Global temperatures continue to crush records: after an unprecedented summer and a month of September that “beyond comprehension”, 2023 is now the hottest year ever measured over the first nine months, approaching a an anomaly of 1.5°C compared to the pre-industrial era.
A dire warning two months before COP28, in Dubai, during which the fate of fossil fuels, the main cause of warming, will once again pit producing countries against those who wish to set a date for the exit of oil, gas and coal.
From January to September, “the global average temperature is 1.40 °C above the pre-industrial average (1850-1900)”, before the effect on the climate of greenhouse gas emissions from the humanity, the Climate Change Service (C3S) of the European Copernicus Observatory announced on Thursday.
And this average, already 0.05°C higher than for the record year of 2016, could further increase over the last three months of the year, given the strengthening of El Niño. This cyclical weather phenomenon over the Pacific, synonymous with additional warming, generally peaks around the Christmas period.
“It is not certain that 2023 will reach 1.5°C. But we are quite close,” Carlo Buontempo, director of C3S, told Agence France-Presse.
Reaching this symbolic bar would not mean that the most ambitious limit of the Paris agreement has been reached, because the latter refers to the evolution of the climate over several years.
The IPCC, bringing together climate experts mandated by the United Nations, predicts that the threshold of 1.5°C will be reached in the years 2030-2035 (compared to an average of 1.2°C in recent years).
The World Meteorological Organization estimated in the spring that the bar would be crossed for the first time in a full year only in the next five years.
“Strongest monthly anomaly”
In the meantime, “September 2023 was the hottest September on record globally”, continuing a series of global monthly records started in June. July 2023 holds the absolute record, all months combined.
With an average temperature of 16.38°C on the surface of the globe, the past month exceeds the record of September 2020 by an “extraordinary” margin of 0.5°C, Copernicus said on Thursday.
September 2023 is thus “1.75°C warmer than the average September over the period 1850-1900,” added Copernicus.
While variations in global temperatures are generally measured in a few tenths of a degree, September 2023 is 0.9°C above the September average over the period 1991-2020, i.e. “the strongest monthly anomaly” ever measured by Copernicus, whose complete database dates back to 1940.
All continents were affected by extraordinary anomalies. In Europe, September 2023 set a new continental record for the first month of meteorological autumn; it was over 35°C in France until the beginning of October. “We have just experienced the most incredible month of September from a climatic point of view. This is beyond comprehension,” commented Carlo Buontempo of C3S.
In the same month, torrential rains from the storm Danielprobably worsened by climate change according to preliminary studies, devastated northeastern Libya and Greece.
The south of Brazil and Chile also experienced the flood in September while the Amazon is currently hit by an extreme drought, which affects more than 500,000 inhabitants.
And the poles are losing ice: the Antarctic sea ice remains at a record low level for the season, while the Arctic sea ice is 18% below average, according to the C3S.
“This type of event is consistent with predictions made over the past two decades,” said Doug McNeall, a climatologist at the UK Met Office’s Hadley Centre. “It is shocking to see these records being broken and the impact this is having on people’s lives and ecosystems,” he told Agence France-Presse.
The overheating of the world’s seas, which absorb 90% of the excess heat caused by human activity since the industrial era, plays a major role in these observations.
For the Copernicus measurement system, the average sea temperature reached 20.92 ° C in September, a new monthly record and 2e highest measurement behind August 2023.