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).[4] Abundances of these trace gases are regularly measured by atmospheric scientists from samples collected throughout the world.[5][6][7] 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.[3]
This list excludes:
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) [4]:731 |
100-yr GWP [4]:731 |
Mole Fraction [ppt - except as noted] | Radiative forcing [W m−2] [B] | |||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Base 1750 |
TAR[13] 1998 |
AR4[14] 2005 |
AR5[4]:678 2011 |
Data[15][16] 2020 |
TAR[13] 1998 |
AR4[14] 2005 |
AR5[4]:678 2011 |
AR6[10]:4-9 2019 | |||
CO2 [ppm] | [A] | 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.[4]:731 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.[17] 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.[18] A substantial fraction (20-35%) was also projected to remain in the atmosphere for centuries to millennia, where fractional persistence increases with pulse size.[19][20]
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.[21]
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.[14]
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 |
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.[13]
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 |
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 |