New research published in the journal Science predicts the future of Mongolia’s semi-arid plateau, saying that if the last two decades show any clue, the region is in for extreme heatwaves and droughts. The study is based on data from tree-rings that depict soil moisture and climate conditions.
According to the researchers, soil drying exacerbates the high temperatures experienced in the region. This creates a positive feedback loop, wherein soil drying creates the ideal conditions for heatwaves, and heatwaves trigger more soil drying.
As co-author Deliang Chen from Sweden's University of Gothenburg puts it: "The result is more heatwaves, which means more soil water losses, which means more heatwaves -- and where this might end, we cannot say."
The team collected tree ring data from trees living on the high-altitude Mongolian Plateau. From their analysis, they created records of heatwave and soil moisture, showing that recent consecutive years of high temperatures and droughts are record-breaking when compared to histories of the last 250 years.
"The conifer trees respond strongly to anomalously high temperatures," said co-author Hans Linderholm, from the University of Gothenburg. "By examining their growth rings, we can see their response to the recent heatwaves, and we can see that they do not appear to have experienced anything like this in their very long lives."
Their findings confirm that soil moisture, in addition to the water in lakes, is evaporating at unprecedented rates. "Now we are seeing that it isn't just large bodies of water that are disappearing," said corresponding author Jee-Hoon Jeong of Chonnam National University in South Korea. "The water in the soil is vanishing, too."
"This may be devastating for the region's ecosystem which is critical for the large herbivores, like wild sheep, antelope, and camels," lead author Peng Zhang, who is a researcher at the University of Gothenburg. "These amazing animals already live on the edge, and these impacts of climate change may push them over."
The researchers warn that these conditions may soon push the Mongolian Plateau over its tipping point, meaning the region would transform into one of permanent aridness.