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Human-induced changes in the distribution of rainfall

A likely consequence of global warming will be the redistribution of Earth’s rain belts, affecting water availability for many of Earth’s inhabitants. We consider three ways in which planetary warming might influence the global distribution of precipitation. The first possibility is that rainfall in...

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Detalles Bibliográficos
Autores principales: Putnam, Aaron E., Broecker, Wallace S.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Association for the Advancement of Science 2017
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5451196/
https://www.ncbi.nlm.nih.gov/pubmed/28580418
http://dx.doi.org/10.1126/sciadv.1600871
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author Putnam, Aaron E.
Broecker, Wallace S.
author_facet Putnam, Aaron E.
Broecker, Wallace S.
author_sort Putnam, Aaron E.
collection PubMed
description A likely consequence of global warming will be the redistribution of Earth’s rain belts, affecting water availability for many of Earth’s inhabitants. We consider three ways in which planetary warming might influence the global distribution of precipitation. The first possibility is that rainfall in the tropics will increase and that the subtropics and mid-latitudes will become more arid. A second possibility is that Earth’s thermal equator, around which the planet’s rain belts and dry zones are organized, will migrate northward. This northward shift will be a consequence of the Northern Hemisphere, with its large continental area, warming faster than the Southern Hemisphere, with its large oceanic area. A third possibility is that both of these scenarios will play out simultaneously. We review paleoclimate evidence suggesting that (i) the middle latitudes were wetter during the last glacial maximum, (ii) a northward shift of the thermal equator attended the abrupt Bølling-Allerød climatic transition ~14.6 thousand years ago, and (iii) a southward shift occurred during the more recent Little Ice Age. We also inspect trends in seasonal surface heating between the hemispheres over the past several decades. From these clues, we predict that there will be a seasonally dependent response in rainfall patterns to global warming. During boreal summer, in which the rate of recent warming has been relatively uniform between the hemispheres, wet areas will get wetter and dry regions will become drier. During boreal winter, rain belts and drylands will expand northward in response to differential heating between the hemispheres.
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spelling pubmed-54511962017-06-02 Human-induced changes in the distribution of rainfall Putnam, Aaron E. Broecker, Wallace S. Sci Adv Research Articles A likely consequence of global warming will be the redistribution of Earth’s rain belts, affecting water availability for many of Earth’s inhabitants. We consider three ways in which planetary warming might influence the global distribution of precipitation. The first possibility is that rainfall in the tropics will increase and that the subtropics and mid-latitudes will become more arid. A second possibility is that Earth’s thermal equator, around which the planet’s rain belts and dry zones are organized, will migrate northward. This northward shift will be a consequence of the Northern Hemisphere, with its large continental area, warming faster than the Southern Hemisphere, with its large oceanic area. A third possibility is that both of these scenarios will play out simultaneously. We review paleoclimate evidence suggesting that (i) the middle latitudes were wetter during the last glacial maximum, (ii) a northward shift of the thermal equator attended the abrupt Bølling-Allerød climatic transition ~14.6 thousand years ago, and (iii) a southward shift occurred during the more recent Little Ice Age. We also inspect trends in seasonal surface heating between the hemispheres over the past several decades. From these clues, we predict that there will be a seasonally dependent response in rainfall patterns to global warming. During boreal summer, in which the rate of recent warming has been relatively uniform between the hemispheres, wet areas will get wetter and dry regions will become drier. During boreal winter, rain belts and drylands will expand northward in response to differential heating between the hemispheres. American Association for the Advancement of Science 2017-05-31 /pmc/articles/PMC5451196/ /pubmed/28580418 http://dx.doi.org/10.1126/sciadv.1600871 Text en Copyright © 2017, The Authors http://creativecommons.org/licenses/by-nc/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license (http://creativecommons.org/licenses/by-nc/4.0/) , which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.
spellingShingle Research Articles
Putnam, Aaron E.
Broecker, Wallace S.
Human-induced changes in the distribution of rainfall
title Human-induced changes in the distribution of rainfall
title_full Human-induced changes in the distribution of rainfall
title_fullStr Human-induced changes in the distribution of rainfall
title_full_unstemmed Human-induced changes in the distribution of rainfall
title_short Human-induced changes in the distribution of rainfall
title_sort human-induced changes in the distribution of rainfall
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5451196/
https://www.ncbi.nlm.nih.gov/pubmed/28580418
http://dx.doi.org/10.1126/sciadv.1600871
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