The seven years from 2015 to 2021 were “clearly” the hottest on record, confirming the advance of global warming with record concentrations of greenhouse gases, the European Copernicus observation service announced on Monday. Earth.
If 2021 was “only” the fifth year among the hottest on record, it suffered the devastating effects of climate change: exceptional and deadly heat waves in North America and southern Europe, devastating fires in Canada and Siberia. , a dramatic cold spell in the central United States, or extreme precipitation in China and Western Europe.
Despite a level pulled down by the La Niña weather phenomenon, 2021 still recorded according to Copernicus an average temperature higher by 1.1 ° C to 1.2 ° C compared to the pre-industrial era (1850-1900), a benchmark comparison to measure the warming caused by gas emissions greenhouse effect from human activity.
The objective of the 2015 Paris agreement, to contain warming “significantly” below 2 ° C, and if possible at 1.5 ° C, is therefore still dangerously close.
On an annual average, 2021 ranks slightly ahead of 2015 and 2018, with 2016 remaining the hottest.
And the last seven years “have been the hottest ever recorded, by a clear margin,” notes the European body.
“This is a stark reminder of the need for us to change, to take effective and decisive measures to move towards a sustainable society and to work to reduce carbon emissions,” underlined Carlo Buontempo, director of the department. climate change of Copernicus.
Because the agency measured for 2021 new record concentrations in the atmosphere of greenhouse gases produced by human activity and responsible for global warming.
CO2, by far the main cause of warming and which comes mainly from the combustion of fossil fuels and the production of cement, reached a record level of 414.3 ppm (parts per million), according to “preliminary” data from Copernicus.
“Nail in the coffin”
For 2020, despite the slowdown in activity due to the pandemic, the World Meteorological Organization (WMO, UN agency) had measured this concentration at 413.2 ppm, or 149% higher than the pre-industrial level.
Copernicus also tracks the release of methane, a greenhouse gas even more powerful than CO2 but which does not persist for a long time in the atmosphere, of which about 60% are of human origin (ruminant farming, rice cultivation, landfills, the rest coming from natural sources, such as peat bogs).
They too “continued to increase in 2021 […] reaching an unprecedented maximum average ”, according to the European agency, which stresses, however, that the origin of this increase is“ not fully understood ”.
[Il] becomes hard to say something new every time we see a new nail stuck in the planetary coffin
During the COP26 climate conference in November, around 100 countries joined an “initiative” aimed at reducing methane emissions by 30%. Objective which could, if it were met, make more realistic the slogan hammered out at the Glasgow conference of “keeping alive [l’objectif de] 1.5 degrees ”.
The emission reduction commitments made by the various countries, including those announced on the occasion of COP26, in fact leave the world on a warming trajectory of 2.7 ° C, a level described as “catastrophic” by the United States. ‘UN.
On the occasion of this COP, the WMO had already announced that the seven years since 2015 would probably be the hottest on record, warning that the global climate was therefore entering “unknown territory”.
“This is a new warning about what we are doing to our planet, [et] we desperately need real action to cut emissions, ”commented Sir Brian Hoskins, director of the Grantham Institute on Climate Change at Imperial College London on Monday. By emphasizing that “it becomes difficult to say something new every time we see a new nail stuck in the planetary coffin”.