Newsflash

Reading, 07 January 2019

Air temperature at a height of two metres for 2018, shown relative to its 1981–2010 average.

Source: Copernicus Climate Change Service, ECMWF

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Data released by the Copernicus Climate Change Service (C3S) show that 2018 was the fourth in a series of exceptionally warm years and together with the Copernicus Atmosphere Monitoring Service (CAMS), C3S reports that atmospheric CO 2 concentrations have continued to rise.

C3S and CAMS are services of the European Union’s Earth observation programme Copernicus and are implemented by ECMWF. Their data provide the first complete, global picture of 2018 temperatures and CO 2 levels. The results are in line with previous projections from WMO and the Global Carbon Project (GCP) for 2018. The temperature dataset of the Copernicus Climate Change Service shows that the global average surface air temperature was 14.7°C, 0.2°C lower than in 2016, the warmest year on record. The data reveal that:

The last four years have been the warmest four on record, with 2018 being the fourth warmest, not far short of the temperature of the third warmest year 2015.

2018 was more than 0.4°C warmer than the 1981-2010 average.

The average temperature of the last 5 years was 1.1°C higher than the pre-industrial average (as defined by the IPCC).

Europe saw annual temperatures less than 0.1°C below those of the two warmest years on record, 2014 and 2015.

Furthermore, according to satellite measurements of global atmospheric CO 2 concentrations:

CO 2 continued to rise in 2018 and increased by 2.5 +/- 0.8 ppm/year.

“The Copernicus Climate Change Service provides quality assured data of climate indicators like surface temperature, sea-ice cover and hydrological variables like precipitation”, says Jean-Noël Thépaut, Head of the Copernicus Climate Change Service (C3S). “In 2018, we have again seen a very warm year, the fourth warmest on record. Dramatic climatic events like the warm and dry summer in large parts of Europe or the increasing temperature around the Arctic regions are alarming signs to all of us. Only by combining our efforts, can we make a difference and preserve our planet for future generations.”

C3S provides an early picture of 2018 global temperatures

The C3S temperature data for 2018 is the first complete set to be published including annual anomalies and globally averaged fields. C3S can provide the global picture so rapidly because it is an operational programme, processing millions of land, marine, airborne and satellite observations daily. A mathematical model is used to bring all these observations together, in a similar way to what is done in weather forecasting. The benefit to users of the data is that they have an accurate estimate of temperatures at any time or place they choose – even in sparsely-observed areas like the polar regions.

The Copernicus C3S data show that 2018 surface temperatures were more than 0.4°C higher than the long-term average recorded over the period 1981-2010. The most pronounced warming compared to the long-term average occurred in the Arctic, in particular in and north of the Bering Strait between USA and Russia and around the Svalbard archipelago. Most land areas were warmer than average, especially Europe, the Middle East and the western USA. In contrast, the northeast of north America and some central areas of Russia and central Asia experienced below average annual temperatures.

Apart from a relatively cold February and March, Europe saw above average temperatures during all months of the year. Starting at the end of spring and continuing well into autumn, and in some places even winter, northern and central Europe experienced weather conditions that were persistently warmer and drier than average.

Running 60-month averages of global air temperature at a height of two metres (left-hand axis) and estimated change since the pre-industrial period (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).

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A reliable view from combined datasets

The method used for the C3S temperature dataset complements that of other datasets which use ground-based measurements over a long-term period. The datasets mainly differ in how they represent the polar regions and temperatures over the oceans. Combining datasets provides the most complete picture possible. This analysis shows that global surface air temperature has increased by an average of 0.1°C every five to six years since the mid-1970s and that the last five years were approximately 1.1°C above the temperatures of the pre-industrial era.

The WMO will combine the different types of temperature datasets for its statement on the State of the Climate in 2018. This statement will be released in March 2019 and is expected to confirm the C3S findings.

CO 2 concentrations continue to increase

The analysis of satellite data indicates that carbon dioxide concentrations have continued to rise in recent years, including in 2018. The dataset is a combination of two datasets that were generated for C3S and CAMS.

While the WMO and the Global Carbon Project (GCP) reports are based on surface observations, this CO 2 dataset provided by Copernicus is based on satellite observations. The quantity monitored is the average concentration of CO 2 for the entire air column above a given location, called XCO 2 . Because higher atmospheric layers, such as the stratosphere, typically contain less CO 2 , the XCO 2 values are usually somewhat lower than CO 2 concentrations measured near the Earth’s surface. This is why satellite XCO 2 values are similar, but not exactly identical to estimates based on surface observations.

The estimated annual mean XCO 2 growth rate for 2018 is 2.5 +/- 0.8 ppm/year. This is larger than the growth rate in 2017, which was 2.1 +/- 0.5 ppm/year, but less than the 3.0 +/- 0.4 ppm/year in 2015. 2015 was a year with a strong El Niño climate event, which resulted in a weaker than normal uptake of atmospheric CO 2 by the terrestrial vegetation, and large CO 2 emissions from wildfires, for example in Indonesia.

Monthly global CO2 concentrations from satellites, column-averaged CO2 (XCO2), for 2003-2018. The listed numerical values in red indicate annual averages. Based on the C3S/Obs4MIPs(v3.1) consolidated (2003-2017) and CAMS preliminary near-real time data (2018) records. Source: University of Bremen for Copernicus Climate Change (C3S) and Atmosphere Monitoring (CAMS) Services implemented by ECMWF

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Paris review: IPCC highlights urgency

In accordance with the 2015 Paris Agreement on climate change, the participating countries plan to undertake a review of the status quo every five years. The recent special report ‘Global warming of 1.5°C’ by the Intergovernmental Panel on Climate Change (IPCC) further underlines the urgency of implementing effective measures to mitigate climate change. The Copernicus Climate Change Service and Copernicus Atmosphere Monitoring Service make a significant contribution to these efforts by providing timely and accurate information about the current global temperature and CO 2 status.

Monthly climate updates

In addition to the annual temperature values, C3S routinely publishes climate bulletins at the beginning of each month, reporting on changes observed in global surface air temperature, sea ice cover and hydrological variables. The latest climate update for the month of December is now available.

December 2018 surface air temperature

Globally, temperatures were just under 0.5°C above the average December for 1981-2010

Canada, the Atlantic sector of the Arctic and northern Russia saw much above average temperatures

Large parts of southern Russia, central Asia and China saw much below average temperatures

Australia experienced exceptionally hot and dry conditions.

In Europe, temperatures were generally above average, but the southern Balkans and Greece saw below average temperatures

More information and high-resolution graphics can be downloaded here: https://climate.copernicus.eu/climate-bulletins

Notes for editors

About the data - Temperatures

The map and quoted data values are from ECMWF Copernicus Climate Change Service’s ERA-Interim dataset. The graph is based on ERA-Interim and four other datasets: JRA-55 produced by the Japan Meteorological Agency (JMA), GISTEMP produced by the US National Aeronautics and Space Administration (NASA), HadCRUT4 produced by the Met Office Hadley Centre in collaboration with the Climatic Research Unit of the University of East Anglia, and NOAAGlobalTemp produced by the US National Oceanic and Atmospheric Administration (NOAA). The ERA-Interim and JRA-55 datasets run to the end of 2018; the other datasets are currently available only to the end of November 2018. The data have been accessed and processed as described in a peer-reviewed publication (doi: 10.1002/qj.2949).

Each dataset shown in the graph is aligned to have the same average temperature for 1981–2010 as ERA-Interim. For JRA-55 this entails a temperature reduction of 0.1°C. The other datasets are originally defined only as values relative to reference periods. HadCRUT4 is an ensemble of 100 possible realisations. The median and range of the ensemble are plotted. The ensemble does not sample the uncertainty associated with limited geographical coverage, which is substantial for the earliest decades.

1981–2010 is the latest 30-year reference period defined by the WMO for calculating climatological averages. It is the first such period for which satellite observations of key variables including sea-surface temperature and sea-ice cover are available to support globally complete meteorological reanalyses such as ERA-Interim.

The climatological average temperature for the pre-industrial period is taken to be 0.63°C lower than the average for 1981–2010. This follows what is suggested in the IPCC ‘Global warming of 1.5°C’ report, which estimates the increase from the pre-industrial (defined as 1850-1900) to the 20-year period 1986-2005 to be “0.63°C (±0.06°C 5–95% range based on observational uncertainties alone)”. The annual mean temperature difference between the periods 1981-2010 and 1986-2005 is non-significant for all datasets presented here (-0.009°C to +0.004°C).

About the data - Carbon dioxide concentrations

We present a timeseries of monthly global averages of atmospheric carbon dioxide (CO 2 ) derived from satellite sensors. Satellite-derived CO 2 concentrations are representative of the column-averaged CO 2 mixing ratio, also denoted XCO 2 . The annual averages given in the graph are derived by computing the average of the monthly values.

The data for 2003-2017 is the consolidated product of “C3S XCO 2 data derived from satellite sensors”, produced by the Copernicus Climate Change Service. The high quality C3S climate data record has been generated by merging an ensemble of individual satellite datasets from the satellite instruments SCIAMACHY/ENVISAT and TANSO-FTS/GOSAT, using products generated by C3S and ESA GHG-CCI in Europe, NASA in the USA and NIES in Japan. This merged product, which is available in Obs4MIPs format (see Obs4MIPs website https://esgf-node.llnl.gov/projects/obs4mips/), is extended each year by one additional year and year 2018 data will be available end of 2019. For details see Buchwitz et al., 2018 (https://www.atmos-chem-phys.net/18/17355/2018/ and/or https://doi.org/10.1007/s42423-018-0004-6).

The data for 2018 is the near-real time preliminary product of “CAMS XCO 2 data derived from satellite sensors”, produced by the Copernicus Atmosphere Monitoring Service. This data product has been generated from TANSO-FTS/GOSAT. For details see Heymann et al., 2015 (https://www.atmos-meas-tech.net/8/2961/2015/amt-8-2961-2015.html).

The annual mean XCO 2 growth rates have been computed using the method of Buchwitz et al., 2018 (https://www.atmos-chem-phys.net/18/17355/2018/).

About Copernicus

Copernicus is the European Union’s flagship Earth observation programme. It delivers freely accessible operational data and information services which provide users with reliable and up-to-date information related to environmental issues.

Copernicus Climate Change Service (C3S) is implemented by the European Centre for Medium-Range Weather Forecasts (ECMWF) on behalf of the European Union. ECMWF also implements the Copernicus Atmosphere Monitoring Service (CAMS). ECMWF is an independent intergovernmental organisation, producing and disseminating numerical weather predictions to its 34 Member and Co-operating States.

More information on Copernicus: www.copernicus.eu

The Copernicus Climate Change Service website can be found at https://climate.copernicus.eu

The Copernicus Atmosphere Monitoring Service website can be found at http://atmosphere.copernicus.eu

The ECMWF website can be found at https://www.ecmwf.int/