Summer 2024 sweltered to Earth's hottest on record, making it more likely that this year will end up as the warmest on record, European climate service Copernicus said on Friday.
The records were set just last year with a temporary boost from an El Nino dialling up temperatures and extreme weather, scientists said.
The northern meteorological summer - June, July and August - averaged 16.8C, according to Copernicus.
That is 0.03C warmer than the old record in 2023.
Copernicus records go back to 1940, but American, British and Japanese records, which start in the mid-19th century, show the last decade has been the hottest since regular measurements were taken and likely in about 120,000 years, according to some scientists.
The last two Augusts tied for the hottest globally at 16.8C. July was the first time in more than a year that a month did not set a record, but because June 2024 was so much hotter than June 2023, this summer as a whole was the hottest, Copernicus director Carlo Buontempo said.
"What those sober numbers indicate is how the climate crisis is tightening its grip on us," said Stefan Rahmstorf, a climate scientist at the Potsdam Institute for Climate Research, who wasn't part of the research.
In the UK meanwhile, provisional Met Office data shows this was the coolest summer since 2015, with a mean daily temperature of 14.37C, which is 0.22C below average.While this bucked the trend of warm summers seen in recent years, the Met Office pointed out it would still be considered warmer than average if compared with 1961-1990, when the figure was 13.78C.
The dew point - one of several ways to measure the air's humidity - probably was at or near record high this summer for much of the world, Mr Buontempo said.
Until last month Mr Buontempo, like some other climate scientists, was on the fence over whether 2024 would beat the hottest year record set last year, mostly because August 2023 was so enormously hotter than average. But after August 2024 matched 2023, Mr Buontempo is "pretty certain" this year will end up the hottest on record.
"In order for 2024 not to become the warmest on record, we need to see very significant landscape cooling for the remaining few months, which doesn't look likely at this stage," he said.
With a forecasted La Nina - a temporary natural cooling of parts of the central Pacific - the last four months of the year may no longer be record-setters like most of the past year and a half, but it is not likely cool enough to keep 2024 from breaking the annual record, Mr Buontempo said.
These are not just numbers in a record book, but weather that hurts people, climate scientists said.
Jennifer Francis, a climate scientist at the Woodwell Climate Research Centre in Cape Cod, said there has been a deluge of extreme weather of heat, floods, wildfires and high winds that are violent and dangerous.
"Like people living in a war zone with the constant thumping of bombs and clatter of guns, we are becoming deaf to what should be alarm bells and air-raid sirens," Ms Francis said in an email.
