The areas of the planet that sweltered under above-normal heat during the shockingly warm month of September in 2023 have been revealed in a newly shared NASA map.
The map shows how regions across Europe, East Asia, South America, and the Northern U.S., among many other areas, saw temperatures as high as 7.2 degrees F above the 1951-1980 average during that month.
"In September, the record was broken by an absolutely astonishing 0.5 degrees Celsius [0.9 F]," Gavin Schmidt, the director of NASA's Goddard Institute for Space Studies (GISS) told NASA Earth Observatory. "That has not happened before in the GISS record."
The year 2023 is currently the warmest on record, hitting global average temperatures of 2.66 degrees F above pre-industrial levels (the average between 1850-1900).
"It's humbling, and a bit worrying, to admit that no year has confounded climate scientists' predictive capabilities more than 2023 has," Schmidt wrote in a commentary in the journal Nature in March 2024.
In September 2023, global temperatures were 3.15 degrees F higher than pre-industrial September averages.
"September 2023 was the warmest September on record globally, with an average surface air temperature of 16.38 C [61.5 F], 0.93 C above the 1991-2020 average for September and 0.5 C above the temperature of the previous warmest September, in 2020," the Copernicus Climate Change Service (C3S) explained in a report.
September 2024 was the first after a 15-month record streak of warm global temperatures to not be the hottest month on record, and was the second-hottest September after 2023.
Between January and September 2024, the global average temperature anomaly was 0.71 C (1.3 F) higher than the 1991-2020 average, which is a record high for the January–September period, and 0.34 F warmer than the same period of time in 2023. This average temperature anomaly would have to decrease by 0.72 F for the rest of this year for 2024 not to be warmer than 2023, according to C3S.
"After 10 months of 2024, it is now virtually certain that 2024 will be the warmest year on record and the first year of more than 1.5 C [2.7 F] above pre-industrial levels according to the ERA5 dataset," Samantha Burgess, deputy director of the C3S, said in a statement. "This marks a new milestone in global temperature records and should serve as a catalyst to raise ambition for the upcoming Climate Change Conference, COP29."
October 2024 was also exceedingly warm, becoming the second-warmest October on record worldwide.
In the U.S, October 2024 saw temperatures 4.9 F above average across the contiguous states, marking the second-warmest month on record overall at 59 F. Utah, Arizona, New Mexico and Texas all had their hottest Octobers ever.
"Warming in 2023 was head-and-shoulders above any other year, and 2024 will be as well," Schmidt said. "I wish I knew why, but I don't. We're still in the process of assessing what happened and if we are seeing a shift in how the climate system operates."
While experts agree global temperatures are warming due to climate change, 2023 and 2024 represent even sharper increases in temperatures than expected under current models. Schmidt has been researching what could be causing these sudden spikes in temperature, investigating if it could be the effects of the 2022 eruption of the Hunga Tonga-Hunga Ha'apai volcano in the Pacific Ocean, shifts in greenhouse gas emissions, incoming solar radiation or perhaps the airborne particles called aerosols. But none of these factors offer an adequate explanation for the surprising heat in 2023.
"All of these factors explain, perhaps, a tenth of a degree in warming," Schmidt said. "Even after taking all plausible explanations into account, the divergence between expected and observed annual mean temperatures in 2023 remains near 0.2 C—roughly the gap between the previous and current annual record."
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