Drought conditions may have devastating impacts in Eurasian regions like Karapinar in Türkiye
Yasin Akgul / AFP via Getty Images
Over the past two decades, the Eurasia expanses – of the Ukraine band in the cities of northern China – have seen a peak in extreme heat waves followed by droughts. A tree ring recording extending over almost three centuries suggests that human -origin climate change is to be blamed for the increase in these disastrous compound events.
This diagram can be particularly damaging because of the way heat and dryness feed on each other: high temperatures dry the soil, and drought then deprives it of humidity to cool things during the following heat wave. This vicious cycle has devastating impacts, lower agricultural yields at a higher risk of forest.
While some parts of Eurasia have already seen this drought scheme of thermal waves, “the current trend is just apart from natural variability”, says Hans Linderholm at the University of Gothenburg in Sweden.
The complete image only became clear after Linderholm and his colleagues assembled records of tree rings, which have kept the conditions of temperature and precipitation since 1741, of all Eurasia. They used it to reconstruct the large -scale distribution of high and low pressure systems which naturally lead to wet and dry conditions through the continent.
The researchers found a particular scenario in this region, which they call the “Drought train of the Trans-Eurasian heat wave”, has intensified since 2000, with the size of the heat and precipitation anomalies which jumped over those measured at any other time in the record. They connect this change to the disruption of atmospheric pressure caused by heating in the North Atlantic and an increase in precipitation in a part of North Africa – which are both associated with anthropogenic climate change.
The increase in local temperatures can also exacerbate directly Extreme heat and drought. But the new discovery shows how climate change also changes the relationships between the distant parts of the atmosphere – known as television – To disrupt things even more, said Linderholm.
The team's projections, based on climate models, suggest that things will get worse, except the lowest emission scenarios. “We see that this new Teleconnection model has a really distinct strong tendency, which means that things will go very quickly, and there will be more serious impacts,” explains Linderholm.
“We have trouble seeing how (the most affected places) will recover,” he says.
