The Golden Gate Bridge in San Francisco, in September 2020, as California was in the grip of large-scale fires. HAROLD POSTIC / AFP
2020 joined 2016 as one of the hottest years on record in the world according to the European Copernicus Climate Change Service (C3S). The year 2020 ended 1.25 ° C above the pre-industrial period, just like 2016.
The final data concerning the temperatures of 2020 will be stopped Thursday, January 14 by the World Meteorological Organization (WMO), which compiles five datasets, that of Copernicus, but also those of NASA, the United States Agency for Ocean and Atmospheric Observation (NOAA), the British meteorological services and the Japanese meteorological service. The WMO had already announced at the end of December that 2020 would rank in the three hottest years.
2.2 ° C above the pre-industrial period in Europe
While 2016 was marked by a strong episode of the natural oceanic phenomenon El Niño, which causes an overall rise in temperatures, 2020 saw the effects of a climate phenomenon with opposite trends called La Niña.
“It’s pretty clear that in the absence of the impacts of El Niño and La Niña on temperature year over year, 2020 would be the hottest year on record.”, assured Zeke Hausfather, climatologist at the Breakthrough Institute, noting that the world has gained 0.2 ° C per decade since the 1970s.
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In Europe, marked by an exceptional heat wave, the year 2020 was largely the hottest, 0.4 ° C above 2019, and 1.6 ° C above the reference period 1981-2010 , more than 2.2 ° C above the pre-industrial period.
This warming is already exceeding the objectives of the Paris Agreement. But these goals are for the entire planet and it is known that the lands are warming faster than the oceans and that some regions are warming much faster, such as the Arctic, where temperatures in 2020 were 6 ° C above the reference mean.
Far from the trajectory of the Paris agreement
In this same arctic region, particularly in Siberia, the year was also marked by a season of forest fires. “Exceptionally dynamic”, releasing 244 megatonnes of carbon dioxide (CO2), is “More than a third more than the 2019 record”.
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Beyond a single isolated year, the 2015-2020 period is the hottest on record and the last decade (2011-2020) is also the hottest since the start of the industrial era. C3S director Carlo Buontempo insists:
“It’s no surprise that the past decade has been the hottest on record, and it reminds us once again of the urgency to ambitiously cut emissions in order to prevent adverse climate effects in the future. “
These harmful effects are already being felt across the planet, from melting sea ice to exceptional heat waves, through unprecedented precipitation or the last record hurricane season in the Caribbean.
And the worst is yet to come. The planet has gained at least 1.1 ° C compared to the pre-industrial era, with already its share of climatic catastrophes. But despite the objectives of the Paris agreement to keep global warming well below + 2 ° C, if possible + 1.5 ° C, the states’ current commitments to reduce greenhouse gases are still far from this. path.
Stop CO emissions2
Despite the measures taken against the Covid-19 pandemic and the slowdown in the economy which have led to a drop in CO emissions2 in 2020 (- 7% according to the Global Carbon Project), the concentration of CO2 in the atmosphere continued to rise, according to satellite data from Copernicus. Reaching “An unprecedented maximum” of 413 ppm (parts per million) in May 2020.
“If carbon dioxide concentrations increased slightly less in 2020 than in 2019, there is no need to rest on our laurels, warned Vincent-Henri Peuch, boss of the Copernicus atmosphere monitoring service. Until net global emissions are reduced to zero, CO2 will continue to accumulate in the atmosphere and cause further climate change. “
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