The year 2023 continues to multiply worrying climate records. After an unprecedented summer and an even more surprising month of September, it is now the hottest ever measured over the first nine months, approaching an anomaly of 1.5°C compared to the pre-industrial era.
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 humanity's greenhouse gas emissions, announced Thursday, October 5, the Climate Change Service (C3S) of the European Copernicus Observatory.
And this average, already 0.05°C higher than for the record year of 2016, could further increase over the last three months, given the strengthening of El Niño. This cyclical weather phenomenon over the Pacific Ocean, 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 long periods, decades and not single years. The Intergovernmental Panel on Climate Change (IPCC), mandated by the United Nations (UN), predicts that this threshold of 1.5°C will be reached by the years 2030-2035.
September, hottest month on record
And 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.
Meanwhile, “September 2023 was the hottest September on record globally,” continuing a streak of global monthly records that began in June. July 2023 holds the absolute record for all months.
With an average global surface temperature of 16.38°C, the past month exceeds the September 2020 record by an “extraordinary” margin of 0.5°C, Copernicus announced on Thursday. September 2023 is thus “1.75°C warmer than the average September over the period 1850-1900,” Copernicus added.
While global temperature variations are typically measured in a few tenths of a degree, September 2023 is 0.9°C above the 1991-2020 September average, “the largest 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. In the same month, torrential rains from Storm Daniel, likely worsened by climate change according to preliminary studies, devastated northeastern Libya and Greece.
The pope's cry of alarm
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: Antarctic sea ice remains at its lowest for the season, while Arctic sea ice is 18% below average, according to C3S.
The overheating of the world's seas, which absorb 90% of the excess heat caused by human activity since the pre-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 high and the second highest measurement behind that of August 2023.
Faced with this situation, humanity's responses are "insufficient as the world (...) collapses" and approaches a "breaking point", lamented Pope Francis on Wednesday in a text in form of cry of alarm two months before a decisive UN climate conference.
During this COP28, in Dubai, the theme of phasing out fossil fuels will be at the heart of tough negotiations between countries, unable to date to reconcile the requirements of the Paris agreement to limit warming and ensure the aspirations for the development of all humanity.
