(CU)_Recent summer droughts and the series of heatwaves in Europe were the most severe the region has seen in more than 2,000 years, according to a new research published in the journal Nature Geoscience. The study, which analysed tree rings dating as far back as the Roman empire, found a long-term drying trend which intensified since 2014.
According to the research, these heatwaves were caused by subtle changes in Earth’s orbit, and not by volcanic activity or solar cycles. The scientists also found that changes in the circulation of air as well the position of the jet stream over the continent caused the droughts, while climate change was the possible underlying driver of this.
These heatwaves have caused devastating consequences, causing thousands of early deaths, igniting forest fires and destroying crops, although the scientists also warned that more extreme and more frequent heatwaves and droughts are yet to come.
“We’re all aware of the cluster of exceptionally hot and dry summers we’ve had over the past few years,” Prof Ulf Büntgen of Cambridge University, who led the study, said. “Our results show what we have experienced is extraordinary. The series is unprecedented for the last 2,000 years.”
He further noted that climate change causes extreme conditions to be more frequent, which could be devastating for agriculture, ecosystems and societies as a whole.
Meanwhile, Dr Friederike Otto, of Oxford University, highlighted the significance of the recent study as she noted that the lack of historic data often hindered the clear identification of the drivers of extreme events, making the recent findings important and useful.
“It corroborates from a long-term perspective that the huge increase in heat extremes observed over Europe in the summer, which has clearly been attributed to human-induced climate change, does indeed change the nature of summer in Europe,” she said.
The study, published on Monday (15 March), analysed 27,000 growth rings from 147 oak trees. It used living oaks and timber from old buildings for the last century, while oak that had been preserved in river deposits or gravel beds were used for the middle ages. For the Roman period, the researchers used remains such as wood used to construct wells.
Although previous studies used the width and wood density of the tree rings, the research led by Büntgen however, used measurements of carbon and oxygen isotopes to determine how much water was available to the trees, which gave a record of droughts. The wood samples, which represent climate conditions across central Europe, came from Germany and the Czech Republic.
