The climate forecasts are not improving. According to a new climate bulletin released Tuesday by the United Nations World Meteorological Organization (WMO), there is a one in two chance that the 1.5°C threshold will be temporarily crossed within five years. It should be noted that the UN is not speaking here of a lasting overrun of this threshold, in the sense understood by the Paris climate agreement.
The probability of a temporary overshoot of this threshold, indexed to pre-industrial values, has steadily increased since 2015, when this risk was close to zero. It has thus increased from 10% between 2017 and 2021, “to almost 50% for the period 2022-2026”, indicates the WMO. However, there is only a small probability (10%) that the five-year average exceeds the threshold of +1.5°C.
A threshold “harmful for populations and for the entire planet”
“The 1.5°C figure is not a randomly chosen statistic. It indicates the point at which the effects of climate will be increasingly harmful for people and for the entire planet,” explained WMO Secretary-General Petteri Taalas. “As long as we continue to emit greenhouse gases, temperatures will continue to rise. At the same time, our oceans will continue to warm and acidify, sea ice and glaciers will continue to melt, sea levels will continue to rise, and extreme weather will continue to intensify,” he said. he warned, stressing that the warming of the Arctic was “particularly marked”.
According to this bulletin established by the United Kingdom Meteorological Service (Met Office), it is very likely (93%) that at least one of the years between 2022 and 2026 will become the hottest on record. This record is currently held by the year 2016, marked by a powerful El Niño episode. 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).