1. Detectable Anthropogenic Intensification of the Summer Compound Hot and Dry Events Over Global Land Areas.
- Author
-
Pan, Rongyun, Li, Wei, Wang, Qirong, and Ailiyaer, Aihaiti
- Subjects
HOT weather conditions ,GLOBAL warming ,MARGINAL distributions ,GREENHOUSE gases - Abstract
Compound hot and dry events (CHDEs) pose an increasing threat to global warming and have received growing attention in recent decades. We conducted a detection and attribution analysis (D&A) using the optimal fingerprint technique to analyze the changes in observed CHDEs at continental and sub‐continental scales from 1961 to 2014. The responses of CHDEs changes to anthropogenic (ANT), greenhouse gases (GHG), aerosols (AER), and natural (NAT) forcings were obtained from the Coupled Model Intercomparison Project phase 6 forcing experiment. In a two‐signal D&A analysis that considered ANT and NAT simultaneously, ANT signals were robustly detected and separated from NAT in all continental domains and more than 65% of subcontinental domains (29 out of 44 domains). The trend attributed to the ANT forcing is comparable to the observed trend over domains where the ANT signal is detectable. We also conducted a three‐signal D&A analysis that regressed observation onto GHG, AER, and NAT simultaneously. The GHG signals were detectable in all continents except Oceania, and it contributed dominantly to the observed trend over 22 out of 29 regions where ANT signals had emerged. Multivariate biases correction can largely reduce the models' biases in simulating the marginal distribution and the dependence structure, which can provide a more accurate future risk of CDHEs. We found that limiting global warming to 1.5℃ rather than 2.0℃ can significantly mitigate the impact of compound events in most areas of global land, particularly in South America, Africa, and Oceania. Plain Language Summary: The severity of compound hot and dry events (CDHEs) is an important property of CDHEs, its changes can pose a great threat to agriculture production. Previous studies demonstrated that the anthropogenic influence has increased the probability of CDHEs over most regions across the globe by comparing observation with ALL forcing and natural‐forcing simulations. However, how much the long‐term trend in the severity of CDHEs is attributed to anthropogenic forcing is unsolved. We used the optimal fingerprint technology with the newly released models from Coupled Model Intercomparison Project phase 6 to quantify the contribution of different external forcing to the trend of the severity of CHDEs. The detectable anthropogenic signal has been found on six continents and more than 50% of sub‐continents. Greenhouse gases (GHG) are found to contribute dominantly to anthropogenic‐induced changes. Additional strict control regulations on GHG emissions are thus suggested to mitigate its impact on the intensification of CDHEs. Key Points: The anthropogenic influence on the intensified of compound hot and dry events on six continents and more than 65% of 44 sub‐continents have been robustly detectedAnthropogenic greenhouse gases dominantly contribute to the observed changes over the regions with anthropogenic signal detectableLimiting global warming to 1.5℃ can largely avoid the impact of compound events in most global land areas, especially over tropical regions [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF