2020 was one of the three hottest years since temperatures have been monitored regularly. And the last six have been the six hottest on record. Greenhouse gas concentrations in the atmosphere have continued to rise and are at historic highs dating back at least to 2003. Over the past five years, the global mean temperature has been 1.2 degrees Celsius above the 1850–1900 period. The picture presented in the new report from the Copernicus European climate change service, entitled European State of the Climate 2020, is simply alarming.

In Europe, temperatures during winter 2020 were 3.4 degrees above average

The study, published on Thursday 22 April, explains that in Europe 2020 saw the warmest winter and autumn on record. During the cold season, temperatures were as much as 3.4 degrees Celsius higher than average, particularly across north-eastern Europe. This had an enormous impact on snow cover and, for example, on the sea-ice extent in the Laptev Sea, which between June and November was at its lowest ever recorded.

2020 will be remembered for record heat in Siberia, wildfires and Storm Alex

"In particular in Siberia – explained Freja Vamborg, of the European Centre for Medium-Range Weather Forecasts (Ecmwf) – temperatures recorded extraordinarily high figures: 6 degrees Celsius above average." Snowfall was also low, and wildfires broke records in both number and extent.

The Copernicus report also highlights how "numerous heatwaves were recorded during the summer, affecting several regions, although they were not as intense as those of previous years." 2020 was also marked by the passage of Storm Alex, which brought record rainfall to western Europe, "causing flooding in parts of Spain, France, the United Kingdom and the southern Alps," added Vamborg. Nevertheless, the number of sunny days recorded was the highest since 1983.

CO2 concentrations up 0.6% globally

With regard specifically to the Arctic, 2020 proved to be the warmest year on record, and by a wide margin. During the month of March, a particularly strong polar vortex also caused a record reduction in ozone in the atmosphere of the northern hemisphere. At the same time, the Ecmwf climatologist also explained that "in 2020, CO2 concentrations increased by 0.6 per cent, while those of methane rose by 0.8 per cent."

Vincent-Henri Peuch, director of the Copernicus Atmosphere Monitoring Service Cams, commented in this regard that "it will inevitably be necessary to revise the targets at the global level in terms of reducing greenhouse gas emissions."

"Copernicus service data must be used to act"

More broadly, Carlo Buontempo, director of the Copernicus C3S climate change service, commented at the presentation of the report, explaining that it represents "a comprehensive analysis of the main climate events in Europe. It considers multiple indicators and places them in a global context. It is essential to monitor every interconnected variable in order to keep watch over our climate system and understand its changes." This with a view to taking the consequent decisions: "Now more than ever, we need to use the information at our disposal to act, mitigating and adapting to climate change. We must accelerate our efforts to reduce risks in the future."

In 2019, the United Nations Environment Programme (Unep) had stated that, in order to achieve a limitation of the global mean temperature, by 2100, to 1.5 degrees above the pre-industrial period, it is necessary to reduce emissions by 7.6 per cent. And to do so every year, until 2030.