Detectable Anthropogenic Expansion of Compound Dry and Hot Event Areas on Global Land

Anthropogenic influence have led to an increase in the frequency of compound dry and hot events (CDHEs) globally under the background of global warming. However, there is limited research on the extent of anthropogenic influence on the spatial extent of CDHEs. Our analysis, focusing on the changes in the affected area of CDHEs across the global land during the warm season from 1961 to 2013, indicates an increasing trend in both hemispheres and six continents, with the most obviously increases observed in the Northern Hemisphere (15.8 %/53 yr), Asia (16 %/53 yr), and Africa (14 %/53 yr). Using the optimal fingerprinting method for detection and attribution analysis, we found that the anthropogenic signal was robustly detected in all regions except Oceania. The greenhouse gases emission played a major role in the observed increasing trends in all regions except Oceania. Furthermore, we conducted an event attribution analysis for the 2022–like CDHEs areas in the Northern Hemisphere, finding that nearly 95 %, 91 %, and 89 % of the trends in the Northern Hemisphere, Asia, and Europe, respectively, could be attributed to anthropogenic climate change. Using the attribution result, we constrained projections of spatial extent of CDHEs under the SSP2–4.5 and SSP5–8.5 emission scenarios. The constrained projections show a smaller increasing magnitude compared to the raw projections (except for Asia), with the largest differences observed in South America in the Southern Hemisphere. By 2100, the CDHEs areas in the Northern Hemisphere are projected to reach 43 % and 68 % under the SSP2–4.5 and SSP5–8.5 scenarios, respectively. Asia faces the most widespread impact from CHDEs, with more than 93 % under the SSP5–8.5 scenario and 56 % under the SSP2–4.5 scenario. Therefore, reducing greenhouse gas emissions has huge benefits for better mitigating the impacts of CDHEs across the global land.