European State Of The Climate Report: 2021 Warmest Summer Ever

The Copernicus Climate Change Service today releases its annual European State of the Climate report, examining climate variability of 2021 in Europe and globally. The report also provides the longer-term context and trends in key climate change indicators.

Europe experienced its warmest summer on record in 2021, accompanied by severe floods in western Europe and dry conditions in the Mediterranean.

Global

• The last seven years were the warmest on record, with 2021 ranking between 5^th and 7^th warmest^[1]
• Greenhouse gas concentrations of carbon dioxide (CO₂), and particularly methane (CH₄), continued to rise during 2021, by around 2.3 ppm and 16.5 ppb, respectively

Europe

• Europe experienced its warmest summer on record, at 1.0°C above the 1991-2020 average^[2]
• Record rainfall contributed to severe flooding in western Europe
• Annual sea surface temperatures (SST) in large areas of the Baltic and eastern Mediterranean Seas were the highest since at least 1993. In June and July, SSTs in parts of the Baltic were more than 5°C above average.

Summer extremes in the Mediterranean region

• The Mediterranean region experienced an intense and prolonged heatwave in July-August
• Temperature records were broken in Italy and Spain, the former being a provisional maximum daily temperature record for Europe
• Several countries, including Turkey, Greece and Italy saw intense wildfires

Low wind speeds in western Europe

• Some countries saw some of the lowest annual wind speeds since at least 1979
• Lower than average wind speeds led to reduced potential for wind energy production in some western European countries

Flooding in western Europe

• Record rainfall on 14^th July 2021 over Belgium and western Germany
• Record river discharge in parts of the Meuse and Rhine catchments
• Record-breaking rainfall and saturated soils contributed to the exceptional flooding event

Key findings for the Arctic

• Carbon emissions from Arctic wildfires were the 4^th highest since records began in 2003, mostly from eastern Siberia
• Sea ice minimum reached its 12^th lowest extent since satellite records began in 1979
• The Greenland Sea saw its lowest minimum sea ice extent on record

European State Of The Climate report released

The Copernicus Climate Change Service (C3S), implemented by the European Centre for Medium-Range Weather Forecasts on behalf of the European Commission, today releases its European State of the Climate 2021 (ESOTC 2021). Produced every spring, 2022 marks the 5^th edition of the report, released on Earth Day. The in-depth report provides key indicators, insights and a comprehensive analysis of climate conditions in 2021 with a focus on Europe and the Arctic.

The 2021 global perspective includes increasing surface air and sea surface temperatures, sea level rise and glacier mass loss, while Europe saw a year of extremes including heatwaves, record sea surface temperatures, wildfires, flooding, and unusually low wind speeds in some regions.

Globally – in brief

The report confirms that globally, the last seven years were the warmest on record with 2021 being among the cooler of these, and that average global sea surface temperature (SST) for 2021 was the 6^th or 7^th warmest since 1850. However, there is a clear increase globally both over land and sea compared to pre-industrial levels, with global surface air temperatures having increased between 1.1 and 1.2°C. La Niña conditions at the beginning and end of the year meant that 2021 SSTs were cooler globally than in recent years, which also impacted surface air temperatures over land and ocean.  Global sea level continued to rise during 2021; the total increase since 1993 is around 9cm. Latest consolidated data, up until the end of 2020, show that the Greenland and Antarctic ice sheets continued to lose mass.

Global average near-surface temperature for centred running 60-month periods, relative to the 1991–2020 average (left-hand axis) and as an increase above the 1850–1900 level (right-hand axis), according to six datasets. Data source: ERA5 (C3S/ECMWF), JRA-55 (JMA), GISTEMPv4 (NASA), HadCRUT5 (Met Office Hadley Centre), NOAAGlobalTempv5 (NOAA) and Berkeley Earth. Credit: C3S/ECMWF.

Europe had a year of contrasts – while 2021 annual surface air temperatures were only around 0.2°C above the 1991-2020 average and outside the 10 warmest years on record, annual sea surface temperatures over parts of the Baltic and the Mediterranean were the highest since at least 1993.

The European spring was cooler than average, with some parts of Europe seeing an early onset of spring followed by a late frost event, impacting agriculture. In contrast, summer brought record temperatures, as well as severe and long-lasting heatwaves, and an exceptional flooding event. In June and July, sea surface temperatures were also unusually warm, with parts of the Baltic more than 5°C higher than average.

Summer (June–August)temperatureanomalies over land for Europe as a whole from 1950–2021, relative to the 1991–2020 reference period. Data source: ERA5, E-OBS. Credit: C3S/ECMWF/KNMI.

Annual wind speeds across parts of western and central Europe were among the lowest since at least 1979 – Reanalysis data aids in assessing the potential impact of low wind speeds on renewable energy production.

Lower than average wind speeds in parts of western and central Europe led to a reduction in the estimated potential for wind power generation. Countries with the most below average wind speeds include Ireland, the United Kingdom, Czechia, Denmark and Germany. Some areas of which experienced the lowest or second-lowest annual wind speeds since at least 1979. In contrast, parts of southeastern Europe saw much higher-than-average annual wind speeds.

Rankings of annual average 100 m wind speeds in 2021 from lowest (dark blue) to highest (dark red) within the 43-year record which covers 1979 to 2021. Data source: ERA5. Credit: C3S/ECMWF.

A summer of high heat stress and devastating wildfires – The Mediterranean region was affected by a summer of extremes including an intense heatwave, drought, record temperatures, extreme heat stress and wildfires.

During the summer heatwave, many temperature records were broken, including a provisional national record for Spain at 47.0°C and a provisional European record of 48.8°C in Italy. In parts of Italy, Greece and Turkey, the heatwave lasted for two to three weeks. Additionally, the widespread dry conditions were conducive to numerous, devastating wildfires, particularly in Italy, Greece and Turkey. The total area burnt during July and August in the Mediterranean region exceeded 800,000 ha.

Flooding in western Europe – Severe flooding in July caused devastation in parts of Europe including Belgium, Germany, and some surrounding countries.

A slow-moving, low-pressure system travelled across Europe, drawing moist air from an unusually warm Baltic Sea. On 14July 2021, record rainfall amounts were observed in the affected region, and the resulting river discharge in parts of the Meuse and Rhine catchments was also estimated to be the highest in the record dating back to 1991. Saturated soils prior to event, alongside the record rainfall are contributory factors to the extreme nature of the event.

Arctic – the 4^th highest amount of carbon emissions from wildfires since 2003, mostly from eastern Siberia, though well below the record levels seen in 2020.

Compared to 2020, Arctic temperatures were less extreme, with large parts of Siberia being colder than average, especially in the early part of the year. Intense wildfires in subarctic Siberia led to smoke spreading across the Arctic region. Arctic sea ice extent remained below average throughout the year. However, during summer and autumn, it was well above the record-low values seen in previous years.

Time series of monthly mean Arctic sea ice extent anomalies for all September months from 1979 to 2021. The anomalies are expressed as a percentage of the September average for the 1991–2020 reference period. Data source: EUMETSAT OSI SAF Sea Ice Index v2.1. Credit: C3S/ECMWF/EUMETSAT.

Greenhouse gas concentrations continue to increase

In 2021, global concentrations of carbon dioxide (CO₂) and methane (CH₄) continued to increase. There was an especially large rise in atmospheric methane concentration. Estimates from satellite data show that concentrations of CO₂ have increased by around 2.3 ppm and CH₄ by around 16.5 ppb.

(Top) Monthly global CO₂ concentrations from satellites, for 2003–2021. The numbers in red indicate annual XCO₂ averages. (Bottom) Annual mean XCO₂ growth rates derived from concentration data shown in the top panel. The numbers in red correspond to the growth rate in ppm/year, including an uncertainty estimate in brackets. The X indicates an average over the whole atmospheric column. Data source: C3S/Obs4MIPs (v4.3) consolidated (2003–mid-2020) and CAMS preliminary near real-time data (mid-2020–2021) records. Credit: C3S/CAMS/ECMWF/University of Bremen/SRON.

2021 findings underline long-term changes despite short-term variability – The long-term perspective shows that global and European temperatures have significantly increased since the pre-industrial era.

The European State of the Climate 2021 highlights long-term trends in key climate indicators. Some indicators show small year-to-year variability and thus most years will show a clear continuation of the trend, albeit with different magnitudes from year to year. For the latest year with available data, greenhouse gas concentrations and sea level continued to increase, while glaciers continued to lose mass, as did the Greenland and Antarctic ice sheets, albeit at a lower rate than other recent years, losing 397 ± 12 and 93 ± 157 Gigatonnes of ice respectively.

Average European temperature for centred running 60-month periods, relative to the 1991–2020 average (left-hand axis) and as an increase above the 1850–1900 level (right-hand axis), according to six different datasets. Data source: ERA5 (C3S/ECMWF), JRA-55 (JMA), GISTEMPv4 (NASA), HadCRUT5 (Met Office Hadley Centre), NOAAGlobalTempv5 (NOAA) and Berkeley Earth. Credit: C3S/ECMWF.

Other indicators, such as temperature and sea ice show larger year to year or even decadal variability, superimposed on these long-term trends. While 2021 did not rank as a record-warm year for either Europe or the globe, the European continent has warmed by around 2°C since the pre-industrial age and the globe between 1.1 and 1.2°C. SSTs demonstrate a clear long-term increase and globally 2021 was the 6^th or 7^th warmest since at least 1850. 2021 Arctic sea ice extent ranked 12^th lowest at its annual minimum in September.

Carlo Buontempo, Director of the Copernicus Climate Change Service (C3S), comments: “2021 was a year of extremes including the hottest summer in Europe, heatwaves in the Mediterranean, flooding and wind droughts in western Europe, showing that the understanding of weather and climate extremes is becoming increasingly relevant for key societal sectors. Accurate climate information is more important than ever before to help us make informed decisions.”

Mauro Facchini, Head of Earth Observation at the Directorate General for Defence Industry and Space for the European Commission, comments: “The EU’s Copernicus Climate Change Service has given us key climate insights for Europe and the world. Such comprehensive, free climate data is essential to achieve European climate ambitions for the Green Deal and Net Zero. Scientific experts like the IPCC have warned that we are running out of time to limit global warming to 1.5°C. This report stresses the urgent necessity to act as climate related extreme events are already occurring in Europe.”

The European State of the Climate 2021 report is compiled by C3S from a range of data sources from satellite to in-situ, with contributions from international climate science experts which includes Copernicus partners and national meteorological bodies.

Freja Vamborg, Senior Scientist at the Copernicus Climate Change Service, and Lead Author of the report, comments: “Now in its 5^th edition, the report highlights how the data we collect and process at C3S can be transformed into highly accurate and clear information to make collective and individual decisions. Collating the report is the result of enormous collaborations across all the Copernicus services, our partners and numerous climate and weather experts across the international community, including national meteorological and hydrological services, universities, research institutions and private entities.”

The Copernicus Climate Change Service will host a virtual media briefing for the European State of the Climate 2021 report on Thursday April 21st at 11.30 am CEST.  The conference will last for approximately 1.5 hours and will include a short presentation by the Lead Author, Dr. Freja Vamborg, followed by a Q&A session for journalists. The conference will be opened by Mauro Facchini, Head of Earth Observation at the Directorate General for Defence Industry and Space, European Commission.

^[1] 2021 ranks between the 5^th and 7^th warmest year depending on the dataset considered.

^[2] Unless otherwise stated, average throughout the document refers to the average of the 1991-2020 reference period.

Read more about the report in the online article:

https://climate.copernicus.eu/2021-european-state-climate-report-now-available-pr