Projections of desertification trends in Central Asia under global warming scenarios

Xiaofei Ma; Jianting Zhu; Wei Yan; Chengyi Zhao

doi:10.1016/j.scitotenv.2021.146777

Projections of desertification trends in Central Asia under global warming scenarios

Sci Total Environ. 2021 Aug 10:781:146777. doi: 10.1016/j.scitotenv.2021.146777. Epub 2021 Mar 27.

Authors

Xiaofei Ma¹, Jianting Zhu², Wei Yan³, Chengyi Zhao⁴

Affiliations

¹ State Key Laboratory of Desert and Oasis Ecology, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, 818 Beijing South Road, Urumqi 830011, China; Research Center for Ecology and Environment of Central Asia, Chinese Academy of Sciences, 818 Beijing South Road, Urumqi 830011, China; University of Chinese Academy of Sciences, Beijing 100049, China.
² Department of Civil and Architectural Engineering, University of Wyoming, Laramie, WY 82071, USA.
³ School of Geographic Sciences, Xinyang Normal University, Xinyang 464000, China.
⁴ School of Geographical Sciences, Nanjing University of Information Science and Technology, Nanjing 210044, China. Electronic address: zhaocy@nuist.edu.cn.

PMID: 33812115
DOI: 10.1016/j.scitotenv.2021.146777

Abstract

Central Asia (CA) is a core area of global desertification, but the effect of the intensifying "global greening" policy on the desertification process under global warming scenarios in CA remains unclear. Based on multi-source remote sensing data and Inter-Sectoral Impact Model Intercomparison Project (ISIMIP) 2b climate data, this study investigated desertification in CA using actual evapotranspiration (ETa), temperature and precipitation as driving factors. Coupling with the CA-Markov model, the inversion method of desertification was improved, and the evolution normal form of desertification in CA was proposed. Finally, spatio-temporal variations of desertification in CA were quantified. The results indicate that temperature, precipitation, and normalized difference vegetation index (NDVI) in CA increased during the historical period (1980-2015), with sudden changes in 1994. In contrast, although ETa exhibited fluctuating increases (7.41 mm/10 yr) during this period, no sudden changes were observed in 1994. In the future (2006-2099), the climate of CA will become warmer and wetter. With reference to 1980-2005, precipitation under global warming of 2.0 °C (GW2.0) will be higher than that under global warming of 1.5 °C (GW1.5) by 10.3 mm, and ETa will increase by 20.88 mm and 27.54 mm under GW1.5 and GW2.0, respectively. Although the area of desert lands has decreased (5.94 × 10⁴ km²/10 yr), the area of potential desert lands has increased (0.17 × 10⁴ km²/10 yr). With global warming, this situation will continue to intensify, mainly in Xinjiang of China, and Kazakhstan. The Aral Sea plays an important role in the desertification of CA. The potential increase in desert land under GW2.0 is equivalent to the current water area of the Aral Sea. The findings could provide policy support for combating desertification in CA and promoting the achievement of the Sustainable Development Goals.

Keywords: Actual evapotranspiration; Aral Sea; Central Asia; Desertification; Global change ecology; Global warming.