Drought is one of the most damaging types of extreme climate, and is particularly commonplace in arid regions. Meanwhile, drought events have become more frequent and intense because of the increasing atmospheric evaporative demand induced by global warming. Therefore, understanding how droughts in arid regions respond to global warming, as well as producing reliable projections of their future changes and related risks, is essential to facilitate mitigation and adaption strategies for carbon neutrality and climate change.

 

Both the attribution of historical changes in drought and future projections of droughts rely heavily on climate modeling. However, reasonable drought simulations have remained a challenge. Thus, it is of great importance to examine how current state-of-the-art climate models perform in simulating drought in arid regions—an issue addressed in a recent study carried out by scientists from the Institute of Atmospheric Physics, Chinese Academy of Sciences.

 

"Our results confirm the capability of the latest climate models in capturing the primary characteristics of drought-related meteorological elements," explains YU Xiaojing, first author of the study. Nevertheless, the team also noticed that the long-term water deficit condition over arid regions in the examined models was underestimated, due to a larger water supply (precipitation) but weaker atmospheric water demand (potential evapotranspiration).

 

Observations reveal a significant increase in drought risk in arid regions since the 1980s, based on there having been a more widespread drought-affected area and a higher occurrence of drought. "State-of-the-art climate models are capable of reproducing the observed increasing trends in drought events and corresponding meteorological anomalies. However, the simulated changes in drought after the late 1990s are obviously underestimated. This indicates a weaker-than-observed response of drought in arid regions to global warming in current models," warns YU.

 

Associate Prof. ZHANG Lixia, corresponding author of the study, further stresses that "Our results have important implications for the application of the latest climate models in studies related to drought in arid regions. It is imperative to employ bias-correction approaches when using the outputs of these models to investigate the impacts of drought in arid ecosystems."

 

This research has been published in Advances in Atmospheric Sciences and Science China Earth Sciences, and was supported by funding from the Ministry of Science and Technology of China and the National Natural Science Foundation of China.

 

References:

Xiaojing Yu, Lixia Zhang*, Tianjun Zhou, Jianghua Zheng. 2023. Assessing the performance of CMIP6 models in reproducing droughts across global drylands. Advances in Atmospheric Sciences, https://doi.org/10.1007/s00376-023-2278-4.

Xiaojing Yu, Lixia Zhang*, Tianjun Zhou, Xing Zhang. 2023. Long-term changes in the effect of drought stress on ecosystems across global drylands. Science China Earth Sciences, 66(1): 146–160, https://doi.org/10.1007/s11430-022-1001-0