFC-115 1,020 5,860 0 7 - 8.37 cfc115 0.001 - 0.0017 0.0021
HCFC-22 11.9 5,280 0 132 169 213 0.03 0.033 0.0447 0.0528
HCFC-141b 9.2 2,550 0 10 18 21.4 0.001 0.0025 0.0034 0.0039
HCFC-142b 17.2 5,020 0 11 15 21.2 0.002 0.0031 0.0040 0.0043
CH3CCl3 5 160 0 69 19 6.32 0.004 0.0011 0.0004 0.0001
CCl4 26 1,730 0 102 93 85.8 0.01 0.012 0.0146 0.0129
HFC-23 222 12,400 0 14 18 24 0.002 0.0033 0.0043 0.0062
HFC-32 5.2 677 0 - - 4.92 - - 0.0005 0.0022
HFC-125 28.2 3,170 0 - 3.7 9.58 - 0.0009 0.0022 0.0069
HFC-134a 13.4 1,300 0 7.5 35 62.7 0.001 0.0055 0.0100 0.018
HFC-143a 47.1 4,800 0 - - 12.0 - - 0.0019 0.0040
HFC-152a 1.5 138 0 0.5 3.9 6.4 0.000 0.0004 0.0006 0.0007
CF4 (PFC-14) 50,000 6,630 40 80 74 79 0.003 0.0034 0.0040 0.0051
C2F6 (PFC-116) 10,000 11,100 0 3 2.9 4.16 0.001 0.0008 0.0010 0.0013
SF6 3,200 23,500 0 4.2 5.6 7.28 0.002 0.0029 0.0041 0.0056
SO2F2 36 4,090 0 - - 1.71 - - 0.0003 0.0005
NF3 500 16,100 0 - - 0.9 - - 0.0002 0.0004

A The IPCC states that "no single atmospheric lifetime can be given" for CO2. This is mostly due to the rapid growth and cumulative magnitude of the disturbances to Earth's carbon cycle by the geologic extraction and burning of fossil carbon. As of year 2014, fossil CO2 emitted as a theoretical 10 to 100 GtC pulse on top of the existing atmospheric concentration was expected to be 50% removed by land vegetation and ocean sinks in less than about a century, as based on the projections of coupled models referenced in the AR5 assessment. A substantial fraction (20-35%) was also projected to remain in the atmosphere for centuries to millennia, where fractional persistence increases with pulse size.
B Values are relative to year 1750. AR6 reports the effective radiative forcing which includes effects of rapid adjustments in the atmosphere and at the surface.

Gases from IPCC Fourth Assessment Report

The following table has its sources in Chapter 2, p. 141, Table 2.1. of the IPCC Fourth Assessment Report, Climate Change 2007 (AR4), Working Group 1 Report, The Physical Science Basis.

Mole fractions and their changes Radiative forcing
Species 2005 Change since 1998 2005 (W m−2) 1998 (%)
CO2 379 ± 0.65 μmol/mol +13 μmol/mol 1.66 +13
CH4 1,774 ± 1.8 nmol/mol +11 nmol/mol 0.48 –
N2O 319 ± 0.12 nmol/mol +5 nmol/mol 0.16 +11
CFC-11 251 ± 0.36 pmol/mol −13 0.063 −5
CFC-12 538 ± 0.18 pmol/mol +4 0.17 +1
CFC-113 79 ± 0.064 pmol/mol −4 0.024 −5
HCFC-22 169 ± 1.0 pmol/mol +38 0.033 +29
HCFC-141b 18 ± 0.068 pmol/mol +9 0.0025 +93
HCFC-142b 15 ± 0.13 pmol/mol +6 0.0031 +57
CH3CCl3 19 ± 0.47 pmol/mol −47 0.0011 −72
CCl4 93 ± 0.17 pmol/mol −7 0.012 −7
HFC-125 3.7 ± 0.10 pmol/mol +2.6 0.0009 +234
HFC-134a 35 ± 0.73 pmol/mol +27 0.0055 +349
HFC-152a 3.9 ± 0.11 pmol/mol +2.4 0.0004 +151
HFC-23 18 ± 0.12 pmol/mol +4 0.0033 +29
SF6 5.6 ± 0.038 pmol/mol +1.5 0.0029 +36
CF4 (PFC-14) 74 ± 1.6 pmol/mol – 0.0034 –
C2F6 (PFC-116) 2.9 ± 0.025 pmol/mol +0.5 0.0008 +22

Gases from IPCC Third Assessment Report

The following table has its sources in Chapter 6, p. 358, Table 6.1. of the IPCC Third Assessment Report, Climate Change 2001 (TAR), Working Group 1, The Scientific Basis.

Gases relevant to radiative forcing only

Gas Alternate name Formula 1998 level Increase since 1750 Radiative forcing (Wm−2) Specific heat at STP
(J kg−1)
Carbon dioxide Carbon Dioxide (CO2) 365 μmol/mol 87 μmol/mol 1.46 0.819
Methane Marsh gas (CH4) 1,745 nmol/mol 1,045 nmol/mol 0.48 2.191
Nitrous oxide Laughing gas (N2O) 314 nmol/mol 44 nmol/mol 0.15 0.88
Tetrafluoromethane Carbon tetrafluoride (CF4) 80 pmol/mol 40 pmol/mol 0.003 1.33
Hexafluoroethane Perfluoroethane (C2F6) 3 pmol/mol 3 pmol/mol 0.001 0.067
Sulfur hexafluoride Sulfur fluoride (SF6) 4.2 pmol/mol 4.2 pmol/mol 0.002 0.074
HFC-23 Trifluoromethane (CHF3) 14 pmol/mol 14 pmol/mol 0.002 0.064
HFC-134a 1,1,1,2-Tetrafluoroethane C2H2F4 7.5 pmol/mol 7.5 pmol/mol 0.001 0.007
HFC-152a 1,1-Difluoroethane (C2H4F2) 0.5 pmol/mol 0.5 pmol/mol 0.000 0.04

Gases relevant to radiative forcing and ozone depletion

Gas Alternate name Formula 1998 level Increase since 1750 Radiative forcing
(Wm−2)
CFC-11§ Trichlorofluoromethane (CFCl3) 268 pmol/mol 268 pmol/mol 0.07
CFC-12§ Dichlorodifluoromethane (CF2Cl2) 533 pmol/mol 533 pmol/mol 0.17
CFC-13§ Chlorotrifluoromethane (CClF3) 4 pmol/mol 4 pmol/mol 0.001
CFC-113 1,1,1-Trichlorotrifluoroethane (C2F3Cl3) 84 pmol/mol 84 pmol/mol 0.03
CFC-114 1,2-Dichlorotetrafluoroethane (C2F4Cl2) 15 pmol/mol 15 pmol/mol 0.005
CFC-115 Chloropentafluoroethane (C2F5Cl) 7 pmol/mol 7 pmol/mol 0.001
Carbon tetrachloride Tetrachloromethane (CCl4) 102 pmol/mol 102 pmol/mol 0.01
1,1,1-Trichloroethane Methyl chloroform (CH3CCl3) 69 pmol/mol 69 pmol/mol 0.004
HCFC-141b 1,1-Dichloro-1-fluoroethane (C2H3FCl2) 10 pmol/mol 10 pmol/mol 0.001
HCFC-142b 1-Chloro-1,1-difluoroethane (C2H3F2Cl) 11 pmol/mol 11 pmol/mol 0.002
Halon-1211 Bromochlorodifluoromethane (CClF2Br) 3.8 pmol/mol 3.8 pmol/mol 0.001
Halon-1301 Bromotrifluoromethane (CF3Br) 2.5 pmol/mol 2.5 pmol/mol 0.001

See also