Based on an analysis of ancient tree rings that date all the way back to the year 1, last summer was the hottest in the past 2,000 years.

Researchers used tree ring data to compare the extreme heat of 2023 to two millennia of summer temperatures in the Northern Hemisphere.

Clues hidden deep in the trunks of ancient trees have revealed that last summer was the northern hemisphere's hottest in 2,000 years. Last year had already been confirmed as the world's warmest on record by a large margin, at least since 1850, due to climate change.

Researchers have found that 2023 was the hottest summer in the Northern Hemisphere in the past two thousand years, almost four degrees warmer than the coldest summer during the same period.

On a regional scale, global warming exceeded the Paris agreement’s upper climate target in the northern hemisphere.

Summer 2023 was hottest in 2,000 years in ‘dramatic’ global warming, study shows - The summer months of June, July and August 2023 were at least 0.5C hotter than the extremes of a naturally varying climate,