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{{distinguish|NLRB election procedures#Decertification elections{{!}}Decertification|Desertion}}
{{Use dmy dates|date=February 2024}}
[[File:Global distribution of dryland subtypes based on the aridity index.png|upright=1.4|thumb|Global distribution of dryland subtypes based on the [[aridity index]] (
'''Desertification''' is a type of gradual [[land degradation]] of [[Soil fertility|fertile]] land into arid [[desert]] due to a combination of natural processes and human activities.<ref>{{Cite web |title=Desertification - an overview {{!}} ScienceDirect Topics |url=https://www.sciencedirect.com/topics/earth-and-planetary-sciences/desertification |access-date=2022-04-03 |website=www.sciencedirect.com |archive-date=2022-04-03 |archive-url=https://web.archive.org/web/20220403121044/https://www.sciencedirect.com/topics/earth-and-planetary-sciences/desertification |url-status=live }}</ref> This spread of arid areas is caused by a variety of factors, such as [[overexploitation]] of [[soil]] as a result of human activity and the [[effects of climate change]].<ref>{{cite web |title=Sustainable development of drylands and combating desertification |url=http://www.fao.org/docrep/v0265e/v0265e01.htm |url-status=live |archive-url=https://web.archive.org/web/20170804222104/http://www.fao.org/docrep/v0265e/v0265e01.htm |archive-date=4 August 2017 |access-date=21 June 2016}}</ref><ref name="Zeng L17401">{{Cite journal |last1=Zeng |first1=Ning |last2=Yoon |first2=Jinho |date=1 September 2009 |title=Expansion of the world's deserts due to vegetation-albedo feedback under global warming |journal=Geophysical Research Letters |volume=36 |issue=17 |page=L17401 |bibcode=2009GeoRL..3617401Z |doi=10.1029/2009GL039699 |issn=1944-8007 |s2cid=1708267 |doi-access=free}}</ref> Geographic areas most affected are located in Africa ([[Sahel]] region), Asia ([[Gobi Desert]] and [[Mongolia]]) and parts of [[South America]]. [[Drylands]] occupy approximately 40–41% of Earth's land area and are home to more than 2 billion people.<ref name=":5">[https://unemg.org/2018/images/emgdocs/publications/Global_Drylands_Full_Report.pdf Global Drylands Report] unemg.org 2018</ref> Effects of desertification include [[Sand storm|sand and dust storms]], [[Food security|food insecurity]], and [[poverty]].
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Desertification often causes rural lands to become unable to support the same sized populations that previously lived there. This results in mass [[human migration|migrations]] out of rural areas and into urban areas particularly in Africa creating unemployment and [[slum]]s.<ref>{{cite book|author=Pasternak, Dov|author2=Schlissel, Arnold|title=Combating desertification with plants|publisher=Springer|year=2001|isbn=978-0-306-46632-8|page=20|url=https://books.google.com/books?id=B-i8-DPf6xgC&pg=PA20|access-date=2016-05-16|archive-date=2023-07-30|archive-url=https://web.archive.org/web/20230730161050/https://books.google.com/books?id=B-i8-DPf6xgC&pg=PA20|url-status=live}}</ref><ref>{{cite book|author=Briassoulis, Helen|title=Policy integration for complex environmental problems: the example of Mediterranean desertification|publisher=Ashgate Publishing|year=2005|isbn=978-0-7546-4243-5|page=161|url=https://books.google.com/books?id=CpYnV45hVRsC&pg=PA161|access-date=2016-05-16|archive-date=2023-07-30|archive-url=https://web.archive.org/web/20230730161052/https://books.google.com/books?id=CpYnV45hVRsC&pg=PA161|url-status=live}}</ref> The number of these [[Environmental migrant|environmental refugees]] grows every year, with projections for sub-Saharan Africa showing a probable increase from 14 million in 2010 to nearly 200 million by 2050. This presents a future crisis for the region, as neighboring nations do not always have the ability to support large populations of refugees.<ref>{{cite journal |last1=Myers |first1=Norman |date=29 April 2002 |title=Environmental refugees: a growing phenomenon of the 21st century |journal=Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences |volume=357 |issue=1420 |pages=609–613 |doi=10.1098/rstb.2001.0953 |pmc=1692964 |pmid=12028796}}</ref><ref>{{cite journal |last1=Epule |first1=Terence Epule |last2=Peng |first2=Changhui |last3=Lepage |first3=Laurent |date=5 February 2014 |title=Environmental refugees in sub-Saharan Africa: a review of perspectives on the trends, causes, challenges and way forward |journal=GeoJournal |volume=80 |pages=79–92 |doi=10.1007/s10708-014-9528-z |s2cid=154503204}}</ref>
In [[Mongolia]], the land is 90% fragile dry land, which causes many herders to migrate to the city for work. With very limited resources, the herders that stay on the dry land graze very carefully in order to preserve the land.<ref>{{Cite web |date=2018-08-01 |title=Mongolia's nomadic way of life under threat |url=https://gulfnews.com/lifestyle/mongolias-nomadic-way-of-life-under-threat-1.2259998 |access-date=2023-10-04 |website=gulfnews.com |language=en}}</ref>
Agriculture is a main source of income for many desert communities. The increase in desertification in these regions has degraded the land to such an extent where people can no longer productively farm and make a profit. This has negatively impacted the economy and increased poverty rates.<ref>{{Cite journal|last1=Stringer|first1=Lindsay C.|last2=Dyer|first2=Jen C.|last3=Reed|first3=Mark S.|last4=Dougill|first4=Andrew J.|last5=Twyman|first5=Chasca|last6=Mkwambisi|first6=David|title=Adaptations to climate change, drought and desertification: local insights to enhance policy in southern Africa|journal=Environmental Science & Policy|volume=12|issue=7|pages=748–765|doi=10.1016/j.envsci.2009.04.002|year=2009|bibcode=2009ESPol..12..748S }}</ref>
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==Geographic areas affected==
[[Drylands]] occupy approximately 40–41% of Earth's land area and are home to more than 2
===Sahel===
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[[Lake Chad]], located in the Sahel region, has undergone desiccation due to water withdrawal for irrigation and decrease in rainfall.<ref>{{cite journal |last1=Okpara |first1=Uche T. |last2=Stringer |first2=Lindsay C. |last3=Dougill |first3=Andrew J. |date=November 2016 |title=Lake drying and livelihood dynamics in Lake Chad: Unravelling the mechanisms, contexts and responses |journal=Ambio |volume=45 |issue=7 |pages=781–795 |bibcode=2016Ambio..45..781O |doi=10.1007/s13280-016-0805-6 |pmc=5055484 |pmid=27371137}}</ref> The lake has shrunk by over 90% since 1987, displacing millions of inhabitants.<ref>{{Cite web |last=Jiang |first=Ingrid |date=2022-08-12 |title=A Remarkable Size Shrinking in Lake Chad |url=https://storymaps.arcgis.com/stories/e63a90f8552d4e5f98f4c56a56c06f9d |access-date=2023-09-22 |website=ArcGIS StoryMaps |language=en-ca}}</ref> Recent efforts have managed to make some progress toward its restoration, but it is still considered to be at risk of disappearing entirely.<ref name="Remote sensing appraisal of Lake Ch">{{cite journal |last1=Onamuti |first1=Olapeju Y. |last2=Okogbue |first2=Emmanuel C. |last3=Orimoloye |first3=Israel R. |date=8 November 2017 |title=Remote sensing appraisal of Lake Chad shrinkage connotes severe impacts on green economics and socio-economics of the catchment area |journal=Royal Society Open Science |volume=4 |issue=11 |pages=171120 |doi=10.1098/rsos.171120 |pmc=5717671 |pmid=29291097}}</ref>
To limit desertification, the [[Great Green Wall (Africa)]] initiative was started in 2007 involving the planting of vegetation along a stretch of 7,775
===Gobi Desert and Mongolia===
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===South America===
[[South America]] is another area vulnerable by desertification, as 25% of the land is classified as drylands<ref>{{Cite web |date=16 June 2016 |title=Soil Degradation Threatens Nutrition in Latin America - World |url=https://reliefweb.int/report/world/soil-degradation-threatens-nutrition-latin-america |url-status=live |archive-url=https://web.archive.org/web/20220403121753/https://reliefweb.int/report/world/soil-degradation-threatens-nutrition-latin-america |archive-date=2022-04-03 |access-date=2022-04-03 |website=ReliefWeb |language=en}}</ref> and over 68% of the land area has undergone soil erosion as a result of deforestation and overgrazing.<ref name=":0">{{Cite web |date=2018-06-15 |title=Why We Should Invest in Land Management in Latin America |url=https://www.nrdc.org/bio/carolina-herrera/why-we-should-invest-land-management-latin-america |access-date=2023-09-25 |website=www.nrdc.org |language=en}}</ref> 27 to 43% of the land areas in Bolivia, Chile, Ecuador and Peru are at risk due to desertification. In Argentina, Mexico and Paraguay, greater than half the land area is degraded by desertification and cannot be used for agriculture. In Central America, drought has caused increased unemployment and decreased food security - also causing migration of people. Similar impacts have been seen in rural parts of Mexico where about 1,000
==Reversing desertification{{anchor|Countermeasures_and_prevention}}==
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===Better managed grazing===
Restored grasslands store CO<sub>2</sub> from the atmosphere as organic plant material. [[Grazing]] livestock, usually not left to wander, consume the grass and minimize its growth.<ref name="Tlovell">{{cite news|url=http://www.newstatesman.com/environment/2011/01/lovell-carbon-ward-climate|title=How fences could save the planet|publisher=newstatesman.com|access-date=May 5, 2013|date=January 13, 2011|archive-date=August 14, 2017|archive-url=https://web.archive.org/web/20170814221316/http://www.newstatesman.com/environment/2011/01/lovell-carbon-ward-climate|url-status=live}}</ref> A method proposed to restore grasslands uses fences with many small paddocks, moving herds from one paddock to another after a day or two in order to mimic natural grazers and allowing the grass to grow optimally.<ref name="Tlovell" /><ref>{{cite news|url=http://news.mongabay.com/2008/0221-soil_carbon_lovell_interview.html|title=Restoring soil carbon can reverse global warming, desertification and biodiversity|publisher=mongabay.com|access-date=May 5, 2013|date=February 21, 2008|url-status=dead|archive-url=https://archive.today/20130625040133/http://news.mongabay.com/2008/0221-soil_carbon_lovell_interview.html|archive-date=June 25, 2013}}</ref><ref>{{cite news|url=http://www.time.com/time/magazine/article/0,9171,1953692,00.html|archive-url=https://web.archive.org/web/20100117215802/http://www.time.com/time/magazine/article/0,9171,1953692,00.html|url-status=dead|archive-date=January 17, 2010|title=How eating grass-fed beef could help fight climate change|publisher=time.com|access-date=May 11, 2013|date=January 25, 2010|first=Lisa|last=Abend}}</ref> Proponents of managed grazing methods estimate that increasing this method could increase carbon content of the soils in the world's 3.5
=== Planting trees ===
{{Main|Reforestation|Afforestation}}
[[Reforestation]] gets at one of the root causes of desertification and is not just a treatment of the symptoms. Environmental organizations work in places where deforestation and desertification are contributing to extreme [[poverty]]. There they focus primarily on educating the local population about the dangers of deforestation and sometimes employ them to grow seedlings, which they transfer to severely deforested areas during the rainy season.<ref>{{cite web |date=1997 |title=Desertification |url=http://pubs.usgs.gov/gip/deserts/desertification/ |url-status=live |archive-url=https://web.archive.org/web/20100802200740/http://pubs.usgs.gov/gip/deserts/desertification/ |archive-date=2010-08-02 |access-date=2006-06-10 |website=USGS}}</ref> The [[Food and Agriculture Organization of the United Nations]] launched the FAO Drylands Restoration Initiative in 2012 to draw together knowledge and experience on dryland restoration.<ref>{{cite web |title=Drylands Restoration Initiative |url=http://www.fao.org/forestry/aridzone/restoration/en/ |url-status=live |archive-url=https://web.archive.org/web/20160723220152/http://www.fao.org/forestry/aridzone/restoration/en/ |archive-date=23 July 2016 |access-date=14 April 2016 |publisher=Food and Agriculture Organization of the United Nations}}</ref>
The "[[Green Wall of China]]" is a high-profile example of one method that has been finding success in this battle with desertification.<ref>{{Cite web |title=desertification 3D environment |url=https://b2b.partcommunity.com/community/knowledge/en/detail/9815/Desertification#knowledge_article |url-status=live |archive-url=https://web.archive.org/web/20210228141238/https://b2b.partcommunity.com/community/knowledge/en/detail/9815/Desertification#knowledge_article |archive-date=2021-02-28 |access-date=2020-09-25}}</ref> This wall is a much larger-scale version of what American farmers did in the 1930s to stop the great Midwest dust bowl. This plan was proposed in the late 1970s, and has become a major ecological engineering project that is not predicted to end until the year 2055. According to Chinese reports, there have been nearly 66 billion trees planted in China's great green wall.<ref>{{Cite web |date=2017-04-21 |title=China's 'Great Green Wall' Fights Expanding Desert |url=http://news.nationalgeographic.com/2017/04/china-great-green-wall-gobi-tengger-desertification/ |url-status=dead |archive-url=https://web.archive.org/web/20170813110737/http://news.nationalgeographic.com/2017/04/china-great-green-wall-gobi-tengger-desertification/ |archive-date=2017-08-13 |access-date=2017-05-04}}</ref> The green wall of China has decreased desert land in China by an annual average of 1,980 square km.<ref>{{Cite news |last=Hui |first=Lu |date=May 26, 2018 |title=Across China: A guardian of the great green wall against China's second largest desert |url=http://www.xinhuanet.com/english/2018-05/26/c_137207841.htm |url-status=dead |archive-url=https://web.archive.org/web/20180526094225/http://www.xinhuanet.com/english/2018-05/26/c_137207841.htm |archive-date=May 26, 2018 |work=Xinghua News Agency}}</ref> The frequency of sandstorms nationwide have fallen 20% due to the green wall.<ref>{{Cite journal |last=Beiser |first=Vince |date=September 1, 2017 |title=A tree grows in China: can a "Green Great Wall" stop sand from devouring the countryside? |journal=Mother Jones |volume=83 |issue=4}}</ref> Due to the success that China has been finding in stopping the spread of desertification, plans are currently being made in Africa to start a "wall" along the borders of the Sahara desert as well to be financed by the United Nations Global Environment Facility trust.<ref>{{Cite journal |last=Gadzama |first=Njidda Mamadu |date=2017 |title=Attenuation of the effects of desertification through sustainable development of Great Green Wall in the Sahel of Africa |journal=World Journal of Science, Technology and Sustainable Development |volume=14 |issue=4 |pages=279–289 |doi=10.1108/WJSTSD-02-2016-0021}}</ref>
[[File:Great green wall map.svg|thumb|The [[Great Green Wall (Africa)|Great Green Wall]], participating countries and Sahel. In September 2020, it was reported that the GGW had covered only 4% of the planned area.<ref>{{cite news |author=Jonathan Watts |date=7 September 2020 |title=Africa's Great Green Wall just 4% complete halfway through schedule |url=https://www.theguardian.com/environment/2020/sep/07/africa-great-green-wall-just-4-complete-over-halfway-through-schedule |url-status=live |archive-url=https://web.archive.org/web/20220506222825/https://www.theguardian.com/environment/2020/sep/07/africa-great-green-wall-just-4-complete-over-halfway-through-schedule |archive-date=6 May 2022 |access-date=18 December 2021 |newspaper=The Guardian |via=www.theguardian.com |issn=0261-3077}}</ref>]]
In 2007 the [[African Union]] started the [[Great Green Wall (Africa)|Great Green Wall of Africa]] project in order to combat desertification in 20 countries.<ref>{{Cite web |title=Great Green Wall{{!}}Action Against Desertification{{!}}Food and Agriculture Organization of the United Nations |url=https://www.fao.org/in-action/action-against-desertification/overview/great-green-wall/en/ |url-status=live |archive-url=https://web.archive.org/web/20220127153831/https://www.fao.org/in-action/action-against-desertification/overview/great-green-wall/en/ |archive-date=2022-01-27 |access-date=2022-02-27 |website=www.fao.org}}</ref> The wall is 8,000 km wide, stretching across the entire width of the continent and has 8 billion dollars in support of the project. The project has restored 36{{nbsp}}million{{nbsp}}hectares of land, and by 2030 the initiative plans to restore a total of 100
== History ==
{{Further|Historic desertification}}
The world's most noted [[deserts]] have been
Historical evidence shows that the serious and extensive land deterioration occurring several centuries ago in arid regions had three centers: the Mediterranean, the Mesopotamian Valley, and the [[Loess Plateau]] of China, where population was dense.<ref name=":7">{{cite web |last=Dregne |first=H.E. |title=Desertification of Arid Lands |url=http://www.ciesin.columbia.edu/docs/002-193/002-193.html |url-status=live |archive-url=https://web.archive.org/web/20230428120939/http://www.ciesin.columbia.edu/docs/002-193/002-193.html |archive-date=28 April 2023 |access-date=3 December 2013 |publisher=Columbia University}}</ref>
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