The past seven years have been the hottest ever recorded globally, according to Copernicus Climate Change Service (C3S), the European Union's climate monitoring service. In its latest annual assessment, the agency confirmed that 2021 had joined the unbroken warm streak since 2015.

C3S researchers had previously reported that 2020 was effectively tied for the warmest year on record — just behind 2016, which took first place. Now 2021 ranks fifth, slightly ahead of 2015 and 2018. Preliminary analysis of satellite measurements confirm that atmospheric greenhouse gas concentrations continued to rise during 2021, with carbon dioxide levels reaching an annual global column-averaged record of approximately 414 ppm, and methane concentrations posting an annual record of approximately 1876 ppb. Carbon emissions from wildfires worldwide amounted overall to 1850 megatons.

"Carbon dioxide and methane concentrations are continuing to increase year on year and without signs of slowing down," said Vincent-Henri Peuch, director of the Copernicus Atmosphere Monitoring Service. "Only with determined efforts backed up by observational evidence can we make a real difference in our fight against the climate catastrophe."

In 2021, the annual average temperature was 0.3° C above the temperature of the 1991 to 2020 reference period, and 1.1° C to 1.2° C above the pre-industrial level of 1850 to 1900. The highest above-average temperatures affected a region encompassing the west coast of the U.S. and Canada to northeastern Canada and Greenland, and large swaths of central and northern Africa and the Middle East.