Global Climate Indicators

Global Climate Indicators


The Global Climate Indicators are a set of seven parameters that describe the changing climate without reducing climate change to only temperature. They comprise key information for the most relevant domains of climate change: temperature and energy, atmospheric composition, ocean and water as well as the cryosphere. 


Running 60-month averages of global air temperature at a height of two metres (left-hand axis) and estimated change from the beginning of the industrial era (right-hand axis) according to different datasets: ERA-Interim (Copernicus Climate Change Service, ECMWF); GISTEMP (NASA); HadCRUT4 (Met Office Hadley Centre), NOAAGlobalTemp (NOAA); and JRA-55 (JMA). Credit: Copernicus Climate Change Service/ECMWF

Ocean Heat

Global Ocean Heat Content Change (x 1022J) for the 0-700 metre layer: three-monthly means (red), and annual (black) and 5-year (blue) running means, from the US National Oceanic and Atmospheric Administration (NOAA) dataset. Credit: Prepared by WMO using data from the NOAA National Centers for Environmental Information. Source: WMO Statement on the state of the global climate in 2017.

Greenhouse Gases

The rate of increase of atmospheric carbon dioxide (CO2) over the past 70 years is nearly 100 times larger than that at the end of the last ice age. As far as direct and proxy observations can tell, such abrupt changes in the atmospheric levels of CO2 have never before been seen. The figure on the left shows the CO2 atmospheric content at the end of the last ice age, and the figure on the right shows recent atmospheric CO2 content [1]. The thin grey area on the left figure, which looks like a vertical line, corresponds to a similar period of 70 years as depicted on the right figure for modern times. Rapidly increasing atmospheric levels of CO2 and other greenhouse gases (GHGs) have the potential to initiate unpredictable changes in the climate system, because of strong positive feedbacks, leading to severe ecological and economic disruptions. The WMO Global Atmosphere Watch (GAW) Programme tracks the changing levels of GHGs and serves as an early warning system by detecting changes in these key atmospheric drivers of climate change. GAW publishes the latest trends and atmospheric burdens of GHG annually in the WMO-GAW Annual Greenhouse Gas Bulletins



Net global annual fluxes of CO, CH4 and N2O into the atmosphere are estimated by the Copernicus Atmosphere Monitoring Service flux atmospheric inversion systems. The units of the fluxes are in mass of Carbon for CO(PgC/year) and CH4 (TgC/year) and mass of Nitrogen for N2O (TgN/year). For CO2, the mass has also been converted to an equivalent atmospheric concentration in parts per million of number of molecules of COwith respect to molecules of dry air (ppm/year), assuming a conversion factor of 2.086 PgC/ppm. This conversion facilitates comparison with estimates of the atmospheric growth rate based on in situ observations (e.g. from Mauna Loa, Hawaii). Data source: CAMS greenhouse gas flux data, Credit: Copernicus Atmosphere Monitoring Service/ECMWF

Sea Level 

Daily global-mean mean sea level without annual and semi-annual signals for January 1993 to May 2017. The data has been adjusted for glacial isostatic adjustment. Data source: CMEMS Ocean Monitoring Indicator based on the C3S sea level product. Credit: Copernicus Climate Change Service/ECMWF/Copernicus Marine Environment Monitoring Service

Ocean Acidity

Trends in surface (< 50m) ocean carbonate chemistry calculated from observations obtained at the Hawaii Ocean timeseries (HOT) Program in the North Pacific over 1988-2015. The panel shows a decline seawater pH (black points, primary y-axis) and carbonate io concentration (green points, secondary y-axis). Credit: Ocean chemistry data were obtained from the Hawaii Ocean Timeseries Data Organization & Graphical System (HOT-DOGS). US National  Oceanic and Atmospheric Administration (NOAA), Jewett and Romanou, 2017. Source: WMO Statement on the state of the global climate in 2017.


Regionally averaged cumulative annual mass balance from 41 reference glaciers (with more than 30 years of ongoing observations) distributed globally. Values are shown relative to 1997 and are given in the unit ‘metre water equivalent (m w.e.)’. Data source: WGMS (2017, and earlier reports). Credit: Copernicus Climate Change Service/WGMS.

Sea Ice

Area of the Arctic (upper) and Antarctic (lower) covered by sea-ice, for the period January 1979 to December 2017, shown as monthly anomalies relative to 1981-2010. The darker coloured bars denote the December values. Data source: ERA-Interim. Credit: Copernicus Climate Change Service/ECMWF.

These Global Climate Indicators have been identified by scientists and communication specialists in a discursive process led by GCOS during workshops and scientific panel meetings and have been finally endorsed by WMO. They form the basis of the annual WMO Statement of the State of the Global Climate, which is submitted to the Conference of Parties of the United Nations Framework Convention on Climate Change (UNFCCC).

These seven headline indicators are complemented by a set of subsidiary indicators that provide additional information and allow a more detailed picture of the changes in the respective domain.

The Global Climate Indicators are a concept that is meant be used to tell stories about climate change in a way that can be understood by non-experts. It is important to note, that the Global Climate Indicators are not limited to specific datasets or certain storylines. A multitude of narratives, told in different ways and forms and fitted to the respective auditorium, will catch more peoples interest and finally form a more comprehensive picture of climate change.

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