The world has just experienced its hottest August on record, with temperatures across land and oceans reaching new highs as a powerful El Niño event continues to build, raising fears that the extreme heat could intensify further before the year ends.
The Copernicus Climate Change Service said Thursday that the average global air temperature in August stood at 16.96C, edging past the previous record of 16.95C recorded in July 2023.
The difference was only 0.01C, prompting the European climate monitor to treat August and July 2023 as joint-highest months because of the narrow margin.
The latest record came after an exceptionally hot summer that brought severe heatwaves and wildfires across several parts of the world. Western Europe and the contiguous United States both experienced their hottest summers ever recorded.
Although Copernicus has temperature records dating back to 1940, other evidence from ice cores, tree rings and coral skeletons provides a much longer view of Earth's climate.
"Humans haven't seen temperatures as hot as today for, arguably, at least the last 100,000 years," Samantha Burgess from the European Centre for Medium-Range Weather Forecasts, which oversees Copernicus, told AFP.
UN climate chief Simon Stiell said the latest temperature figures showed the growing cost of continued fossil fuel use.
"evidence is irrefutable: this is the spiralling price of humanity's fossil fuel addiction".
Oceans also reach record levels
The extreme heat was not limited to land, with the world's oceans also experiencing an unusually hot period.
Simon van Gennip from Mercator Ocean International said ocean temperatures had reached record levels for three consecutive months during the summer.
Some ocean areas were affected by marine heatwaves lasting more than 60 days, a sign of how persistent the unusually high temperatures had become.
Global sea surface temperatures also reached a new daily record in August, while the month matched the highest ocean temperature ever measured.
Copernicus said long-term global warming caused by the burning of coal, oil and gas remained the main reason behind the rising temperatures. At the same time, warming waters in the Pacific are adding to the heat as a major El Niño event becomes stronger.
El Niño develops when parts of the Pacific Ocean become unusually warm. It can then alter rainfall and wind patterns across large parts of the world, increasing the risk of extreme weather in areas far from the Pacific.
Global weather forecasters expect the current El Niño to reach its strongest point later this year, with its strength potentially exceeding anything recorded during the modern period.
The US National Oceanic and Atmospheric Administration said Thursday that there was a 75 percent chance the event "would exceed the strength of previous El Nino events dating back to 1950".
Its effects are already being felt in Indonesia, according to Copernicus, where an unusually long and intense dry season has helped fuel wildfires that have burned large areas of Borneo island.
Scientists say the record August heat may not represent the worst of the current period.
El Niño normally causes a temporary rise in global temperatures, adding another source of heat to the warming already caused by climate change.
The added warmth can also affect temperatures after the event reaches its peak, with the year that follows an El Niño often becoming the hottest on record.
Scientists expect 2027 could set a new global temperature record, although Burgess said 2026 could also finish among the most extreme years ever recorded.
"We expected 2026 to be top five but now it's second place, maybe in first place... We've seen a striking reminder of how quickly the climate system can shift when multiple drivers have aligned," she said.
Burgess warned that the combined effect of long-term warming and El Niño could lead to more records being broken over the next several months.
The double whammy of climate change and El Nino would mean records "falling over the next six months", said Burgess, an ocean scientist and strategic lead for at ECMWF.
Friederike Otto, a climate scientist from Imperial College London, said the continued burning of fossil fuels would keep pushing global temperatures higher.
"Climate change makes every El Nino hotter, and until we stop burning coal, oil, and gas these record-shattering months will simply keep on coming," said Friederike Otto, a climate scientist from Imperial College London.
Europe, US suffer extreme heat
Western Europe recorded its hottest summer ever, surpassing the previous record set in 2003.
The continent was hit by repeated heatwaves that disrupted daily life, forced schools to close, reduced river levels and left dry areas more exposed to destructive wildfires.
Between mid-July and mid-August, Europe's EuroMomo monitoring platform estimated that more than 32,000 excess deaths occurred across the continent.
Other parts of the world also experienced exceptional temperatures during the season.
Copernicus said the period covering June, July and August tied with 2024 as the warmest summer globally on record.
An AFP analysis of Copernicus data found that areas inhabited by about 900 million people experienced their hottest July ever recorded.
In the United States, NOAA said on Wednesday that the contiguous US had also endured its hottest summer on record.
Burgess described the summer's conditions as "exceptional" and warned that the climate would continue becoming more extreme unless global emissions are brought down.
The summer has been "exceptional", but the climate will "continue to get more extreme unless we turn off the tap to global emissions", said Burgess.