Limiting global warming to 1.5 ° C is impossible without an immediate and massive reduction in greenhouse gas emissions, according to a new report on the subject released Thursday by the UN.

This annual report, “United in Science 2021”, drawn up by several UN agencies and associated scientists, is released a few weeks before COP26, a new global climate summit.

Climate change and its consequences continue to worsen, according to the document, and the temporary reduction in CO2 emissions into the atmosphere caused by the Covid-19 pandemic has not slowed the process.

The deadline for COP26

The 2015 Paris Agreement on climate change, signed at COP21, called for limiting global warming to less than 2 ° C above the pre-industrial level, and ideally 1.5 ° C. .

United Nations Secretary-General Antonio Guterres considers the report to be "an alarming diagnosis showing how far we have deviated from the course" leading to the objectives of the Paris Agreement.

“This year, fossil fuel emissions have rebounded, greenhouse gas concentrations continue to rise, and severe weather events caused by human activity have affected the health, lives and livelihoods of all. the continents ”, he writes in the report's foreword.

“Unless greenhouse gas emissions are reduced immediately and on a large scale, limiting warming to 1.5 ° C will be impossible, with catastrophic consequences for populations and the planet”.

The COP26, the next UN climate summit, will be held in Glasgow (Scotland, United Kingdom) from October 31 to November 12.

No pandemic effect

Greenhouse gas emissions peaked in 2019, before dropping 5.6% in 2020 due to restrictions and the economic slowdown linked to the pandemic.

But apart from air and maritime transport, average global emissions during the first seven months of 2021 have almost returned to their 2019 levels.

And according to the report, the concentrations of the main gases involved in warming - carbon dioxide, methane and nitrous oxide - continued to rise in 2020 and the first half of 2021.

Overall, the reduction in emissions in 2020 probably slowed the increase in greenhouse gas concentrations in the atmosphere, but the effect was "too small to be distinguished from natural variations" in these concentrations, the report points out. .

The global average temperature between 2017 and 2021 - including this year's average data up to June - is estimated to be between + 1.06 ° C and + 1.26 ° C compared to the pre-industrial period (1850-1900).

The world is at a "critical moment", and the report shows that "we really don't have any more time to waste," says Antonio Guterres.

Zero emission target

Canada set its all-time high for June with 49.6 ° C in Lytton, British Columbia. The heat wave in the Pacific Northwest was a very rare event, but it would have been "virtually impossible without human-induced climate change," the report said.

As for the severe flooding in July in Germany, the document estimates that human activity "increases the likelihood and intensity of such events".

The number of countries committing to a zero emissions goal is encouraging, according to the report, because today 63% of global emissions are affected by these goals, but by 2030 much larger actions are needed to be able to reach them.

"I hope that all these problems will be addressed, and resolved, at COP26", according to Antonio Guterres, who calls on all countries to commit to a zero emission goal by 2050. "Our future is at stake".


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