Drivers, timing and some impacts of global aridity change

The modeled robustness of the aridity response to climate change has already been well established: global drylands are expanding as increases in potential evapotranspiration outpace precipitation increases. This work considers three questions not previously addressed: (1) in which aridity zones are...

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Main Authors: Lickley, Megan Jeramaz, Solomon, Susan
Other Authors: Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Format: Article
Published: IOP Publishing 2018
Online Access:http://hdl.handle.net/1721.1/119640
https://orcid.org/0000-0001-5810-8784
https://orcid.org/0000-0002-2020-7581
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author Lickley, Megan Jeramaz
Solomon, Susan
author2 Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
author_facet Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences
Lickley, Megan Jeramaz
Solomon, Susan
author_sort Lickley, Megan Jeramaz
collection MIT
description The modeled robustness of the aridity response to climate change has already been well established: global drylands are expanding as increases in potential evapotranspiration outpace precipitation increases. This work considers three questions not previously addressed: (1) in which aridity zones are aridity trends expected to first emerge? (2) To what extent are future populations expected to experience changes in aridity? (3) For which locations and populations is aridity change determined by changes in precipitation versus temperature? Using a multi-model ensemble of general circulation models (GCMs) from the CMIP5 archives, together with population statistics from United Nations databases we find the following: (1) drier regions are projected to dry earlier, more severely and to a greater extent than humid regions. (2) By the end of the century, up to 700 million more people are projected to live in arid regions, with half of humankind living in regions experiencing drying of at least 5% and 3 billion experiencing 25% drying under a high emissions scenario. The largest populations to experience extreme drying are in Africa and Asia. According to GCMs, aridity increases have already begun to emerge in Northern Africa. Populations in sub-Saharan Africa appear to be the most vulnerable considering current water scarcity levels there. And (3) precipitation change is projected to drive the most severe drying in arid regions, contributing to the earliest emerging signals of aridity change and driving the differential drying across aridity zones. A comparison of aridity data derived from observations with model ensemble data suggests that increased aridity is already emerging in the driest regions. In sum, widespread aridity trends across a warming state imply that most of humanity will live in a more arid world.
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spelling mit-1721.1/1196402022-10-01T17:58:48Z Drivers, timing and some impacts of global aridity change Lickley, Megan Jeramaz Solomon, Susan Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Lickley, Megan Jeramaz Solomon, Susan The modeled robustness of the aridity response to climate change has already been well established: global drylands are expanding as increases in potential evapotranspiration outpace precipitation increases. This work considers three questions not previously addressed: (1) in which aridity zones are aridity trends expected to first emerge? (2) To what extent are future populations expected to experience changes in aridity? (3) For which locations and populations is aridity change determined by changes in precipitation versus temperature? Using a multi-model ensemble of general circulation models (GCMs) from the CMIP5 archives, together with population statistics from United Nations databases we find the following: (1) drier regions are projected to dry earlier, more severely and to a greater extent than humid regions. (2) By the end of the century, up to 700 million more people are projected to live in arid regions, with half of humankind living in regions experiencing drying of at least 5% and 3 billion experiencing 25% drying under a high emissions scenario. The largest populations to experience extreme drying are in Africa and Asia. According to GCMs, aridity increases have already begun to emerge in Northern Africa. Populations in sub-Saharan Africa appear to be the most vulnerable considering current water scarcity levels there. And (3) precipitation change is projected to drive the most severe drying in arid regions, contributing to the earliest emerging signals of aridity change and driving the differential drying across aridity zones. A comparison of aridity data derived from observations with model ensemble data suggests that increased aridity is already emerging in the driest regions. In sum, widespread aridity trends across a warming state imply that most of humanity will live in a more arid world. Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences (Callahan-Dee Fellowship) 2018-12-13T19:01:32Z 2018-12-13T19:01:32Z 2018-10 2018-08 2018-12-06T18:37:29Z Article http://purl.org/eprint/type/JournalArticle 1748-9326 http://hdl.handle.net/1721.1/119640 Lickley, Megan, and Susan Solomon. “Drivers, Timing and Some Impacts of Global Aridity Change.” Environmental Research Letters 13, no. 10 (October 5, 2018): 104010. © 2018 The Authors https://orcid.org/0000-0001-5810-8784 https://orcid.org/0000-0002-2020-7581 http://dx.doi.org/10.1088/1748-9326/aae013 Environmental Research Letters Creative Commons Attribution 3.0 Unported license http://creativecommons.org/licenses/by/3.0/ application/pdf IOP Publishing IOP Publishing
spellingShingle Lickley, Megan Jeramaz
Solomon, Susan
Drivers, timing and some impacts of global aridity change
title Drivers, timing and some impacts of global aridity change
title_full Drivers, timing and some impacts of global aridity change
title_fullStr Drivers, timing and some impacts of global aridity change
title_full_unstemmed Drivers, timing and some impacts of global aridity change
title_short Drivers, timing and some impacts of global aridity change
title_sort drivers timing and some impacts of global aridity change
url http://hdl.handle.net/1721.1/119640
https://orcid.org/0000-0001-5810-8784
https://orcid.org/0000-0002-2020-7581
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