Climate: a threshold of + 1.5 ° C could be reached by 2025, warns the UN


There is a 40% chance that the average temperature over a year will exceed by 2025 a threshold of 1.5 degrees above pre-industrial levels, the target of the Paris Agreement to combat global warming, the UN warned on Thursday.

Influenced by climate change, the last decade has seen record temperatures: in 2020, it thus joined 2016 at the highest level of the warmest years ever recorded in the world, with an average of 1.25 ° C above the pre-industrial period.

However, the Paris Agreement, concluded in 2015, sets the goal of “keeping the increase in average planetary temperature at well below 2 ° C compared to pre-industrial levels, continuing the measures taken to limit the temperature rise to 1.5 ° C (which would significantly reduce risks) and the effects of climate change “.

Arctic: ice pack, predicted victim of global warming (AFP – Cléa PÉCULIER)

But the likelihood that the latter threshold will be crossed at least during the calendar year is steadily increasing, a study conducted by the British Meteorological Office for the World Meteorological Organization (WMO), a specialized UN agency, showed on Thursday.

“The average annual global temperature is likely to be 40% to be temporarily above 1.5 ° C at least pre-industrial values ​​for at least one of the next five years, and that probability grows over time,” the WMO points out in its presentation “Annual to Ten-Year Global Bulletin climate forecasts “.

In addition, “There is a 90% probability that at least one year between 2021 and 2025 will become the warmest ever recorded, and thus dethroned in 2016.”

Even if this overrun was only temporary, “this study shows, with great scientific certainty, that we are approaching the lower limit of the Paris Agreement in a measurable and relentless way,” Petteri Taalas, head of the WMO, points out in this presentation.

Sea level rise (AFP - Jonathan WALTER)

Sea level rise (AFP – Jonathan WALTER)

And warn of the consequences, as “rising temperatures mean increased ice melting, rising sea levels, increased heat waves and other extreme weather events, as well as greater consequences on food safety, health, the environment and sustainable development.”

Other experts pointed out that a temporary excess of 1.5 ° C would not necessarily mean the end of the Paris Agreement targets, such as Joeri Rogelj of Imperial College London. “But that’s still very bad news,” he said. “This tells us once again that actions in the context of global warming have so far been completely insufficient and that there is an urgent need to reduce emissions (greenhouse gases) to zero in order to stop warming.”



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