The series of severe droughts and heatwaves in Europe since 2014 is the most extreme for more than 2,000 years, research suggests.
The study analysed tree rings dating as far back as the Roman empire to create the longest such record to date. The scientists said global heating was the most probable cause of the recent rise in extreme heat.
The heatwaves have had devastating consequences, the researchers said, causing thousands ofearly deaths, destroying crops and igniting forest fires. Low river levels halted some shipping traffic and affected the cooling of nuclear power stations. Climate scientists predict more extreme and more frequent heatwaves and droughts in future.
The study also found a gradual drying of the summer climate in central Europe over the last two millennia, before the recent surge. The scientists ruled out volcanic activity and solar cycles as causes of this long-term trend and think subtle changes in Earth’s orbit are the cause.
“We’re all aware of the cluster of exceptionally hot and dry summers we’ve had over the past few years,” said Prof Ulf Buntgen, of Cambridge University, who led the study. “Our results show what we have experienced is extraordinary. The series is unprecedented for the last 2,000 years.” The available data ends in 2018, but 2019 and 2020 also had very hot European summers.