Carbon Dioxide, Methane & Other Greenhouse Gases

The atmospheric abundance of carbon dioxide (CO2), the dominant human-produced greenhouse gas, has increased by about 50% since pre-industrial times due to the proliferation of fossil fuel combustion. Methane (CH4) is also a strong greenhouse gas; its atmospheric abundance has more than doubled since the pre-industrial era because of human activities. Other significant greenhouse gases include nitrous oxide (N2O), chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs) and sulphur hexafluoride (SF6).

Atmospheric CO₂ at Mauna Loa

Figure: Monthly mean atmospheric carbon dioxide at Mauna Loa Observatory, Hawaii

Source: Data are reported as a dry mole fraction defined as the number of molecules of CO2 divided by the number of molecules of dry air multiplied by one million (ppm).

ECV Products and Requirements

These products and requirements reflect the Implementation Plan 2022 (GCOS-244).

The requirements are found in the complete 2022 ECVs Requirements document as well: ECV Carbon Dioxide, Methane & Other Greenhouse Gases.

Products			CO₂mole fraction	CO₂ column average dry air mixing ratio		CH₄ mole fraction	CH₄column average dry air mixing ratio	N₂O mole fraction
	*()**	Unit	Values	Values	Unit	Values	Values	Values
Horizontal Resolution	G	km	100	1	km	100	0.3	100
	B		500	5		500	1	500
	T		2000	10		2000	10	2000
Vertical Resolution	G	km	0.1	-	km	0.1	-	0.1
	B		1	-		1	-	1
	T		3	-		3	-	3
Temporal Resolution	G	h	1	1	h	1	1	1
	B		24	12		24	12	24
	T		168	72		168	72	168
Timeliness	G	d	1	1	d	1	1	1
	B		30	7		30	7	30
	T		180	14		180	14	180
Required Measurement Uncertainty (2-sigma)	G	ppm	0.1	0.6	ppb	1	7	0.05
	B		0.2	1		2	10	0.1
	T		0.5	1.6		5	20	0.3
Stability	G	ppm/decade	0.1	0.1	ppb/decade	1	1	0.05
	B		0.1	0.2		1	2	0.05
	T		0.3	0.3		3	4	0.2

(*) Goal (G): an ideal requirement above which further improvements are not necessary. Breakthrough (B): an intermediate level between threshold and goal which, if achieved, would result in a significant improvement for the targeted application. The breakthrough value may also indicate the level at which specified uses within climate monitoring become possible. It may be appropriate to have different breakthrough values for different uses. Threshold (T): the minimum requirement to be met to ensure that data are useful

Data sources

This list provides sources for openly accessible data sets with worldwide coverage for which metadata is available. It is curated by the respective GCOS ECV Steward(s). The list does not claim to be complete. Anyone with a suitable dataset who wishes it to be added to this list should contact the abombelliwmo [dot] int (GCOS Secretariat).

In Situ:

NOAA Earth System Research Laboratory Global Monitoring Division Greenhouse Gas data
Network for the Detection of Atmospheric Composition Change (NDACC)
Total Carbon Column Observing Network (TCCON)
World Data Centre for Greenhouse Gases (WDCGG)

http://ds.data.jma.go.jp/gmd/wdcgg/

Reanalysis:

REANALYSES.ORG (Inventory for Reanalysis)
Monitoring Atmospheric Composition & Climate (MACC), European Centre for Medium-Range Weather Forecasts (ECMWF)
Copernicus Atmospheric Monitoring Service (CAMS), European Centre for Medium-Range Weather Forecasts (ECMWF)
Or you can access via this link : https://atmosphere.copernicus.eu/data

Satellite:

Satellite ECV Inventory by the CEOS/CGMS Working Group on Climate (WGClimate)

Domain:

Atmosphere

Subdomain:

Atmospheric Composition

Scientific Area:

Carbon cycle and other GHGs

ECV Steward:

Paolo Laj, Dale Hurst

Products:

CO2 Mole Fraction, CO2 Column Average Dry Air Mixing Ratio, CH4 Mole Fraction, CH4 Column Average Dry Air Mixing Ratio, N2O Mole Fraction