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.
But tree rings, which record temperature information far further back than even Victorian scientific records, now show just how unprecedented last year’s scorching temperatures were.
Researchers say that temperatures last June, July and August were nearly 4C warmer than the coldest summer two millennia ago.
Climate scientists have repeatedly shown that global temperatures have been rising rapidly in recent decades. According to the UN’s climate body, the last time the world was consistently this warm may have been more than 100,000 years ago.
Why compare the hottest summer on record to the coolest summer 2,000 years ago? What am I missing?
Later in the article
The warmest summer in the tree ring reconstruction before industrial times was year 246, but the researchers say that even this does not come close to the recent warmth.
Even taking account of the large uncertainties, the authors say summer 2023 surpassed this range of natural climate variability by 0.5C at the very least.
It is also worth looking at the graph later in the article, which shows that over the past 2k years the temperature has maintained a baseline, and post-industrial era it turned into a hockey stick.
