Last year’s Northern Hemisphere summer was the hottest in 2,000 years, according to a new study released Tuesday.
Scientists previously announced that 2023 was the warmest year globally since records began in 1850, but a study in the journal Nature suggests that human-caused climate change has pushed summer highs far beyond anything seen in two millennia.
“We shouldn’t be surprised by that,” study lead author Jan Esper told AFP.
“To me, it’s just a continuation of what we started with the release of greenhouse gases that cause global warming,” said Esper, a professor of climatology at Germany’s Johannes Gutenberg University.
Scientists used tree-year data from sites across the Western Hemisphere to estimate global temperatures between the first century AD and 1850, before the advent of modern instruments.
A conservative estimate showed that 2023 was at least 0.5 degrees Celsius warmer than the hottest Northern Hemisphere summer in that period, which was in 246 AD.
Otherwise, it was warmer by as much as 1.19 degrees.
Study co-author Max Torbenson told reporters that 25 of the past 28 years exceeded the summer highs of 246 — the warmest before modern temperature records began.
