Uncertainties of Climate Change in Arid Environments of Central Asia

This article examines the key uncertainties of climate change in the Central Asian republics of the former USSR—a vast arid region and a classic example of complex and poorly understood interactions between the regional responses to global climate change and the local human-induced desertification. Based on paleoanalogous scenarios, Central Asian deserts are often predicted to become wetter as a result of global warming because they are located north of 30° latitude. However, despite some similarities between the paleoclimate changes and greenhouse warming, such predictions have very serious limitations. Climate models predict that the temperature in arid Central Asia will increase by 1–2°C by 2030–2050, with the greatest increases in wintertime. Some models project greater aridity in the future though others project less aridity, and it is becoming increasingly apparent that climate change modeling in arid zones is extremely uncertain because of the extreme natural variability (both temporal and spatial) of the desert climate. The physical differences of climate change forcings imply that one might expect quite different regional responses to future human-induced climate change compared to the Holocene climate in terms of their rapidity and amplitude. Local and regional human impacts, such as massive irrigation, may have a stronger impact on the climatic system at the regional level than global climate change.

Keywords:

• paleoclimatology
• greenhouse warming
• climate models
• paleogeographic data
• human-induced desertification

Acknowledgments

The GCM scenarios were obtained from the IPCC Data Distribution Centre (http://ipcc-ddc.cru.uea.ac.uk). Historical monthly precipitation data were obtained from Tyndall Centre for Climate Change Research, University of East Anglia. We are grateful to Philip Micklin and two anonymous reviewers for helpful comments, and Kin Ma who helped with editing the final version of this manuscript.