aridification

{{Short description|Long-term process of a region becoming increasingly arid}}

{{use mdy dates|date=July 2023}}

{{More citations needed|date=November 2019}}

Aridification is the process of a region becoming increasingly arid, or dry. It refers to long term change,{{Cite journal|last1=Heidari|first1=Hadi|last2=Arabi|first2=Mazdak|last3=Warziniack|first3=Travis|last4=Kao|first4=Shih-Chieh|date=2020|title=Assessing Shifts in Regional Hydroclimatic Conditions of U.S. River Basins in Response to Climate Change over the 21st Century|journal=Earth's Future|language=en|volume=8|issue=10|pages=e2020EF001657|doi=10.1029/2020EF001657|bibcode=2020EaFut...801657H |issn=2328-4277|doi-access=free}} rather than seasonal variation.

It is often measured as the reduction of average soil moisture content.

It can be caused by reduced precipitation, increased evaporation, lowering of water tables, and changes in ground cover acting individually or in combination.

Its major consequences include reduced agricultural production, soil degradation, ecosystem changes and decreased water catchment runoff.{{Cite web |url=http://www.unescap.org/STAT/envstat/stwes-class-glasod.pdf |title=GLASOD Classification of Soil Degradation |date=February 2000 |website=United Nations ESCAP |archive-url=https://web.archive.org/web/20110607181427/http://www.unescap.org/STAT/envstat/stwes-class-glasod.pdf |archive-date=2011-06-07 |url-status=dead |access-date=2019-09-04}}

Some researchers have found that the Colorado River basin and other parts of western North America are currently undergoing aridification.{{cite news |work=University of Michigan |title=But it's a dry heat: Climate change and the aridification of North America |url=https://news.umich.edu/but-its-a-dry-heat-climate-change-and-the-aridification-of-north-america/ |first=Jim |last=Erickson |date=May 19, 2020 |access-date=September 7, 2022 }}{{cite journal |doi=10.1073/pnas.2006323117|title=Climate change and the aridification of North America |year=2020 |last1=Overpeck |first1=Jonathan T. |last2=Udall |first2=Bradley |journal=Proceedings of the National Academy of Sciences |volume=117 |issue=22 |pages=11856–11858 |pmid=32430321 |pmc=7275756 |bibcode=2020PNAS..11711856O |s2cid=218758593 |doi-access=free }}

A December 2024 report from the UNCCD concluded that more than three-quarters of the Earth's land "has become permanently dryer in recent decades", that "drier climates now affecting vast regions across the globe will not return to how they were", and that a quarter of the global population lives in expanding drylands.{{cite web |title=The Global Threat of Drying Lands: Regional and global aridity trends and future projections |url=https://www.unccd.int/sites/default/files/2024-12/aridity_report.pdf |publisher=United Nations Convention to Combat Desertification (UNCCD) |archive-url=https://web.archive.org/web/20241210223314/https://www.unccd.int/sites/default/files/2024-12/aridity_report.pdf |archive-date=10 December 2024 |page=7 (Forward) |date=9 December 2024 |url-status=live }}