2021 Was Earth’s Fifth Hottest Year, Scientists Say

2021 was Earth’s fifth-hottest year on record, mar­gin­ally warmer than 2015 and 2018, accord­ing to the European Union’s Copernicus cli­mate change ser­vice (C3S).

Despite tem­per­a­tures remain­ing rel­a­tively low through the first five months of the year, the globe expe­ri­enced unusu­ally warm weather with soar­ing tem­per­a­tures from June until October, lead­ing to an annual aver­age tem­per­a­ture of 0.3 °C above the 1991 to 2020 ref­er­ence period and 1.2 °C above the pre-indus­trial lev­els of 1850 to 1900, the Copernicus sci­en­tists said.

Europe, in par­tic­u­lar, suf­fered its hottest sum­mer ever in 2021. The con­ti­nent expe­ri­enced a record-break­ing tem­per­a­ture of 48.8°C in Sicily (pend­ing offi­cial con­fir­ma­tion), severe floods that swept sev­eral cen­tral European coun­tries and hun­dreds of wild­fires that dev­as­tated thou­sands of hectares of forests and agri­cul­tural land in the Mediterranean basin, mainly impact­ing Italy, Greece and Turkey.

The last seven years were the warmest on record, with 2021 5^th but with a small mar­gin to 2015 and 2018. See in the video which regions had the largest geo­graph­i­cal anom­alies for the year. #CopernicusClimate#C3Spic.twitter.com/1sbG5cLdVg

— Copernicus ECMWF (@CopernicusECMWF) January 10, 2022

Elsewhere, China announced that the past year was the country’s hottest on record, while the west of the United States and Canada suf­fered an abnor­mal heat­wave in June and July with tem­per­a­tures exceed­ing pre­vi­ous record highs by 5 °C.

“These events are a stark reminder of the need to change our ways, take deci­sive and effec­tive steps toward a sus­tain­able soci­ety and work towards reduc­ing net car­bon emis­sions,” Carlo Buontempo, the CS3 direc­tor, said.

According to the Copernicus rank­ing, the planet’s two hottest years on record were 2016 and 2020. Furthermore, the last seven years have been the warmest ​“by a clear mar­gin” since records began, con­firm­ing the upward curve of global tem­per­a­ture rises.

“The 2021 analy­sis, show­ing that glob­ally the warmest years by far were recorded in the last seven years, is a reminder of the con­tin­ued increase in global tem­per­a­tures and the urgent neces­sity to act,” Mauro Facchini, head of Earth obser­va­tion for the European Commission, said.

Greenhouse gas emis­sions also broke new records in 2021, with methane con­tin­u­ing to increase ​“very sub­stan­tially” and car­bon diox­ide emis­sions reach­ing new highs with 414 ppm (parts per mil­lion) per year, up by 2.4 ppm from 2020.

The high­est growth rates of CO2 emis­sions, how­ever, were observed in 2015 and 2016 (by 3.0 ppm and 2.9 ppm, respec­tively) and were asso­ci­ated with the El Niño cli­matic phe­nom­e­non.

The steep rise in atmos­pheric methane lev­els has always puz­zled sci­en­tists. This poten­tially harm­ful green­house gas can emanate from many sources, includ­ing the nat­ural processes of wet­lands, live­stock farm­ing and fos­sil fuel exploita­tion, mak­ing it hard to pin­point the exact rea­sons for the surge in emis­sions.

“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. ​“These green­house gases are the main dri­vers of cli­mate change.”

The find­ings of the Copernicus cli­mate change ser­vice are expected to be ver­i­fied by atmos­pheric data released by other mete­o­ro­log­i­cal ser­vices around the world in the com­ing weeks.

• Copermicus
• The Guardian