Towards a disaster scenario? There is a one in two chance that the average annual global temperature will temporarily be 1.5°C above pre-industrial values for at least one of the next five years, the UN announced on Monday (May 9).
A temporary crossing of this threshold over a year is not, however, synonymous with a lasting exceeding of this threshold, in the sense understood by the Paris Climate Agreement. This agreement aims to contain the increase in the global average temperature to well below 2 degrees Celsius compared to pre-industrial levels, and if possible to 1.5 degrees.
According to a new climate bulletin published on Tuesday by the United Nations World Meteorological Organization (WMO), the probability of a temporary exceedance of the 1.5°C threshold has risen steadily since 2015, the year where this risk was close to zero.
For the years between 2017 and 2021, the probability of exceedance was 10%. She has passed “nearly 50% for the period 2022-2026”, says the WMO. But there is only a small probability (10%) that the five-year average exceeds the threshold of +1.5°C.
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“This study shows, with great scientific reliability, that we are getting significantly closer to the moment when we will temporarily reach the lower limit of the Paris Agreement. The figure of 1.5°C is not a randomly chosen statistic. It indicates the point at which the effects of the climate will be increasingly harmful for populations and for the entire planet.explained WMO Secretary-General Petteri Taalas.
According to this bulletin on annual to decadal climate forecasts on a global scale, produced by the United Kingdom Met Office (Met Office), which is WMO’s main center for this type of forecast, it is very likely ( 93%) that at least one of the years between 2022 and 2026 becomes the hottest on record.
This record is currently held by the year 2016, which was marked by a powerful El Niño episode, a natural oceanic phenomenon that leads to a rise in temperatures. It is also 93% likely that the average temperature for the period 2022-2026 will be higher than that of the last five years (2017-2021).
In 2021, the planet’s average temperature will be 1.11°C higher than the benchmark pre-industrial era, according to a recent WMO report on the state of the global climate. The final version of the document will be published on May 18.