Post-2000 greening of Kalahari Desert and southern African grasslands reduces food and economic insecurity in Africa
The Kalahari high-pressure system that forms the Kalahari and Namib Deserts of Southern Africa is maintained by the sinking motion of the Hadley circulation. Despite projected desertification under the climate change, beginning in the early 21st century the Kalahari Desert and grasslands of South Af...
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| Format: | Article |
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IOP Publishing
2025-01-01
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| Series: | Environmental Research Letters |
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| Online Access: | https://doi.org/10.1088/1748-9326/adf23a |
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| author | Debashis Nath Reshmita Nath Wen Chen Wenju Cai Zizhen Dong Ruowen Yang |
| author_facet | Debashis Nath Reshmita Nath Wen Chen Wenju Cai Zizhen Dong Ruowen Yang |
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| description | The Kalahari high-pressure system that forms the Kalahari and Namib Deserts of Southern Africa is maintained by the sinking motion of the Hadley circulation. Despite projected desertification under the climate change, beginning in the early 21st century the Kalahari Desert and grasslands of South Africa, Lesotho–Drakensberg highland and Eswatini has experienced a trend of greening/Savannisation. Here, we find that the disparity is likely due to strong multidecadal variability. A positive phase of the Atlantic multidecadal oscillation during this period has intensified the Hadley circulation and widened the Kalahari anticyclone, thereby facilitating moisture transport from the warm Angola–Benguela front to southern African landmasses. The advected moisture brought wetness at its periphery, which satisfied the water demand for cropland expansion (∼10%–15%) in southern Africa. A water-food-economy nexus is increasing Africa’s crop yields by approximately 25%, reducing food and economic insecurity through a nearly fourfold increase in agricultural exports and contributing approximately 26% to the continent’s total agricultural output. However, in the opposite phase of multidecadal variability, the superposition of greenhouse warming would exacerbate the drying trend that will amplify aridity. |
| format | Article |
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| institution | Matheson Library |
| issn | 1748-9326 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | IOP Publishing |
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| series | Environmental Research Letters |
| spelling | doaj-art-aad19e65d75b4e45837d5e4de7cb66d12025-08-01T09:29:21ZengIOP PublishingEnvironmental Research Letters1748-93262025-01-0120909401210.1088/1748-9326/adf23aPost-2000 greening of Kalahari Desert and southern African grasslands reduces food and economic insecurity in AfricaDebashis Nath0https://orcid.org/0000-0001-9299-2729Reshmita Nath1Wen Chen2Wenju Cai3Zizhen Dong4https://orcid.org/0000-0003-0354-0208Ruowen Yang5https://orcid.org/0000-0002-8373-3669Yunnan International Joint Laboratory of Monsoon and Extreme Climate Disasters, Yunnan University , Kunming 650500, People’s Republic of China; State Key Laboratory of Vegetation Structure, Function and Construction (VegLab)/Yunnan Key Laboratory of Meteorological Disasters and Climate Resources in the Greater Mekong Subregion, Yunnan University , Kunming 650500, People’s Republic of China; Southwest United Graduate School , Kunming 650092, People’s Republic of ChinaKing Abdullah University of Science and Technology (KAUST) , Thuwal, Saudi ArabiaYunnan International Joint Laboratory of Monsoon and Extreme Climate Disasters, Yunnan University , Kunming 650500, People’s Republic of China; Southwest United Graduate School , Kunming 650092, People’s Republic of ChinaPhysical Oceanography Laboratory , Qingdao, People’s Republic of China; Frontiers Science Center for Deep Ocean Multispheres and Earth System , Qingdao, People’s Republic of China; Sanya Oceanographic Institution, Ocean University of China , Qingdao, People’s Republic of ChinaYunnan International Joint Laboratory of Monsoon and Extreme Climate Disasters, Yunnan University , Kunming 650500, People’s Republic of China; State Key Laboratory of Vegetation Structure, Function and Construction (VegLab)/Yunnan Key Laboratory of Meteorological Disasters and Climate Resources in the Greater Mekong Subregion, Yunnan University , Kunming 650500, People’s Republic of China; Southwest United Graduate School , Kunming 650092, People’s Republic of ChinaYunnan International Joint Laboratory of Monsoon and Extreme Climate Disasters, Yunnan University , Kunming 650500, People’s Republic of China; State Key Laboratory of Vegetation Structure, Function and Construction (VegLab)/Yunnan Key Laboratory of Meteorological Disasters and Climate Resources in the Greater Mekong Subregion, Yunnan University , Kunming 650500, People’s Republic of China; Southwest United Graduate School , Kunming 650092, People’s Republic of ChinaThe Kalahari high-pressure system that forms the Kalahari and Namib Deserts of Southern Africa is maintained by the sinking motion of the Hadley circulation. Despite projected desertification under the climate change, beginning in the early 21st century the Kalahari Desert and grasslands of South Africa, Lesotho–Drakensberg highland and Eswatini has experienced a trend of greening/Savannisation. Here, we find that the disparity is likely due to strong multidecadal variability. A positive phase of the Atlantic multidecadal oscillation during this period has intensified the Hadley circulation and widened the Kalahari anticyclone, thereby facilitating moisture transport from the warm Angola–Benguela front to southern African landmasses. The advected moisture brought wetness at its periphery, which satisfied the water demand for cropland expansion (∼10%–15%) in southern Africa. A water-food-economy nexus is increasing Africa’s crop yields by approximately 25%, reducing food and economic insecurity through a nearly fourfold increase in agricultural exports and contributing approximately 26% to the continent’s total agricultural output. However, in the opposite phase of multidecadal variability, the superposition of greenhouse warming would exacerbate the drying trend that will amplify aridity.https://doi.org/10.1088/1748-9326/adf23aKalahari desert and GrasslandsSouthern Africawetting and greeningHadley circulation and atmospheric processesfood securityeconomic security |
| spellingShingle | Debashis Nath Reshmita Nath Wen Chen Wenju Cai Zizhen Dong Ruowen Yang Post-2000 greening of Kalahari Desert and southern African grasslands reduces food and economic insecurity in Africa Environmental Research Letters Kalahari desert and Grasslands Southern Africa wetting and greening Hadley circulation and atmospheric processes food security economic security |
| title | Post-2000 greening of Kalahari Desert and southern African grasslands reduces food and economic insecurity in Africa |
| title_full | Post-2000 greening of Kalahari Desert and southern African grasslands reduces food and economic insecurity in Africa |
| title_fullStr | Post-2000 greening of Kalahari Desert and southern African grasslands reduces food and economic insecurity in Africa |
| title_full_unstemmed | Post-2000 greening of Kalahari Desert and southern African grasslands reduces food and economic insecurity in Africa |
| title_short | Post-2000 greening of Kalahari Desert and southern African grasslands reduces food and economic insecurity in Africa |
| title_sort | post 2000 greening of kalahari desert and southern african grasslands reduces food and economic insecurity in africa |
| topic | Kalahari desert and Grasslands Southern Africa wetting and greening Hadley circulation and atmospheric processes food security economic security |
| url | https://doi.org/10.1088/1748-9326/adf23a |
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