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PUBLISHED MODELS, CITED MEASUREMENTS
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DATA STATUS
417 series loaded · last import on 2026-10-25

Greenhouse gases CO₂, methane, nitrous oxide and SF₆ measured by the NOAA global network, and their radiative forcing

Global CO₂, latest month
426.10 ± 0.10 ppm
2026-07
provisional value
 
Global monthly mean CO₂ at the marine surface sites (NOAA GML) · U.S. Government work, public domain; cite the NOAA GML trend data set · 10/25/26 Current · provisional
Global CH₄, latest month
1,934.6 ppb
2026-06
provisional value
 
Global monthly mean CH₄ at the marine surface sites (NOAA GML) · U.S. Government work, public domain; cite the NOAA GML trend data set · 10/25/26 Current · provisional
Global N₂O, latest month
339.86 ppb
2026-06
provisional value
 
Global monthly mean N₂O at the marine surface sites (NOAA GML) · U.S. Government work, public domain; cite the NOAA GML trend data set · 10/25/26 Current · provisional
Global SF₆, latest month
12.73 ppt
2026-06
provisional value
 
Global monthly mean SF₆ at the marine surface sites (NOAA GML) · U.S. Government work, public domain; cite the NOAA GML trend data set · 10/25/26 Current · provisional
Radiative forcing of long-lived gases
3.59 W/m²
2025
relative to 1750 (AGGI)
 
Annual Greenhouse Gas Index and radiative forcing by gas (NOAA GML) · U.S. Government work, public domain; cite Hofmann et al. (2006) and the NOAA AGGI · 10/25/26 Current
AGGI index
1.559
2025
forcing relative to 1990
 
Annual Greenhouse Gas Index and radiative forcing by gas (NOAA GML) · U.S. Government work, public domain; cite Hofmann et al. (2006) and the NOAA AGGI · 10/25/26 Current
Annual increase of CH₄
4.8 ± 0.4 ppb/yr
2025
provisional value
 
Annual increase of global CH₄ (NOAA GML) · U.S. Government work, public domain; cite the NOAA GML trend data set · 10/25/26 Current · provisional
Annual increase of CO₂
2.06 ± 0.08 ppm/yr
2025
provisional value
 
Annual increase of global CO₂ (NOAA GML) · U.S. Government work, public domain; cite the NOAA GML trend data set · 10/25/26 Current · provisional
Radiative forcing of each gas since 1979 Annual Greenhouse Gas Index and radiative forcing by gas (NOAA GML) · U.S. Government work, public domain; cite Hofmann et al. (2006) and the NOAA AGGI · 10/25/26 Current
Show the data as a table
Radiative forcing (W/m²) relative to 1750, computed by NOAA from the measured mole fractions and the IPCC formulas. CO₂ provides about two thirds; CFCs, banned by the Montreal Protocol, have been declining since the early 2000s.
Global methane since 1983 Global monthly mean CH₄ at the marine surface sites (NOAA GML) · U.S. Government work, public domain; cite the NOAA GML trend data set · 10/25/26 Current · provisional
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Monthly mean of the marine sites of the NOAA network (ppb) and deseasonalised trend. The rise stalled around 2000–2006 then resumed, with records in 2020–2022.
Annual increase of global methane Annual increase of global CH₄ (NOAA GML) · U.S. Government work, public domain; cite the NOAA GML trend data set · 10/25/26 Current · provisional
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Year-on-year increase (ppb/yr) with its uncertainty; sources (tropical wetlands, agriculture, energy) and the sink (OH radical) explain its variations.
Global nitrous oxide since 2001 Global monthly mean N₂O at the marine surface sites (NOAA GML) · U.S. Government work, public domain; cite the NOAA GML trend data set · 10/25/26 Current · provisional
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Monthly mean (ppb) and trend; the rise, mostly from nitrogen fertilisers, is accelerating.
Global sulphur hexafluoride since 1997 Global monthly mean SF₆ at the marine surface sites (NOAA GML) · U.S. Government work, public domain; cite the NOAA GML trend data set · 10/25/26 Current · provisional
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SF₆ (ppt), an entirely artificial gas (electrical equipment) with a very high warming potential and a lifetime of several centuries.
Annual increase of global CO₂ Annual increase of global CO₂ (NOAA GML) · U.S. Government work, public domain; cite the NOAA GML trend data set · 10/25/26 Current · provisional
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Year-on-year increase (ppm/yr); El Niño years speed up the rise (weaker land sink), La Niña years slow it.
Method and sources

Global means computed by NOAA from the marine boundary-layer sites of its sampling network (flasks collected and analysed in Boulder), with an uncertainty and a deseasonalised trend (Thoning et al.). The latest months, without an uncertainty yet, are provisional. Annual increases: official NOAA values.

Radiative forcing: table of the Annual Greenhouse Gas Index (AGGI, Hofmann et al., 2006), converting the mole fractions of long-lived gases into W/m² relative to 1750; the index is 1 in 1990, the reference year of the Kyoto Protocol.

Reading these data
These means describe background air, far from sources: a city or a farming region has higher and more variable concentrations. The AGGI forcing counts neither ozone, nor aerosols, nor water vapour: it is not the total anthropogenic forcing.
SOURCES OF THIS PAGE
Global monthly mean CO₂ at the marine surface sites (NOAA GML)
Lan, X., Tans, P. and Thoning, K. W. (2023). Trends in globally-averaged CO2 determined from NOAA Global Monitoring Laboratory measurements. · doi:10.15138/9N0H-ZH07 · source page ↗
Licence : U.S. Government work, public domain; cite the NOAA GML trend data set · retrieved on Oct 25, 2026 · SHA-256 a132ef94e937…
Global monthly mean CH₄ at the marine surface sites (NOAA GML)
Thoning, K., Dlugokencky, E. and Lan, X. (2022). Trends in globally-averaged CH4, N2O, and SF6 determined from NOAA Global Monitoring Laboratory measurements. · doi:10.15138/P8XG-AA10 · source page ↗
Licence : U.S. Government work, public domain; cite the NOAA GML trend data set · retrieved on Oct 25, 2026 · SHA-256 b51e4a4e6527…
Global monthly mean N₂O at the marine surface sites (NOAA GML)
Thoning, K., Dlugokencky, E. and Lan, X. (2022). Trends in globally-averaged CH4, N2O, and SF6 determined from NOAA Global Monitoring Laboratory measurements. · doi:10.15138/P8XG-AA10 · source page ↗
Licence : U.S. Government work, public domain; cite the NOAA GML trend data set · retrieved on Oct 25, 2026 · SHA-256 0e26d0e65593…
Global monthly mean SF₆ at the marine surface sites (NOAA GML)
Thoning, K., Dlugokencky, E. and Lan, X. (2022). Trends in globally-averaged CH4, N2O, and SF6 determined from NOAA Global Monitoring Laboratory measurements. · doi:10.15138/P8XG-AA10 · source page ↗
Licence : U.S. Government work, public domain; cite the NOAA GML trend data set · retrieved on Oct 25, 2026 · SHA-256 e489c8a4a4f5…
Annual Greenhouse Gas Index and radiative forcing by gas (NOAA GML)
NOAA Annual Greenhouse Gas Index (AGGI), radiative forcing relative to 1750 of the long-lived greenhouse gases, from NOAA network measurements. Hofmann, D. J., et al. (2006). Tellus B, 58, 614–619. · doi:10.1111/j.1600-0889.2006.00201.x · source page ↗
Licence : U.S. Government work, public domain; cite Hofmann et al. (2006) and the NOAA AGGI · retrieved on Oct 25, 2026 · SHA-256 b409de733051…
Annual increase of global CH₄ (NOAA GML)
Thoning, K., Dlugokencky, E. and Lan, X. (2022). Trends in globally-averaged CH4, N2O, and SF6 determined from NOAA Global Monitoring Laboratory measurements. · doi:10.15138/P8XG-AA10 · source page ↗
Licence : U.S. Government work, public domain; cite the NOAA GML trend data set · retrieved on Oct 25, 2026 · SHA-256 0501e15f5ffe…
Annual increase of global CO₂ (NOAA GML)
Lan, X., Tans, P. and Thoning, K. W. (2023). Trends in globally-averaged CO2 determined from NOAA Global Monitoring Laboratory measurements. · doi:10.15138/9N0H-ZH07 · source page ↗
Licence : U.S. Government work, public domain; cite the NOAA GML trend data set · retrieved on Oct 25, 2026 · SHA-256 7436b8f62038…
Hofmann et al. (2006)
Hofmann, D. J., Butler, J. H., Dlugokencky, E. J., Elkins, J. W., Masarie, K., Montzka, S. A., & Tans, P. (2006). The role of carbon dioxide in climate forcing from 1979 to 2004: introduction of the Annual Greenhouse Gas Index. Tellus B, 58(5), 614–619. · doi:10.1111/j.1600-0889.2006.00201.x
Licence : Published literature; cited

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