Contents

 Global annual mean mole fractions

Download csv data files.

	CO2	CH4	N2O
Data (csv file)	Mole fraction, Uncertainty	Mole fraction, Uncertainty	Mole fraction, Uncertainty

Global annual mean mole fractions of major greenhouse gases (GHGs) from the WMO GAW global GHG observational network.
The averaging method is described in (1). Uncertainties (Unc.) represent 68% confidence levels (2, 3).

CO2 [ppm] CH4 [ppb] N2O [ppb] Mean Unc. Mean Unc. Mean Unc. 1984 344.5 0.1 1656 2 303.9 0.1 1985 345.9 0.1 1668 2 304.5 0.1 1986 347.3 0.1 1680 2 305.3 0.1 1987 349.1 0.1 1693 2 305.9 0.1 1988 351.4 0.1 1704 2 306.7 0.1 1989 353.1 0.1 1715 2 307.6 0.1 1990 354.3 0.1 1725 2 308.6 0.1 1991 355.6 0.1 1736 2 309.4 0.1 1992 356.3 0.1 1745 2 309.9 0.1 1993 357.1 0.1 1748 2 310.1 0.1 1994 358.7 0.1 1753 2 310.7 0.1 1995 360.5 0.1 1760 2 311.4 0.1 1996 362.3 0.1 1763 2 312.0 0.1 1997 363.5 0.1 1766 2 312.9 0.1 1998 366.1 0.1 1776 2 313.8 0.1 1999 368.2 0.1 1783 2 314.6 0.1 2000 369.6 0.2 1784 2 315.7 0.1 2001 371.1 0.1 1783 2 316.4 0.1 2002 373.1 0.1 1784 2 317.1 0.1 2003 375.5 0.1 1788 2 317.8 0.1 2004 377.3 0.1 1788 2 318.4 0.1 2005 379.4 0.1 1787 2 319.1 0.1 2006 381.5 0.1 1787 2 320.0 0.1 2007 383.4 0.1 1793 2 320.7 0.1 2008 385.4 0.1 1800 2 321.7 0.1 2009 387.0 0.1 1805 2 322.5 0.1 2010 389.2 0.1 1810 2 323.4 0.1 2011 391.1 0.1 1816 2 324.4 0.1 2012 393.3 0.1 1821 2 325.3 0.1 2013 395.9 0.1 1827 2 326.2 0.1 2014 398.0 0.1 1836 2 327.3 0.1 2015 400.3 0.1 1846 2 328.3 0.1 2016 403.5 0.1 1854 2 329.1 0.1 2017 405.9 0.1 1862 2 329.9 0.1 2018 408.1 0.1 1871 2 331.1 0.1 2019 410.7 0.1 1879 2 332.0 0.1 2020 413.1 0.1 1890 2 333.2 0.1 2021 415.5 0.1 1907 2 334.4 0.1 2022 417.7 0.1 1923 2 335.8 0.1 2023 420.0 0.1 1934 2 336.9 0.1

CO2 CH4 N2O

 Global monthly mean mole fractions

Download csv data files.

	CO2	CH4	N2O
Data (csv file)	Mole fraction, Growth rate	Mole fraction, Growth rate	Mole fraction, Growth rate

	CO2	CH4	N2O
Mole fraction
Growth rate

WMO Greenhouse Gas Bulletin No.20, 2024.

 Zonally averaged monthly mean mole fractions

CO2	CH4	N2O

*These figures are not included in the Bulletin.

 Global analysis by WDCGG

Since 2006, WMO has published annual Greenhouse Gas Bulletins. These Bulletins report on the latest atmospheric abundances and rates of change for the main long-lived greenhouse gases (LLGHGs) — carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O) — and provide a summary of contributions from other greenhouse gases. Submission of original observation data from WMO GAW contributors worldwide supports WDCGG's global analysis of major greenhouse gases for the Greenhouse Gas Bulletin.

This page provides globally averaged data and associated graphs for CO₂, CH₄ and N₂O as used in the Bulletin. The information is updated annually based on newly submitted observation data.

WDCGG global analysis is conducted after careful screening of observation data exclusively from stations at which WMO-traceable scales are adopted. Details of the analysis are provided in GAW Report No.184⁽¹⁾.

The National Oceanic and Atmospheric Administration Global Monitoring Laboratory (NOAA/GML; the largest contributor of data to WDCGG) also calculates globally averaged mole fractions for major greenhouse gases⁽⁴⁾. The main difference in global analysis between NOAA/GML and WDCGG is the site selection process. NOAA/GML focuses on greenhouse gas data from the marine boundary layer (MBL) to represent the background atmosphere, while WDCGG also uses data from inland stations⁽⁵⁾ after stringent evaluation of their representativeness and traceability to WMO GAW standard scales.

Due to this difference, WDCGG globally averaged mole fractions for CO₂ are around 0.4 ppm greater than those from NOAA/GML⁽¹⁾. However, CO₂ trends and interannual variability are similar with both approaches.

 Information about citation

Figures and data in this page can be freely used with a citation, for instance:
"WMO Greenhouse Gas Bulletin, No.20, 2024."

 List of contributors

The global analyses can be impossible without the data contributors who conduct accurate measurements and submit the precious data to the WDCGG. The following table contains the contributors of the data actually used in the global analyses after screening process. For more information on stations, see the list of contributors and stations.

Organization	Acronym	Country/Territory
Advanced Global Atmospheric Gases Experiment Science Team(AGAGE)	AGAGE	Multinational
Agency on Hydrometeorology under Ministry of Emergency Situations of the Kyrgyz Republic	Kyrgyzhydromet	Kyrgyzstan
Atmospheric Chemistry Research Group School of Chemistry University of Bristol	UNIVBRIS	United Kingdom of Great Britain and Northern Ireland
Center for Environmental Science in Saitama	SAIPF	Japan
China Meteorological Administration	CMA	China
Commonwealth Scientific and Industrial Research Organisation	CSIRO	Australia
Direccion Meteorologica de Chile	DMC	Chile
Direcion Nacional del Antartico- Istituto Antartico Argentino, Buenos Aires, Argentina	IAA	Argentina
Environment and Climate Change Canada	ECCC	Canada
Federal Environment Agency Austria	UBAA	Austria
Finnish Meteorological Institute	FMI	Finland
German Environment Agency	UBAG	Germany
German Meteorological Service	DWD	Germany
Global Monitoring Laboratory, NOAA	NOAA	United States of America
Hungarian Meteorological Service	HMS	Hungary
Italian Air Force Mountain Centre	IAFMS	Italy
Italian National Agency for New Technologies, Energy and Sustainable Economic Development	ENEA	Italy
Japan Meteorological Agency	JMA	Japan
Kenya Meteorological Department	KMD	Kenya
Korea Meteorological Administration	KMA	Republic of Korea
Laboratoire des Sciences du Climat et de l'Environnement	LSCE	France
Meteorological Research Institute	MRI	Japan
National Institute for Environmental Studies	NIES	Japan
National Institute of Environmental Research	GERC	Republic of Korea
National Institute of Meteorological Research, KMA	METRI	Republic of Korea
National Institute of Water & Atmospheric Research Ltd.	NIWA	New Zealand
National Physical Laboratory	NPL	United Kingdom of Great Britain and Northern Ireland
National Research Council, Institute of Atmospheric Sciences and Climate	ISAC	Italy
Norwegian Institute for Air Research	NILU	Norway
Physics Institute, Climate and Environmental Physics, University of Bern	KUP	Switzerland
Ricerca sul Sistema Energetico - RSE S.p.A.	RSE	Italy
South African Weather Service	SAWS	South Africa
State Meteorological Agency of Spain	AEMET	Spain
Swiss Federal Laboratories for Materials Science and Technology	Empa	Switzerland
Tohoku University	TU	Japan
University of Exeter	UoE	United Kingdom of Great Britain and Northern Ireland
University of Urbino, Dep. of Pure and Applied Sciences (DISPEA)	UNIURB	Italy
University of York	UYRK	United Kingdom of Great Britain and Northern Ireland
Viet Nam Meteorological and Hydrological Administration	VNMHA	Viet Nam
Voeikov Main Geophysical Observatory	MGO	Russian Federation

References:

	(1)	Tsutsumi, Y., K. Mori, T. Hirahara, M. Ikegami, and T. J. Conway, 2009, Technical Report of Global Analysis Method for Major Greenhouse Gases by the World Data Center for Greenhouse Gases, GAW Report No.184
	(2)	Conway, T. J., P. P. Tans, L. S. Waterman, K. W. Thoning, D. R. Kitzis, K. A. Masarie, and N. Zhang, 1994, Evidence for interannual variability of the carbon cycle from the NOAA/CMDL global air sampling network, J. Geophys. Res., vol.99, 22831-22855, https://doi.org/10.1029/94JD01951.
	(3)	Technical Note on uncertainty for the GHG global mean mole fractions by the WDCGG
	(4)	Trends in Atmospheric Carbon Dioxide by NOAA/GML https://gml.noaa.gov/ccgg/trends/global.html
	(5)	Station distribution map for the WDCGG global analysis