Rapid Desertification in Parts of Central Asia Blamed on Climate Change

Desert climates have spread north by up to 100 kilometers in parts of Central Asia as global temperatures have risen since the 1980s, according to a climate report.

The study, which was published on May 27 in Geophysical Research Letters, also revealed that temperatures have risen in Central Asia over the last 35 years, including parts of Uzbekistan, China, and Kyrgyzstan. Mountainous regions have become hotter and wetter during this time, possibly speeding up the retreat of some major glaciers.

Jeffrey Dukes, an ecologist at the Carnegie Institution for Science's Department of Global Ecology in Stanford, California, explained that such changes endanger ecosystems and the living creatures that rely on ecosystems - animals and humans included. According to Dukes, the findings are a great first step in informing mitigation and adaptation policies.

Higher Temperatures

More than 60% of Central Asia experiences a dry climate with little rainfall. Because water is scarce for plants and other organisms, much of the region is vulnerable to rising temperatures, which increases water evaporation in the soil and increases the risk of drought. Previous climate-change research reported average changes in temperatures and rainfall for large parts of Central Asia2,3, but this provided limited localized information for residents, according to study co-author Qi Hu, an Earth and climate scientist from the University of Nebraska, Lincoln.

According to Hu, people need to know the important subtleties of climate change in specific areas.

Hu and climate scientist Zihang Han of Lanzhou University in China divided Central Asia into 11 climate types using air temperature and precipitation data from 1960 to 2020.

They discovered that since the late 1980s, the desert climate zone in northern Uzbekistan and Kyrgyzstan, southern Kazakhstan, and the Junggar Basin in northwestern China has expanded eastwards and northwards by as much as 100 kilometers. According to Hu, this is a significant expansion that has had a cascading effect on nearby climate zones, which have also become drier. Between 1990 and 2020, the annual average temperature in some areas was at least 5 degrees Celsius higher than it was between 1960 and 1979, with summers becoming drier and rainfall falling mostly in the winter.

Plant communities will become dominated by species adapted to hotter and drier conditions as temperatures rise and rainfall decreases, according to Dukes. He goes on to say that this will have ramifications for grazing animals that rely on the steppe or grasslands for their food. Long periods of drought, he adds, will reduce the land's productivity until it becomes 'dead' soil in some areas.

In mountainous areas, the team discovered a different situation. Rising temperatures have been accompanied by an increase in the amount of precipitation that falls as rain rather than snow in the Tian Shan range of northwestern China. Higher temperatures and rainfall contribute to ice melting at high elevations, which Hu believes may explain the range's glaciers shrinking at an unprecedented rate.

According to Troy Sternberg, a geographer at the University of Oxford in the United Kingdom lost ice will not be replenished as snowfall declines, resulting in less meltwater flowing to people and crops in the future.

Global problem

According to Mickey Glantz, a climate scientist at the University of Colorado Boulder, desertification is a problem in Central Asia and other parts of the world. However, rather than relying solely on climate classification, researchers should look at indicators such as dust storms and heat waves to conclude definitively that deserts are expanding.

Desertification is exacerbated by human activities such as mining and agriculture, according to Sternberg. As a result, Central Asian governments should prioritize sustainable agriculture and urbanization. He stated that Central Asia, like the rest of the world, should pay attention to climate change and strive to become more adaptable.