Summer 2023 was the hottest in 2,000 years, says study

New research suggests 2023 was the warmest summer in 2,000 years, with heatwaves causing health issues worldwide.

The intense northern hemisphere summer heat that drove wildfires across the Mediterranean, buckled roads in Texas and strained power grids in China last year made it not just the warmest summer on record - but the warmest in some 2,000 years, new research suggests.

The stark finding comes from one of two new studies released on Tuesday, as both global temperatures and climate-warming emissions continue to climb.

Scientists had quickly declared last year's June to August period as the warmest since record-keeping began in the 1940s.

New work published in the journal Nature suggests the 2023 heat eclipsed temperatures over a far longer timeline - a finding established by looking at meteorological records dating to the mid-1800s and temperature data based on the analysis of tree rings across nine northern sites.

"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.

Last year's summer season temperatures on lands between 30 and 90 degrees north latitude reached 2.07 degrees Celsius (3.73 degrees Fahrenheit) higher than pre-industrial averages, the study said.

Based on tree ring data, the summer months in 2023 were on average 2.2 C (4 F) warmer than the estimated average temperature across the years 1 to 1890.