Hot history: Tree rings show that last northern summer was the warmest since year 1
A new study finds that the broiling summer of 2023 was the hottest in the Northern Hemisphere in more than 2,000 years
The broiling summer of 2023 was the hottest in the Northern Hemisphere in more than 2,000 years, a new study found.
When the temperatures spiked last year, numerous weather agencies said it was the hottest month, summer and year on record. But those records only go back to 1850 at best because it's based on thermometers. Now scientists can go back to the modern western calendar's year 1, when the Bible says Jesus Christ walked the Earth, but have found no hotter northern summer than last year's.
A study Tuesday in the journal Nature uses a well-established method and record of more than 10,000 tree rings to calculate summertime temperatures for each year since the year 1. No year came even close to last summer's high heat, said lead author Jan Esper, a climate geographer at the Gutenberg Research College in Germany.
Before humans started pumping heat-trapping gases into the atmosphere by burning coal, oil and natural gas, the hottest year was the year 246, Esper said. That was the beginning of the medieval period of history, when Roman Emperor Philip the Arab fought Germans along the Danube River.
