High temperatures across the Northern Hemisphere last summer were scorching and frequent enough to make it the hottest summer in two millennia, new research shows.
Weather records based on scientific instruments only goes back as far as 1850, noted researchers at Cambridge University in England. That data already had confirmed the summer of 2023 as the hottest ever recorded.
However, the Cambridge crew turned to tree ring data to reach back 2,000 years and last summer was still the hottest over that entire period of time.
"When you look at the long sweep of history, you can see just how dramatic recent global warming is," said study co-author Ulf Büntgen, a professor of geography at Cambridge. "2023 was an exceptionally hot year, and this trend will continue unless we reduce greenhouse gas emissions dramatically."
