Last summer, as wildfires swept across the Mediterranean, roads buckled in Texas and heatwaves strained power grids in China, it was not just the warmest summer on record, but the hottest one in some 2,000 years, new research has found.
European scientists last year established that the period from June through August was the warmest in records dating back to 1940 - a clear sign of climate change fueling new extremes.
But the summer heat of 2023 in the Northern Hemisphere also eclipses records over a far longer time horizon, a study in the journal Nature found on Tuesday.
"When you look at the long sweep of history, you can see just how dramatic recent global warming is," said study co-author Jan Esper, a climate scientist at Johannes Gutenberg University in Germany.
Summer 2023 saw land temperatures between 30 and 90 degrees North of latitude reach 2.07 degrees Celsius (3.73 degrees Fahrneheit) higher than pre-industrial averages, the study said.