Editing Aridity (section)

== Change over time ==
{{Main|Aridification}}
The distribution of aridity at any time is largely the result of the general circulation of the [[atmosphere]]. The latter does change significantly over time through [[climate change]]. For example, temperature increase by 1.5–2.1 percent across the [[Nile Basin]] over the next 30–40 years could change the region from [[Semi-arid climate|semi-arid]] to arid, significantly reducing the land usable for [[agriculture]]. In addition, changes in land use can increase demands on soil water and thereby increase aridity.<ref>{{Cite web | title = Increasing Aridity and Land-use Overlap Have Potential to Cause Social and Economic Conflict in Dryland Areas | author = United States Geological Survey | author-link = United States Geological Survey | date = 24 May 2017| url = https://www.usgs.gov/news/national-news-release/increasing-aridity-and-land-use-overlap-have-potential-cause-social-and | access-date = 29 July 2022 }}</ref>

A December 2024 report from the [[United Nations Convention to Combat Desertification|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.<ref name=UNCCD_20241209>{{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 }}</ref>