Severe Heat Waves and Droughts Hit Eurasia Back-to-Back

Over the past two decades, from the grain stores of Ukraine to towns in northern China, Eurasia has experienced a notable increase in droughts following extreme heat events. Tree ring analysis extending back nearly three centuries indicates that human-induced climate change is a significant factor in the acceleration of these combined catastrophes.

This phenomenon presents a severe threat due to the way heat and drought reinforce each other. Elevated temperatures deplete soil moisture, and droughts further reduce the humidity needed to mitigate the impact of subsequent heat waves. This harmful cycle contributes to decreased agricultural productivity and a heightened risk of wildfires.

Certain regions in Eurasia have encountered similar heat and drought patterns in the past, but researchers assert, “current developments exceed natural fluctuations,” according to Hans Linderholm, a researcher at the University of Gothenburg, Sweden.

The complete landscape became apparent only after Linderholm and his team compiled tree ring data covering Eurasia from 1741, which reflects temperature and precipitation variations. This allowed them to recreate a comprehensive distribution of high- and low-pressure systems that influence wet and dry conditions across the continent.

Researchers identified specific phenomena affecting the area, termed the “heatwave motion train of iolarism,” which has intensified since 2000, amplifying anomalies beyond historical measurements. This alteration is associated with atmospheric pressure changes prompted by warming in the North Atlantic and increased precipitation in some regions of North Africa, both linked to anthropogenic climate change.

Rising local temperatures can directly worsen extreme heat and drought situations. However, new research indicates that climate change is modifying the dynamics between distant atmospheric regions (referred to as teleconnections), further complicating the situation, Linderholm explains.

Climate model forecasts predict worsening conditions under all scenarios except for those with the lowest emissions. “We observe a distinct, robust trend in this new teleconnection pattern, suggesting that impacts will escalate in both speed and severity,” states Linderholm.

“It is difficult to envision how [the most affected regions will] recover,” he concludes.