Sahara

{{short description|Desert on the African continent}} {{other uses}} {{pp-vandalism|small=yes}} {{Use dmy dates|date=April 2025}} {{Infobox valley | name = Sahara | native_name = {{unbulleted list|{{langx|ar|الصحراء الكبرى}}|{{transliteration|ar|ALA|aṣ-ṣaḥrā' al-kubrá}}|"The greatest desert"}} | photo = Sahara real color.jpg | photo_caption = The Sahara taken by Apollo 17 astronauts, 1972 | map_image = Sahara.svg | map_caption = Geographical map of the Sahara | location = | country = {{Flag|Algeria}} | country1 = {{Flag|Chad}} | country2 = {{Flag|Egypt}} | country3 = {{Flag|Libya}} | country4 = {{Flag|Mali}} | country5 = {{Flag|Mauritania}} | country6 = {{Flag|Morocco}} | country7 = {{Flag|Niger}} | country8 = {{Flag|Sudan}} | country9 = {{Flag|Tunisia}} | country10 = {{flag|Sahrawi Arab Democratic Republic}} | region = | state = | district = | city = | relief = | label = | label_position = | coordinates = {{Coord | 23 | 13 | type:landmark_source:googlemaps_scale:30000000 | display= title,inline}} | coordinates_ref =  | elevation = | elevation_m = | elevation_ft = | elevation_ref = | length = | length_mi = | length_km = 4,800 | length_orientation = | length_note = | width = | width_mi = | width_km = 1,800 | width_orientation = | width_note = | area = | area_mi2 = | area_km2 = 9,200,000 | depth = | depth_ft = | depth_m = | type = | age = | border = | topo = | traversed = | river = |footnotes = '''Population'''{{space|5}}2,500,000<ref name=brit/>  |map_size= }} The '''Sahara''' ({{IPAc-en|s|ə|ˈ|h|ɑːr|ə}}, {{IPAc-en|s|ə|ˈ|h|ɛ|r|ə}}) is a desert spanning North Africa. With an area of {{convert|9200000|km2}}, it is the largest hot desert in the world and the third-largest desert overall, smaller only than the deserts of Antarctica and the northern Arctic.<ref>{{cite journal|last1=Cook|first1=Kerry H.|last2=Vizy|first2=Edward K.|title=Detection and Analysis of an Amplified Warming of the Sahara Desert|journal=Journal of Climate|date=2015|volume=28|issue=16|page=6560|doi=10.1175/JCLI-D-14-00230.1|bibcode=2015JCli...28.6560C|doi-access=free}}</ref><ref name="geology.com">{{cite web|url=http://geology.com/records/largest-desert.shtml|title=Largest Desert in the World|access-date=30 December 2011|archive-date=17 August 2007|archive-url=https://web.archive.org/web/20070817025305/http://geology.com/records/largest-desert.shtml|url-status=live}}</ref><ref name="Size and Population of Sahara">{{cite web |title=Is the World Full or Empty? |url=http://storymaps.esri.com/stories/2013/full-and-empty/ |website=Story Maps |access-date=19 October 2018 |archive-date=15 January 2022 |archive-url=https://web.archive.org/web/20220115093724/https://storymaps.arcgis.com/stories/b4380439bc8c4293b36a4f9772c665ba |url-status=live }}</ref>

The name "Sahara" is derived from {{langx|ar|صَحَارَى|ṣaḥārā}} {{IPAc-ar|//|S|a|H|aa|r|aa}}, a broken plural form of {{transliteration|ar|ALA|ṣaḥrā'}} ({{lang|ar|صَحْرَاء}} {{IPAc-ar|//|S|a|H|r|aa|2}}), meaning "desert".<ref>{{OEtymD|Sahara|accessdate=25 June 2007}} {{Webarchive|url=https://web.archive.org/web/20090211112704/http://www.etymonline.com/index.php?term=Sahara |date=11 February 2009 }}</ref><ref>{{cite web |url=http://online.ectaco.co.uk/main.jsp?do=e-services-dictionaries-word_translate1&status=translate&lang1=23&lang2=ar&source_id=2119140 |title=English-Arabic online dictionary |publisher=ECTACO |date=28 December 2006 |access-date=12 June 2010 |archive-date=9 March 2009 |archive-url=https://web.archive.org/web/20090309105446/http://online.ectaco.co.uk/main.jsp?do=e-services-dictionaries-word_translate1&status=translate&lang1=23&lang2=ar&source_id=2119140 |url-status=live }}</ref><ref>{{cite book|last=Wehr|first=Hans|title=A Dictionary of Modern Written Arabic (Arabic-English)|year=1994|publisher=Otto Harrassowitz|location=Wiesbaden|isbn=978-0-87950-003-0|edition=4th|author-link=Hans Wehr|page=589}}</ref><ref>{{cite book|last=al-Ba'labakkī|first=Rūḥī|title=al-Mawrid: Qāmūs 'Arabī-Inklīzī|year=2002|publisher=Dār al-'Ilm lil-Malāyīn|location=Beirut|edition=16th|page=689|language=ar}}</ref>

The desert covers much of North Africa, excluding the fertile region on the Mediterranean Sea coast, the Atlas Mountains of the Maghreb, and the Nile Valley in Egypt and the Sudan.<ref name='brit'>{{Cite encyclopedia |title=Sahara |url=https://www.britannica.com/place/Sahara-desert-Africa |access-date=16 April 2023 |encyclopedia=Encyclopedia Britannica |last1=Gritzner |first1=Jeffrey Allman |last2=Peel |first2=Ronald Francis |language=en |archive-date=16 April 2023 |archive-url=https://web.archive.org/web/20230416134003/https://www.britannica.com/place/Sahara-desert-Africa |url-status=live }}</ref>

It stretches from the Red Sea in the east and the Mediterranean in the north to the Atlantic Ocean in the west, where the landscape gradually changes from desert to coastal plains. To the south it is bounded by the Sahel, a belt of semi-arid tropical savanna around the Niger River valley and the Sudan region of sub-Saharan Africa. The Sahara can be divided into several regions, including the western Sahara, the central Ahaggar Mountains, the Tibesti Mountains, the Aïr Mountains, the Ténéré desert, and the Libyan Desert.

For several hundred thousand years, the Sahara has alternated between desert and savanna grassland in a 20,000-year cycle<ref>{{cite news |last=Chu |first=Jennifer |title=A "pacemaker" for North African climate |url=http://news.mit.edu/2019/study-regulating-north-african-climate-0102 |publisher=MIT News |date=2 January 2019 |access-date=20 January 2020 |archive-date=15 January 2022 |archive-url=https://web.archive.org/web/20220115093627/https://news.mit.edu/2019/study-regulating-north-african-climate-0102 |url-status=live }}</ref> caused by the precession of Earth's axis (about 26,000 years) as it rotates around the Sun, which changes the location of the North African monsoon.

==Geography== thumb|upright=1.3|The main biomes in Africa [[File:Sahara satellite hires.jpg|thumb|A 2002 satellite image of the Sahara by NASA WorldWind]] The Sahara covers large parts of Algeria, Chad, Egypt, Libya, Mali, Mauritania, Niger, Western Sahara and Sudan, and parts of southern Morocco and Tunisia. It covers {{convert|9|e6km2|sqmi}}, 31% of the African continent. If all areas with a mean annual precipitation of less than {{Convert|250|mm|in|abbr=on}} were included, the Sahara would be {{convert|11|e6km2|sqmi}}. It is one of three distinct physiographic provinces of the African massive physiographic division. The Sahara is so large and bright that, in theory, it could be detected from other stars as a surface feature of Earth, with near-current technology.<ref>{{cite journal |last1=Farr |first1=Ben |last2=Farr |first2=Will M. |last3=Cowan |first3=Nicolas B. |last4=Haggard |first4=Hal M. |last5=Robinson |first5=Tyler |title=Exocartographer: A Bayesian Framework for Mapping Exoplanets in Reflected Light |journal=The Astronomical Journal |date=2018 |volume=156 |issue=4 |page=146 |doi=10.3847/1538-3881/aad775 |doi-access=free |arxiv=1802.06805 |bibcode=2018AJ....156..146F }}</ref>

The Sahara is a highly diverse desert region composed of hamada (rocky plateaus), ergs (sand seas covered with sand dunes), gravel plains (''reg''), dry valleys (''wadi''), dry lakes, and salt flats (''shatt'' or ''chott'').<ref name=PA1327>{{WWF ecoregion|id=pa1327|name=Sahara desert|access-date=30 December 2007}}</ref> Many of its sand dunes rise over {{convert|180|m}},<ref>Strahler, Arthur N. and Strahler, Alan H. (1987) ''Modern Physical Geography'' Third Edition. New York: John Wiley & Sons. {{ISBN|0-471-85064-0}}. p. 347</ref> and its landscapes are shaped by wind and rare rainfall. The region also includes mountain massifs, volcanic uplands, oases, and unusual landforms such as the Richat Structure in Mauritania.

Several deeply dissected mountains, many volcanic, rise from the desert, including the Aïr Mountains, Ahaggar Mountains, Saharan Atlas, Tibesti Mountains, Adrar des Iforas, and the Red Sea Hills. The highest peak in the Sahara is Emi Koussi, a shield volcano in the Tibesti range of northern Chad.

The central Sahara is hyperarid, with sparse vegetation. The northern and southern reaches of the desert, along with the highlands, have areas of sparse grassland and desert shrub, with trees and taller shrubs in wadis, where moisture collects. In the central, hyperarid region, there are many subdivisions: Tanezrouft, the Ténéré, the Libyan Desert, the Eastern Desert, the Nubian Desert and others. These extremely arid areas often receive no rain for years.

To the north, the Sahara skirts the Mediterranean Sea in Egypt and portions of Libya, but in Cyrenaica and the Maghreb, the Sahara borders the Mediterranean forest, woodland, and scrub eco-regions of northern Africa, all of which have a Mediterranean climate characterized by hot summers and cool and rainy winters. According to the botanical criteria of Frank White<ref>Wickens, Gerald E. (1998) ''Ecophysiology of Economic Plants in Arid and Semi-Arid Lands''. Springer, Berlin. {{ISBN|978-3-540-52171-6}}</ref> and geographer Robert Capot-Rey,<ref name=Grove1958>{{cite journal|author=Grove, A.T.|author2= Nicole|orig-date=1958|year=2007|title=The Ancient Erg of Hausaland, and Similar Formations on the South Side of the Sahara|journal=The Geographical Journal|volume=124|issue=4|pages=528–533|doi=10.2307/1790942|jstor=1790942}}</ref><ref name=Bisson2003>{{cite book|author=Bisson, J.|year=2003|title=Mythes et réalités d'un désert convoité: le Sahara|publisher=L'Harmattan|language=fr}}</ref> the northern limit of the Sahara corresponds to the northern limit of date palm cultivation and the southern limit of the range of esparto, a grass typical of the Mediterranean climate portion of the Maghreb and Iberia. The northern limit also corresponds to the {{convert|100|mm|in|abbr=on}} isohyet of annual precipitation.<ref name=Walton2007>{{cite book|author=Walton, K.|year=2007|title=The Arid Zones|publisher=Aldine|asin=B008MR69VM}}</ref>

To the south, the Sahara is bounded by the Sahel, a belt of dry tropical savanna with a summer rainy season that extends across Africa from east to west. The southern limit of the Sahara is indicated botanically by the southern limit of ''Cornulaca monacantha'' (a drought-tolerant member of the Chenopodiaceae), or northern limit of ''Cenchrus biflorus'', a grass typical of the Sahel.<ref name="Grove1958" /><ref name="Bisson2003" /> According to climatic criteria, the southern limit of the Sahara corresponds to the {{convert|150|mm|in|abbr=on}} isohyet of annual precipitation (this is a long-term average, since precipitation varies annually).<ref name="Walton2007" />

Important cities located in the Sahara include Nouakchott, the capital of Mauritania; Tamanrasset, Ouargla, Béchar, Hassi Messaoud, Ghardaïa, and El Oued in Algeria; Timbuktu in Mali; Agadez in Niger; Ghat in Libya; and Faya-Largeau in Chad.

==Climate== [[File:Hoggar8.jpg|thumb|An oasis in the Ahaggar Mountains. Oases support some life forms in extremely arid deserts.]] The Sahara is the world's largest hot desert.<ref>{{cite web|date=13 October 2020|title=The 10 Largest Deserts In The World|url=https://www.worldatlas.com/articles/10-largest-deserts-in-the-world.html|access-date=18 January 2022|website=WorldAtlas|language=en-US|archive-date=19 December 2021|archive-url=https://web.archive.org/web/20211219130419/https://www.worldatlas.com/articles/10-largest-deserts-in-the-world.html|url-status=live}}</ref><ref>{{Cite web |last=WPS |title=Interesting Facts About the Sahara Desert |url=https://www.globaladventurechallenges.com/journal/facts-about-sahara-desert |access-date=16 April 2023 |website=www.globaladventurechallenges.com |archive-date=16 April 2023 |archive-url=https://web.archive.org/web/20230416131547/https://www.globaladventurechallenges.com/journal/facts-about-sahara-desert |url-status=live }}</ref> It is located in the horse latitudes under the subtropical ridge, a significant belt of semi-permanent subtropical warm-core high pressure where the air from the upper troposphere usually descends, warming and drying the lower troposphere and preventing cloud formation.

The permanent absence of clouds allows unhindered light and thermal radiation. The stability of the atmosphere above the desert prevents any convective overturning, thus making rainfall virtually non-existent. As a consequence, the weather tends to be sunny, dry and stable with a minimal chance of rainfall. Subsiding, diverging, dry air masses associated with subtropical high-pressure systems are extremely unfavorable for the development of convectional showers. The subtropical ridge is the predominant factor that explains the hot desert climate (Köppen climate classification ''BWh'') of this vast region. The descending airflow is the strongest and the most effective over the eastern part of the Great Desert, in the Libyan Desert: this is the sunniest, driest and the most nearly "rainless" place on the planet, rivaling the Atacama Desert, lying in Chile and Peru.

The rainfall inhibition and the dissipation of cloud cover are most accentuated over the eastern section of the Sahara rather than the western. The prevailing air mass lying above the Sahara is the continental tropical (cT) air mass, which is hot and dry. Hot, dry air masses primarily form over the North-African desert from the heating of the vast continental land area, and it affects the whole desert during most of the year. Because of this extreme heating process, a thermal low is usually noticed near the surface, and is the strongest and the most developed during the summertime. The Sahara High represents the eastern continental extension of the Azores High,{{citation needed|date=August 2016}} centered over the North Atlantic Ocean. The subsidence of the Sahara High nearly reaches the ground during the coolest part of the year, while it is confined to the upper troposphere during the hottest periods.

The effects of local surface low pressure are extremely limited because upper-level subsidence still continues to block any form of air ascent. Also, to be protected against rain-bearing weather systems by the atmospheric circulation itself, the desert is made even drier by its geographical configuration and location. Indeed, the extreme aridity of the Sahara is not only explained by the subtropical high pressure: the Atlas Mountains of Algeria, Morocco and Tunisia also help to enhance the aridity of the northern part of the desert. These major mountain ranges act as a barrier, causing a strong rain shadow effect on the leeward side by dropping much of the humidity brought by atmospheric disturbances along the polar front which affects the surrounding Mediterranean climates.

The primary source of rain in the Sahara is the Intertropical Convergence Zone, a continuous belt of low-pressure systems near the equator which bring the brief, short and irregular rainy season to the Sahel and southern Sahara. Rainfall in this giant desert has to overcome the physical and atmospheric barriers that normally prevent the production of precipitation. The harsh climate of the Sahara is characterized by: extremely low, unreliable, highly erratic rainfall; extremely high sunshine duration values; high temperatures year-round; negligible rates of relative humidity; a significant diurnal temperature variation; and extremely high levels of potential evaporation which are the highest recorded worldwide.<ref>{{cite book |last=Griffiths |first=Ieuan L.I. |title=The Atlas of African Affairs |url=https://books.google.com/books?id=8C40QP8vyU0C&q=Sahara+Desert+a+wide+area+experiences+in+excess+of&pg=PA15 |publisher=Routledge |date=17 June 2013 |isbn=978-1-135-85552-9 |access-date=20 November 2020 |archive-date=30 July 2023 |archive-url=https://web.archive.org/web/20230730165156/https://books.google.com/books?id=8C40QP8vyU0C&q=Sahara+Desert+a+wide+area+experiences+in+excess+of&pg=PA15 |url-status=live }}</ref>

===Temperature=== The sky is usually clear above the desert, and the sunshine duration is extremely high everywhere in the Sahara. Most of the desert has more than 3,600 hours of bright sunshine per year (over 82% of daylight hours), and a wide area in the eastern part has over 4,000 hours of bright sunshine per year (over 91% of daylight hours). The highest values are very close to the theoretical maximum: a value of 4,300 hours, representing 98% of the total number of daylight hours per year, has been recorded both in Upper Egypt (Aswan, Luxor) and in the Nubian Desert (Wadi Halfa).<ref name="books.google.fr">{{cite book |last=Oliver |first=John E. |title=Encyclopedia of World Climatology |url=https://books.google.com/books?id=-mwbAsxpRr0C&q=4,300+hours+of+sunshine+Wadi+Halfa&pg=PA13 |publisher=Springer Science & Business Media |date=23 April 2008 |isbn=978-1-4020-3264-6 |access-date=20 November 2020 |archive-date=30 July 2023 |archive-url=https://web.archive.org/web/20230730165157/https://books.google.com/books?id=-mwbAsxpRr0C&q=4,300+hours+of+sunshine+Wadi+Halfa&pg=PA13 |url-status=live }}</ref> The annual average direct solar irradiation is around 2,800 kWh/(m2 year) in the Great Desert. The Sahara has a huge potential for solar energy production.[[File:Algeria Sahara Desert Photo From Drone 5.jpg|thumb|Sand dunes in the Algerian Sahara]]

The high position of the Sun, the extremely low relative humidity, and the lack of vegetation and rainfall make the Great Desert the hottest large region in the world, and the hottest place on Earth during summer in some spots. The average high temperature exceeds {{convert|38|to|40|C|F|1}} during the hottest month nearly everywhere in the desert except at very high altitudes. The world's highest mean monthly maximum temperature was {{convert|47|C|F|1}} in a remote desert town in the Algerian Desert called Bou Bernous, at an elevation of {{convert|378|m|ft}} above sea level;<ref name="books.google.fr"/> it is rivaled only by Death Valley, California.<ref>{{cite book|last1=Griffiths|first1=John F.|last2=Driscoll|first2=Dennis M.|title=Survey of Climatology|publisher=C.E. Merrill Publishing Company|isbn=978-0-675-09994-3|url=https://books.google.com/books?id=8yxRAAAAMAAJ&q=bou+bernous+average|year=1982|access-date=25 August 2020|archive-date=30 July 2023|archive-url=https://web.archive.org/web/20230730165157/https://books.google.com/books?id=8yxRAAAAMAAJ&q=bou+bernous+average|url-status=live}}</ref>

Other hot spots in Algeria such as Adrar, Timimoun, In Salah, Ouallene, Aoulef, Reggane with an elevation between {{convert|200|and|400|m|ft}} above sea level get slightly lower summer average highs, around {{convert|46|C|F|1}} during the hottest months of the year. Salah, well known in Algeria for its extreme heat, has average high temperatures of {{convert|43.8|C|F|1}}, {{convert|46.4|C|F|1}}, {{convert|45.5|C|F|1}} and {{convert|41.9|C|F|1}} in June, July, August and September respectively. There are even hotter spots in the Sahara, but they are located in extremely remote areas, especially in the Azalai, lying in northern Mali. The major part of the desert experiences around three to five months when the average high exceeds {{convert|40|C|F}}; while in the southern central part of the desert, there are up to six or seven months when the average high temperature exceeds {{convert|40|C|F}}. Some examples of this are Bilma, Niger and Faya-Largeau, Chad. The annual average daily temperature exceeds {{convert|20|C|F}} everywhere and can approach {{convert|30|C|F}} in the hottest regions year-round. However, most of the desert has a value in excess of {{convert|25|C|F}}.

[[File:Sunset in Sahara.jpg|thumb|Camel train at sunset in the Sahara]]

Sand and ground temperatures are even more extreme. During daytime, the sand temperature is extremely high: it can easily reach {{convert|80|C|F}} or more.<ref name="ReferenceB">{{cite book|last=Nicholson|first=Sharon E.|title=Dryland Climatology|publisher=Cambridge University Press|isbn=978-1-139-50024-1|url=https://books.google.com/books?id=fqussIGJ0NcC&q=Port-Sudan+84+%C2%B0C&pg=PA158|date=27 October 2011|access-date=20 November 2020|archive-date=30 July 2023|archive-url=https://web.archive.org/web/20230730165231/https://books.google.com/books?id=fqussIGJ0NcC&q=Port-Sudan+84+%C2%B0C&pg=PA158|url-status=live}}</ref> A sand temperature of {{convert|83.5|C|F}} has been recorded in Port Sudan.<ref name="ReferenceB"/> Ground temperatures of {{convert|72|C|F|1}} have been recorded in the Adrar of Mauritania and a value of {{convert|75|C|F}} has been measured in Borkou, northern Chad.<ref name="ReferenceB"/>

Due to lack of cloud cover and very low humidity, the desert usually has high diurnal temperature variations between days and nights. However, it is a myth that the nights are especially cold after extremely hot days in the Sahara.{{citation needed|date=February 2020}} On average, nighttime temperatures tend to be {{convert|13–20|C-change}} cooler than in the daytime. The smallest variations are found along the coastal regions due to high humidity and are often even lower than a {{convert|10|C-change|F-change}} difference, while the largest variations are found in inland desert areas where the humidity is the lowest, mainly in the southern Sahara. Still, it is true that winter nights can be cold, as it can drop to the freezing point and even below, especially in high-elevation areas. The frequency of subfreezing winter nights in the Sahara is strongly influenced by the North Atlantic Oscillation (NAO), with warmer winter temperatures during negative NAO events and cooler winters with more frosts when the NAO is positive.<ref>{{cite journal |last1=Visbeck |first1=Martin H. |last2=Hurrell |first2=James W. |last3=Polvani |first3=Lorenzo |last4=Cullen |first4=Heidi M. |title=The North Atlantic Oscillation: Past, present, and future |journal=Proceedings of the National Academy of Sciences |date=6 November 2001 |volume=98 |issue=23 |pages=12876–12877 |doi=10.1073/pnas.231391598 |pmid=11687629 |pmc=60791 |bibcode=2001PNAS...9812876V |doi-access=free }}</ref> This is because the weaker clockwise flow around the eastern side of the subtropical anticyclone during negative NAO winters, although too dry to produce more than negligible precipitation, does reduce the flow of dry, cold air from higher latitudes of Eurasia into the Sahara significantly.<ref>{{cite book |last1=Hurrell |first1=James W. |last2=Kushnir |first2=Yochanan |last3=Ottersen |first3=Geir |last4=Visbeck |first4=Martin |title=The North Atlantic Oscillation: Climatic Significance and Environmental Impact |chapter=An overview of the North Atlantic Oscillation |series=Geophysical Monograph Series |date=2003 |volume=134 |pages=1–35 |doi=10.1029/134GM01 |isbn=0-87590-994-9 }}</ref>

===Precipitation=== The average annual rainfall ranges from very low in the northern and southern fringes of the desert to nearly non-existent over the central and the eastern part. The thin northern fringe of the desert receives more winter cloudiness and rainfall due to the arrival of low pressure systems over the Mediterranean Sea along the polar front, although very attenuated by the rain shadow effects of the mountains and the annual average rainfall ranges from {{convert|100|mm|in|0}} to {{convert|250|mm|in|0}}. For example, Biskra, Algeria, and Ouarzazate, Morocco, are found in this zone. The southern fringe of the desert along the border with the Sahel receives summer cloudiness and rainfall due to the arrival of the Intertropical Convergence Zone from the south and the annual average rainfall ranges from {{convert|100|mm|in|0}} to {{convert|250|mm|in|0}}. For example, Timbuktu, Mali and Agadez, Niger are found in this zone.

The vast central hyper-arid core of the desert is virtually never affected by northerly or southerly atmospheric disturbances and permanently remains under the influence of the strongest anticyclonic weather regime, and the annual average rainfall can drop to less than {{convert|1|mm|in|2}}. In fact, most of the Sahara receives less than {{convert|20|mm|in|1}}. Of the {{convert|9000000|km2|sqmi}} of desert land in the Sahara, an area of about {{convert|2800000|km2|sqmi}} (about 31% of the total area) receives an annual average rainfall amount of {{convert|10|mm|in|1}} or less, while some {{convert|1500000|km2|sqmi}} (about 17% of the total area) receives an average of {{convert|5|mm|in|sigfig=1}} or less.<ref name="ReferenceA">{{cite book|last1=Houérou|first1=Henry N.|title=Bioclimatology and Biogeography of Africa|publisher=Springer Science & Business Media|isbn=978-3-540-85192-9|url=https://books.google.com/books?id=_Rvs7NkfeLEC&q=Sahara+rainfall+virtually+zero&pg=PA16|date=10 December 2008|access-date=20 November 2020|archive-date=30 July 2023|archive-url=https://web.archive.org/web/20230730160547/https://books.google.com/books?id=_Rvs7NkfeLEC&q=Sahara+rainfall+virtually+zero&pg=PA16|url-status=live}}</ref>

The annual average rainfall is virtually zero over a wide area of some {{convert|1000000|km2|sqmi}} in the eastern Sahara comprising deserts of: Libya, Egypt and Sudan (Tazirbu, Kufra, Dakhla, Kharga, Farafra, Siwa, Asyut, Sohag, Luxor, Aswan, Abu Simbel, Wadi Halfa) where the long-term mean approximates {{convert|0.5|mm|in|sigfig=1}} per year.<ref name="ReferenceA"/> Rainfall is very unreliable and erratic in the Sahara as it may vary considerably year by year. In full contrast to the negligible annual rainfall amounts, the annual rates of potential evaporation are extraordinarily high, roughly ranging from {{convert|2500|mm|in|-1}} per year to more than {{convert|6000|mm|in}} per year in the whole desert.<ref>{{cite book|last1=Brown|first1=G.W.|title=Desert Biology: Special Topics on the Physical and Biological Aspects of Arid Regions|publisher=Elsevier|isbn=978-1-4832-1663-8|url=https://books.google.com/books?id=EiTLBAAAQBAJ&q=Sahara+Desert+nebulosity&pg=PA122|date=17 September 2013|access-date=20 November 2020|archive-date=30 July 2023|archive-url=https://web.archive.org/web/20230730165232/https://books.google.com/books?id=EiTLBAAAQBAJ&q=Sahara+Desert+nebulosity&pg=PA122|url-status=live}}</ref> Nowhere else on Earth has air been found as dry and evaporative as in the Sahara region. However, at least two instances of snowfall have been recorded in Sahara, in February 1979 and December 2016, both in the town of Ain Sefra.<ref>{{cite web| url =https://edition.cnn.com/travel/article/sahara-snow/index.html| title =Snow falls in Sahara for first time in 37 years| publisher =CNN| date =21 December 2016| access-date =22 December 2016| archive-date =23 December 2016| archive-url =https://web.archive.org/web/20161223063303/http://edition.cnn.com/2016/12/21/travel/sahara-snow/| url-status =live}}</ref>

===Desertification and prehistoric climate=== {{main|Sahara pump theory|African humid period|Prehistoric North Africa|North African climate cycles}} [[File:Journal.pone.0076514.g004.png|thumb|Vegetation and water bodies in early Holocene (top), between about 12,000 and 7,000 years ago, and Eemian (bottom)]] One theory for the formation of the Sahara is that the monsoon in Northern Africa was weakened because of glaciation during the Quaternary period, starting two or three million years ago. Another theory is that the monsoon was weakened when the ancient Tethys Sea dried up during the Tortonian period around 7 million years ago.<ref>{{cite journal |last1=Zhang |first1=Zhongshi |last2=Ramstein |first2=Gilles |last3=Schuster |first3=Mathieu |last4=Li |first4=Camille |last5=Contoux |first5=Camille |last6=Yan |first6=Qing |title=Aridification of the Sahara desert caused by Tethys Sea shrinkage during the Late Miocene |journal=Nature |date=2014 |volume=513 |issue=7518 |pages=401–404 |doi=10.1038/nature13705 |pmid=25230661 |bibcode=2014Natur.513..401Z }}</ref>

The climate of the Sahara has undergone enormous variations between wet and dry over the last few hundred thousand years,<ref name="Lakes">{{cite journal |last1=White |first1=Kevin |last2=Mattingly |first2=David J. |title=Ancient Lakes of the Sahara |journal=American Scientist |volume=94 |year=2006 |pages=58–65 |issue=1|doi=10.1511/2006.57.983 }}</ref> believed to be caused by long-term changes in the North African climate cycle that alters the path of the North African Monsoon – usually southward. The cycle is caused by a 41,000-year cycle in which the tilt of the earth changes between 22° and 24.5°.<ref name="ReferenceA"/> At present, it is in a dry period, but it is expected that the Sahara will become green again in 15,000 years. When the North African monsoon is at its strongest, annual precipitation and subsequent vegetation in the Sahara region increase, resulting in conditions commonly referred to as the "green Sahara". For a relatively weak North African monsoon, the opposite is true, with decreased annual precipitation and less vegetation resulting in a phase of the Sahara climate cycle known as the "desert Sahara".<ref name="Foley1">{{cite journal |last1=Foley |first1=Jonathan A. |last2=Coe |first2=Michael T. |last3=Scheffer |first3=Marten |last4=Wang |first4=Guiling |title=Regime Shifts in the Sahara and Sahel: Interactions between Ecological and Climatic Systems in Northern Africa |journal=Ecosystems |date=1 October 2003 |volume=6 |issue=6 |pages=524–539 |doi=10.1007/s10021-002-0227-0 |bibcode=2003Ecosy...6..524F }}</ref>

The idea that changes in insolation (solar heating) caused by long-term changes in Earth's orbit are a controlling factor for the long-term variations in the strength of monsoon patterns across the globe was first suggested by Rudolf Spitaler in the late nineteenth century,<ref name="Ruddiman3">{{cite book |last1=Ruddiman |first1=William F. |title=Earth's Climate: Past and Future |publisher=W.H. Freeman and Company |location=New York |date=2001 |isbn=978-0-7167-3741-4}}</ref> The hypothesis was later formally proposed and tested by the meteorologist John Kutzbach in 1981.<ref name="Kutzbach4">{{cite journal |last1=Kutzbach |first1=J.E. |title=Monsoon Climate of the Early Holocene: Climate Experiment with the Earth's Orbital Parameters for 9000 Years Ago |journal=Science |date=2 October 1981 |volume=214 |issue=4516 |pages=59–61 |doi=10.1126/science.214.4516.59 |pmid=17802573 |bibcode=1981Sci...214...59K }}</ref> Kutzbach's ideas about the impacts of insolation on global monsoonal patterns have become widely accepted today as the underlying driver of long-term monsoonal cycles. Kutzbach never formally named his hypothesis and as such it is referred to here as the "Orbital Monsoon Hypothesis" as suggested by Ruddiman in 2001.<ref name="Ruddiman3" /> [[File:Village Telly in Mali.jpg|thumb|Sahel region of Mali]]

During the last glacial period, the Sahara was much larger than it is today, extending south beyond its current boundaries.<ref>Ehret, Christopher, ''The Civilizations of Africa'', University Press of Virginia, 2002.</ref> The end of the glacial period brought more rain to the Sahara, from about 8000 BCE to 6000 BCE, perhaps because of low pressure areas over the collapsing ice sheets to the north.<ref>{{cite web |title=Fezzan Project - Palaeoclimate and environment |url=http://www.cru.uea.ac.uk/~e118/Fezzan/fezzan_palaeoclim.html |archive-url=https://web.archive.org/web/20090607025201/http://www.cru.uea.ac.uk/~e118/Fezzan/fezzan_palaeoclim.html |archive-date=7 June 2009 }}{{self-published inline|date=May 2026}}</ref> Once the ice sheets were gone, the northern Sahara dried out. In the southern Sahara, the drying trend was initially counteracted by the monsoon, which brought rain further north than it does today. By around 4200 BCE, however, the monsoon retreated south to approximately where it is today,<ref name="Science Daily">{{cite press release |title=Sahara's Abrupt Desertification Started By Changes In Earth's Orbit, Accelerated By Atmospheric And Vegetation Feedbacks |url=https://www.sciencedaily.com/releases/1999/07/990712080500.htm |work=ScienceDaily |publisher=American Geophysical Union |date=12 July 1999 }}</ref> leading to the gradual desertification of the Sahara.<ref>{{cite journal |last1=Kröpelin |first1=S. |last2=Verschuren |first2=D. |last3=Lézine |first3=A.-M. |last4=Eggermont |first4=H. |last5=Cocquyt |first5=C. |last6=Francus |first6=P. |last7=Cazet |first7=J.-P. |last8=Fagot |first8=M. |last9=Rumes |first9=B. |last10=Russell |first10=J. M. |last11=Darius |first11=F. |last12=Conley |first12=D. J. |last13=Schuster |first13=M. |last14=von Suchodoletz |first14=H. |last15=Engstrom |first15=D. R. |title=Climate-Driven Ecosystem Succession in the Sahara: The Past 6000 Years |journal=Science |date=2008 |volume=320 |issue=5877 |pages=765–768 |doi=10.1126/science.1154913 |pmid=18467583 |bibcode=2008Sci...320..765K }}</ref> The Sahara is now as dry as it was about 13,000 years ago.<ref name=Lakes/>

Lake Chad is the remnant of a former inland sea, paleolake Mega-Chad, which existed during the African humid period. At its largest extent, sometime before 5000 BCE, Lake Mega-Chad was the largest of four Saharan paleolakes, and is estimated to have covered an area of 350,000 km2.<ref>{{cite journal |last1=Quade |first1=J. |last2=Dente |first2=E. |last3=Armon |first3=M. |last4=Ben Dor |first4=Y. |last5=Morin |first5=E. |last6=Adam |first6=O. |last7=Enzel |first7=Y. |title=Megalakes in the Sahara? A Review |journal=Quaternary Research |date=2018 |volume=90 |issue=2 |pages=253–275 |doi=10.1017/qua.2018.46 |bibcode=2018QuRes..90..253Q }}</ref>

The Sahara pump theory describes this cycle. During periods of a wet or "Green Sahara", the Sahara becomes a savanna grassland and various flora and fauna become more common. Following inter-pluvial arid periods, the Sahara area then reverts to desert conditions and the flora and fauna are forced to retreat northwards to the Atlas Mountains, southwards into West Africa, or eastwards into the Nile Valley. This separates populations of some of the species in areas with different climates, forcing them to adapt, possibly giving rise to allopatric speciation. [[File:Great green wall map.svg|thumb|The Great Green Wall, participating countries and Sahel. In August 2023, it was reported that the GGW had only covered 18% of the planned area.<ref>{{cite news|author=Spoorthy Raman|title=Progress is slow on Africa's Great Green Wall, but some bright spots bloom|url=https://news.mongabay.com/2023/08/progress-is-slow-on-africas-great-green-wall-but-some-bright-spots-bloom/|newspaper=Mongabay|date=3 August 2023|via=news.mongabay.com|access-date=4 April 2024|archive-date=4 April 2024|archive-url=https://web.archive.org/web/20240404202948/https://news.mongabay.com/2023/08/progress-is-slow-on-africas-great-green-wall-but-some-bright-spots-bloom|url-status=live}}</ref>]]

It is also proposed that humans accelerated the drying-out period from 6000 to 2500 BCE by pastoralists overgrazing available grassland.<ref>{{cite news|url=http://www.smithsonianmag.com/science-nature/what-really-turned-sahara-desert-green-oasis-wasteland-180962668/|title=What Really Turned the Sahara Desert From a Green Oasis into a Wasteland?|last=Boissoneault|first=Lorraine|date=24 March 2017|work=Smithsonian|access-date=15 August 2017|archive-date=28 December 2021|archive-url=https://web.archive.org/web/20211228124940/https://www.smithsonianmag.com/science-nature/what-really-turned-sahara-desert-green-oasis-wasteland-180962668/|url-status=live}}</ref>

==== Evidence for cycles ==== The growth of speleothems (which requires rainwater) was detected in Hol-Zakh, Ashalim, Even-Sid, Ma'ale-ha-Meyshar, Ktora Cracks, Nagev Tzavoa Cave, and elsewhere, and has allowed tracking of prehistoric rainfall. The Red Sea coastal route was extremely arid before 140 and after 115 kya (thousands of years ago). Slightly wetter conditions appear at 90–87 kya, but it still was just one tenth the rainfall around 125 kya. In the southern Negev Desert speleothems did not grow between 185 and 140 kya (MIS 6), 110–90 (MIS 5.4–5.2), nor after 85 kya nor during most of the interglacial period (MIS 5.1), the glacial period and Holocene. This suggests that the southern Negev was arid-to-hyper-arid in these periods.<ref name=Vaks2007>{{cite journal |last1=Vaks |first1=Anton |last2=Bar-Matthews |first2=Miryam |last3=Ayalon |first3=Avner |last4=Matthews |first4=Alan |last5=Halicz |first5=Ludwik |last6=Frumkin |first6=Amos |title=Desert speleothems reveal climatic window for African exodus of early modern humans |url=http://earth.huji.ac.il/data/pics/Vax%20et%20al%202007.pdf |journal=Geology |volume=35 |issue=9 |page=831 |year=2007 |archive-url=https://web.archive.org/web/20110721133642/http://earth.huji.ac.il/data/pics/Vax%20et%20al%202007.pdf |archive-date=21 July 2011 |bibcode=2007Geo....35..831V |doi=10.1130/G23794A.1}}</ref>

During the Last Glacial Maximum (LGM) the Sahara was more extensive than it is now with the extent of the tropical forests being greatly reduced,<ref>{{cite web |last=Adams |first=Jonathan |title=Africa during the last 150,000 years |url=http://www.esd.ornl.gov/projects/qen/nercAFRICA.html |publisher=Environmental Sciences Division, ORNL Oak Ridge National Laboratory |archive-url=https://web.archive.org/web/20060501225402/http://www.esd.ornl.gov/projects/qen/nercAFRICA.html |archive-date=1 May 2006}}</ref> and the lower temperatures reduced the strength of the Hadley Cell. This is a climate cell which causes rising tropical air of the Inter-Tropical Convergence Zone (ITCZ) to bring rain to the tropics, while dry descending air, at about 20 degrees north, flows back to the equator and brings desert conditions to this region. It is associated with high rates of wind-blown mineral dust, and these dust levels are found as expected in marine cores from the north tropical Atlantic. But around 12,500 BCE the amount of dust in the cores in the Bølling/Allerød phase suddenly plummets and shows a period of much wetter conditions in the Sahara, indicating a Dansgaard-Oeschger (DO) event (a sudden warming followed by a slower cooling of the climate). The moister Saharan conditions had begun about 12,500 BCE, with the extension of the ITCZ northward in the northern hemisphere summer, bringing moist wet conditions and a savanna climate to the Sahara, which (apart from a short dry spell associated with the Younger Dryas) peaked during the Holocene thermal maximum climatic phase at 4000 BCE when mid-latitude temperatures seem to have been between 2 and 3 degrees warmer than in the recent past. Analysis of Nile River deposited sediments in the delta also shows this period had a higher proportion of sediments coming from the Blue Nile, suggesting higher rainfall also in the Ethiopian Highlands. This was caused principally by a stronger monsoonal circulation throughout the sub-tropical regions, affecting India, Arabia and the Sahara.{{Citation needed|date=August 2009}} Lake Victoria only recently became the source of the White Nile and dried out almost completely around 15 kya.<ref>{{Cite journal | doi = 10.1007/s10750-007-9158-2 | title = The late Pleistocene desiccation of Lake Victoria and the origin of its endemic biota | year = 2008 | author = Stager, J.C. | journal = Hydrobiologia | volume = 596 | pages = 5–16 | last2 = Johnson | first2 = T.C. | issue = 1 | bibcode = 2008HyBio.596....5S }}</ref>

The sudden subsequent movement of the ITCZ southwards with a Heinrich event (a sudden cooling followed by a slower warming), linked to changes with the El Niño-Southern Oscillation cycle, led to a rapid drying out of the Saharan and Arabian regions, which quickly became desert. This is linked to a marked decline in the scale of the Nile floods between 2700 and 2100 BCE.<ref>Burroughs, William J. (2007) "Climate Change in Prehistory: the end of the reign of chaos" (Cambridge University Press)</ref>

==Ecoregions== thumb|upright=1.75|The major topographic features of the Saharan region

The Sahara comprises several distinct ecoregions. With their variations in temperature, rainfall, elevation, and soil, these regions harbor distinct communities of plants and animals.

* The Atlantic coastal desert is a narrow strip along the Atlantic coast where fog generated offshore by the cool Canary Current provides sufficient moisture to sustain a variety of lichens, succulents, and shrubs. It covers an area of {{convert|39900|km2|sqmi|sp=us}} in the south of Morocco and Mauritania.<ref>{{WWF ecoregion|id=pa1304|name=Atlantic coastal desert|access-date=29 December 2007}}</ref> * The North Saharan steppe and woodlands is along the northern desert, next to the Mediterranean forests, woodlands, and scrub ecoregions of the northern Maghreb and Cyrenaica. Winter rains sustain shrublands and dry woodlands that form a transition between the Mediterranean climate regions to the north and the hyper-arid Sahara proper to the south. It covers {{convert|1675300|km2|sqmi|sp=us|sigfig=5}} in Algeria, Egypt, Libya, Mauritania, Morocco, and Tunisia.<ref>{{WWF ecoregion|id=pa1321|name=North Saharan steppe and woodlands|access-date=29 December 2007}}</ref> * The Sahara desert ecoregion covers the hyper-arid central portion of the Sahara where rainfall is minimal and sporadic. Vegetation is rare, and this ecoregion consists mostly of sand dunes (''erg, chech, raoui''), stone plateaus (''hamadas''), gravel plains (''reg''), dry valleys (''wadis''), and salt flats. It covers {{convert|4639900|km2|sqmi}} of: Algeria, Chad, Egypt, Libya, Mali, Mauritania, Niger, and Sudan.<ref name="PA1327" /> * The South Saharan steppe and woodlands ecoregion is a narrow band running east and west between the hyper-arid Sahara and the Sahel savannas to the south. Movements of the equatorial Intertropical Convergence Zone (ITCZ) bring summer rains during July and August which average {{convert|100|to|200|mm|abbr=on|sigfig=1|in}} but vary greatly from year to year. These rains sustain summer pastures of grasses and herbs, with dry woodlands and shrublands along seasonal watercourses. This ecoregion covers {{convert|1101700|km2|sqmi}} in Algeria, Chad, Mali, Mauritania, and Sudan.<ref>{{WWF ecoregion|id=pa1329|name=South Saharan steppe and woodlands|access-date=29 December 2007}}</ref> * In the West Saharan montane xeric woodlands, several volcanic highlands provide a cooler, moister environment that supports Saharo-Mediterranean woodlands and shrublands. The ecoregion covers {{convert|258100|km2|sqmi|sigfig=4}}, mostly in the Tassili n'Ajjer of Algeria, with smaller enclaves in the Aïr of Niger, the Adrar Plateau of Mauritania, and the Adrar des Iforas of Mali and Algeria.<ref>{{WWF ecoregion|id=pa1332|name=West Saharan montane xeric woodlands|access-date=29 December 2007}}</ref> * The Tibesti-Jebel Uweinat montane xeric woodlands ecoregion consists of the Tibesti and Jebel Uweinat highlands. Higher and more regular rainfall and cooler temperatures support woodlands and shrublands of date palm, acacias, myrtle, oleander, tamarix, and several rare and endemic plants. The ecoregion covers {{convert|82200|km2|sqmi}} in the Tibesti of Chad and Libya, and Jebel Uweinat on the border of Egypt, Libya, and Sudan.<ref>{{WWF ecoregion|id=pa1331|name=Tibesti-Jebel Uweinat montane xeric woodlands|access-date=29 December 2007}}</ref> * The Saharan halophytics is an area of seasonally flooded saline depressions which is home to halophytic (salt-adapted) plant communities. The Saharan halophytics cover {{convert|54000|km2|sqmi}} including: the Qattara and Siwa depressions in northern Egypt, the Tunisian salt lakes of central Tunisia, Chott Melghir in Algeria, and smaller areas of Algeria, Mauritania, and the southern part of Morocco.<ref>{{WWF ecoregion|id=pa0905|name=Saharan halophytics|access-date=29 December 2007}}</ref> * The Tanezrouft is one of the Sahara's most arid regions, with no vegetation and very little life. A barren, flat gravel plain, it extends south of Reggane in Algeria towards the Adrar des Ifoghas highlands in northern Mali.

==Flora and fauna== The flora of the Sahara is highly diversified based on the bio-geographical characteristics of this vast desert. Floristically, the Sahara has three zones based on the amount of rainfall received – the Northern (Mediterranean), Central and Southern Zones. There are two transitional zones – the Mediterranean-Sahara transition and the Sahel transition zone.<ref name="Mares1999">{{cite book|editor=Mares, Michael A.|title=Encyclopedia of Deserts|url=https://books.google.com/books?id=g3CbqZtaF4oC&pg=PA490|year=1999|publisher=University of Oklahoma Press|isbn=978-0-8061-3146-7|page=490|access-date=15 November 2015|archive-date=30 July 2023|archive-url=https://web.archive.org/web/20230730165156/https://books.google.com/books?id=g3CbqZtaF4oC&pg=PA490|url-status=live}}</ref>

The Saharan flora comprises around 2800 species of vascular plants. Approximately a quarter of these are endemic. About half of these species are common to the flora of the Arabian deserts.<ref name="Houérou2008">{{cite book|last=Houérou|first=Henry N.|title=Bioclimatology and Biogeography of Africa|url=https://books.google.com/books?id=_Rvs7NkfeLEC&pg=PA82|year=2008|publisher=Springer|isbn=978-3-540-85192-9|page=82|access-date=15 November 2015|archive-date=30 July 2023|archive-url=https://web.archive.org/web/20230730165657/https://books.google.com/books?id=_Rvs7NkfeLEC&pg=PA82|url-status=live}}</ref>

[[File:GueltaCamels.jpg|thumb|Camels in the Guelta d'Archei, in north-eastern Chad]] The central Sahara is estimated to include five hundred species of plants, which is extremely low considering the huge extent of the area. Plants such as acacia trees, palms, succulents, spiny shrubs, and grasses have adapted to the arid conditions, by growing lower to avoid water loss by strong winds, by storing water in their thick stems to use it in dry periods, by having long roots that travel horizontally to reach the maximum area of water and to find any surface moisture, and by having small thick leaves or needles to prevent water loss by evapotranspiration. Plant leaves may dry out totally and then recover.

{{Anchor|Fauna}}Several species of fox live in the Sahara including: the fennec fox, pale fox and Rüppell's fox. The addax, a large white antelope, can go nearly a year in the desert without drinking. The dorcas gazelle is a north African gazelle that can also go for a long time without water. Other notable gazelles include the rhim gazelle and dama gazelle.

The Saharan cheetah (northwest African cheetah) lives in Algeria, Togo, Niger, Mali, Benin, and Burkina Faso. There remain fewer than 250 mature cheetahs, which are very cautious, fleeing any human presence. The cheetah avoids the sun from April to October, seeking the shelter of shrubs such as balanites and acacias. They are unusually pale.<ref>{{cite news |url=http://news.bbc.co.uk/2/hi/science/nature/7905986.stm |title=Rare cheetah captured on camera |work=BBC News |date=24 February 2009 |access-date=12 June 2010 |archive-date=1 August 2010 |archive-url=https://web.archive.org/web/20100801021134/http://news.bbc.co.uk/2/hi/science/nature/7905986.stm |url-status=live }}</ref><ref>{{cite iucn |author=Belbachir, F. |date=2008 |title=''Acinonyx jubatus'' ssp. ''hecki'' |volume=2008 |article-number=e.T221A13035738 |doi=10.2305/IUCN.UK.2008.RLTS.T221A13035738.en |access-date=13 November 2021}}</ref> The other cheetah subspecies (northeast African cheetah) lives in Chad, Sudan and the eastern region of Niger. However, it is currently extinct in the wild in Egypt and Libya. There are approximately 2000 mature individuals left in the wild.

[[File:Libya 5391 Ubari Lakes Luca Galuzzi 2007.jpg|thumb|left|An Idehan Ubari oasis lake, with native grasses and date palms]] Other animals include the monitor lizards, hyrax, sand vipers, and small populations of African wild dog,<ref name=iucn>{{cite iucn |author=Woodroffe, R. |author2=Sillero-Zubiri, C. |date=2020 |title=''Lycaon pictus'' |volume=2020 |article-number=e.T12436A166502262 |doi=10.2305/IUCN.UK.2020-1.RLTS.T12436A166502262.en |access-date=13 November 2021}}</ref> in perhaps only 14 countries<ref name=Borrell>{{cite magazine|url=http://www.slate.com/id/2225607/entry/2225663/ |title=Endangered in South Africa: Those Doggone Conservationists |first=Brendan |last=Borrell |magazine=Slate |date=19 August 2009 |archive-url=https://web.archive.org/web/20110430173131/http://www.slate.com/id/2225607/entry/2225663/ |archive-date=30 April 2011 }}</ref> and red-necked ostrich. Other animals exist in the Sahara (birds in particular) such as African silverbill and black-faced firefinch, among others. There are also small desert crocodiles in Mauritania and the Ennedi Plateau of Chad.<ref>"[http://news.nationalgeographic.com/news/2002/06/0617_020618_croc.html Desert-Adapted Crocs Found in Africa] {{Webarchive|url=https://web.archive.org/web/20180722011655/http://news.nationalgeographic.com/news/2002/06/0617_020618_croc.html |date=22 July 2018 }}", National Geographic News, 18 June 2002</ref>

The deathstalker scorpion can be {{convert|10|cm|in|abbr=on}} long. Its venom contains large amounts of agitoxin and scyllatoxin, though its sting rarely kills a healthy adult. The Saharan silver ant is unique in that due to the extreme high temperatures of their habitat, and the threat of predators, the ants are active outside their nest for only about ten minutes per day.<ref name="WehnerEtAl1992">{{cite journal |last1=Wehner |first1=R. |last2=Marsh |first2=A.C. |last3=Wehner |first3=S. |year=1992 |title=Desert ants on a thermal tightrope |journal=Nature |volume=357 |issue=6379 |pages=586–87 |doi=10.1038/357586a0 |bibcode=1992Natur.357..586W }}</ref>

Dromedary camels and goats are the domesticated animals most commonly found in the Sahara. Because of its qualities of endurance and speed, the dromedary is the favourite animal used by nomads.

Human activities are more likely to affect the habitat in areas of permanent water (oases) or where water comes close to the surface. Here, the local pressure on natural resources can be intense. The remaining populations of large mammals have been greatly reduced by hunting for food and recreation. In recent years development projects have started in the deserts of Algeria and Tunisia using irrigated water pumped from underground aquifers. These schemes often lead to soil degradation and salinization.

Researchers from Hacettepe University have reported that Saharan soil may have bio-available iron and also some essential macro and micro nutrient elements suitable for use as fertilizer for growing wheat.<ref name="YTSB2011">{{Cite journal |last1=Yücekutlu |first1=Nihal |last2=Terzioğlu |first2=Serpil |last3=Saydam |first3=Cemal |last4=Bildacı |first4=Işık |date=January 1, 2011 |title=Organic Farming By Using Saharan Soil: Could It Be An Alternative To Fertilizers? |url=https://dergipark.org.tr/en/pub/hjbc/article/925990 |journal=Hacettepe Journal of Biology and Chemistry |volume=39 |issue=1 |pages=29–37 }}</ref>

== History == [[File:Mathendous giraffes.jpg|thumb|Saharan rock art in the Fezzan]]

Scientists have identified more than 230 humid periods in North Africa, occurring every 21,000 years for the past eight million years.<ref>{{cite news |title=North African humid periods over the past 800,000 years |url=https://www.nature.com/articles/s41467-023-41219-4 |work=Nature |date=8 September 2023}}</ref><ref>{{cite news |title=The Sahara Desert used to be a green savannah: Research explains why |url=https://phys.org/news/2023-12-sahara-green-savannah.html |work=Phys.org |date=16 December 2023}}</ref><ref>{{cite news |title=How a wobbly earth and green Sahara led to the spread of humans |url=https://africageographic.com/stories/how-a-wobbly-earth-and-green-sahara-led-to-the-spread-of-humans/ |work=Africa Geographic |date=28 March 2024}}</ref>

A modern laboratory examination of the Uan Muhuggiag child mummy and Tin Hanakaten child have suggested that the Central Saharan peoples from the Epipaleolithic, Mesolithic, and Pastoral periods possessed dark skin complexions.<ref>{{cite book |last1=Soukopova |first1=Jitka |title=Round Heads: The Earliest Rock Paintings in the Sahara |date=16 January 2013 |publisher=Cambridge Scholars Publishing |isbn=978-1-4438-4579-3 |pages=19–24 |url=https://books.google.com/books?id=07wwBwAAQBAJ&q=Tuareg&pg=PR5 |language=en}}</ref> The creators of the Round Head rock art possessed dark skin.<ref>{{cite journal |last1=Soukopova |first1=Jitka |title=Saharan rock art sites as places for celebrating water |journal=Expression |date=June 2016 |url=https://www.academia.edu/28386236 |issn=2499-1341 |page=69}}</ref><ref>{{cite journal |last1=Soukopova |first1=Jitka |title=The Earliest Rock Paintings of the Central Sahara: Approaching Interpretation |journal=Time and Mind |date=2011 |volume=4 |issue=2 |pages=193–216 |doi=10.2752/175169711X12961583765333 }}</ref>

A 2025 study sequenced individuals from Takarkori (7,000 YBP) and discovered that most of their ancestry was from an unknown ancestral North African lineage, related to the African admixture component found in Iberomaurusians.<ref>{{Cite journal |last1=Salem |first1=Nada |last2=van de Loosdrecht |first2=Marieke S. |last3=Sümer |first3=Arev Pelin |last4=Vai |first4=Stefania |last5=Hübner |first5=Alexander |last6=Peter |first6=Benjamin |last7=Bianco |first7=Raffaela A. |last8=Lari |first8=Martina |last9=Modi |first9=Alessandra |last10=Al-Faloos |first10=Mohamed Faraj Mohamed |last11=Turjman |first11=Mustafa |last12=Bouzouggar |first12=Abdeljalil |last13=Tafuri |first13=Mary Anne |last14=Manzi |first14=Giorgio |last15=Rotunno |first15=Rocco |date=2 April 2025 |title=Ancient DNA from the Green Sahara reveals ancestral North African lineage |journal=Nature |volume=641 |issue=8061 |pages=144–150 |doi=10.1038/s41586-025-08793-7 |doi-access=free |pmid=40175549 |pmc=12043513 |bibcode=2025Natur.641..144S }}</ref> According to the study, the Takarkori people were distinct from both contemporary sub-Saharan Africans and non-Africans/Eurasians. They had "only a minor component of non-African ancestry" but did "not carry sub-Saharan African ancestry, suggesting that, contrary to previous interpretations, the Green Sahara was not a corridor connecting Northern and sub-Saharan Africa."<ref>Max Planck Institute. [https://www.eva.mpg.de/press/news/article/first-ancient-genomes-from-the-green-sahara-deciphered/ First ancient genomes from the Green Sahara deciphered]. 4 February 2025</ref> As per Johannes Krause of the Max Planck Institute, one of the authors of the study "The Takarkori lineage likely represents a remnant of the genetic diversity present in northern Africa between 50,000 and 20,000 years ago."<ref>{{cite news |title=Sahara desert, once lush and green, was home to mysterious human lineage |url=https://www.reuters.com/business/environment/sahara-desert-once-lush-green-was-home-mysterious-human-lineage-2025-04-04/ |work=Reuters |date=4 April 2025}}</ref>

thumb|left|E1b1b is the most common paternal haplogroup among countries on both sides of the Sahara, "Haplogroup E is defined by the M96 SNP (and others), for which a cautious reading of all of the evidence would indicate an eastern tropical African origin (Cruciani, 2007; Gomes et al., 2010; Trombetta et al., 2015)".<ref>{{cite book |last1=Holl |first1=Augustin |title=General history of Africa, IX: General history of Africa revisited |pages=511-531, 723-731|url=https://unesdoc.unesco.org/ark:/48223/pf0000396045?posInSet=1&queryId=N-EXPLORE-612fe50c-9ec6-4256-8bd3-7b7ec50033a7}}</ref>

In the Central Sahara, engraved and painted rock art were created perhaps as early as 10,000 years ago, spanning the Bubaline Period, Kel Essuf Period, Round Head Period, Pastoral Period, Caballine Period, and Cameline Period.<ref name="Soukopova">{{cite journal |last1=Soukopova |first1=Jitka |title=Central Saharan rock art: Considering the kettles and cupules |journal=Journal of Arid Environments |date=August 2017 |volume=143 |pages=10–14 |doi=10.1016/j.jaridenv.2016.12.011 |bibcode=2017JArEn.143...10S }}</ref> The Sahara was then a much wetter place than it is today. Over 30,000 petroglyphs of river animals such as crocodiles<ref name="Crocodiles">[http://news.nationalgeographic.com/news/2002/06/0617_020618_croc.html National Geographic News] {{Webarchive|url=https://web.archive.org/web/20180722011655/http://news.nationalgeographic.com/news/2002/06/0617_020618_croc.html |date=22 July 2018 }}, 17 June 2006.</ref> survive, with half found in the Tassili n'Ajjer in southeast Algeria. Fossils of dinosaurs,<ref name="2018_Dinosaur">{{cite news |title=Near-perfect fossils of Egyptian dinosaur discovered in the Sahara desert |journal=Nature Middle East |date=29 January 2018|doi=10.1038/nmiddleeast.2018.7 |last1=El-Said |first1=Mohammed }}</ref> including ''Afrovenator'', ''Jobaria'' and ''Ouranosaurus'', have also been found here. The modern Sahara, though, is not lush in vegetation, except in the Nile Valley, at a few oases, and in the northern highlands, where Mediterranean plants such as the olive tree are found to grow. Shifts in Earth's axis increased temperatures and decreased precipitation, which caused an abrupt beginning of North Africa desertification about 5,400 years ago.<ref name="Science Daily"/>

Accumulated sources of archaeological, genetic and anthropological evidence have confirmed early migratory flows and cultural influences from Sub-Saharan Africa into the Sahara and North African regions.<ref>"The period when sub-Saharan Africa was most influential in Egypt was a time when neither Egypt, as we understand it culturally, nor the Sahara, as we understand it geographically, existed. Populations and cultures now found south of the desert roamed far to the north. The culture of Upper Egypt, which became dynastic Egyptian civilization, could fairly be called a Sudanese transplant."{{cite book |last1=Vogel |first1=Joseph |title=Encyclopedia of precolonial Africa: archaeology, history, languages, cultures, and environments |date=1997 |publisher=AltaMira Press |location=Walnut Creek, Calif. |isbn=0-7619-8902-1 |pages=465–472}}</ref><ref>“The evidence for the basis of a root commonality is substantial. Specific prehistoric central African tool designs manifest themselves in Naqada, Badari, and Fayum sites (de Heinzelin 1962:109; Arkell and Ucko 1965:146, 150). Shaw (1976:156) states that "the early cultures of Merimde, the Fayum, Badari, Naqada I and II are essentially African and early African social customs and religious beliefs were the root and foundation of the ancient Egyptian way of life." Pottery usage probably spread from the central Saharan Highlands to the Nile Valley, as it seems to have been made there first (Flight 1973:554). The motifs of Saharan rock paintings show similarities to those in pharaonic art. This is probably due to the former influencing or being the progenitor of the latter (Mori 1964:230, 243, 244; Blanc 1964:183-184) via Saharans leaving a desiccating land to, in part, people the Nile Valley and other parts of Africa. The oldest mummy in Africa is of a black Saharan child (Donadoni 1964:185-188; Blanc 1964:184)”.{{cite journal |last1=Keita |first1=Shomarka O. Y. |title=royal incest and diffusion in Africa |journal=American Ethnologist |date=May 1981 |volume=8 |issue=2 |pages=392–393 |doi=10.1525/ae.1981.8.2.02a00120 }}</ref><ref>{{cite book |last1=Midant-Reynes |first1=Béatrix |title=The prehistory of Egypt: from the first Egyptians to the first pharaohs |date=2000 |publisher=Blackwell Publishers |location=Oxford, UK |isbn=0-631-21787-8 |pages=1–60}}</ref><ref>But the Saharan wet phase played a fundamental role in the origin of a widespread pastoral, cattle complex in northeast Africa, allowing both west-east and south-north interconnections and relationships to flourish. This widespread northeast African dynamic produced an interrelated set of cultural features out of which Egyptian Pharaonic civilization emerged. Similar features in modern Nilotic cattle cultures like the Shilluk, Dinka and Nuer can be seen not as “survivals” or coincidence, but shared traditions with common origins in the deep past."{{cite journal |last1=Smith |first1=Stuart Tyson |title=Gift of the Nile? Climate Change, the Origins of Egyptian Civilization and Its Interactions within Northeast Africa |journal=Across the Mediterranean – Along the Nile: Studies in Egyptology, Nubiology and Late Antiquity Dedicated to László Török. Budapest |date=1 January 2018 |url=https://www.academia.edu/43275151}}</ref><ref>p.44"Recent archaeological data provided the 1980s outline a new map of the formation of Ancient Egypt. Tasian (c.4500BC) and Badarin Nile Valley sites were not the centres of a Predynastic culture, but peripheral provinces of a network of earlier African cultures around which Badarian, Saharan, Nubian and Nilotic peoples regularly circulated (Darnell 2008)." p.46 - "The distribution of these linguistic data, as well as the archaeological data, notably the artefact and the word for the Egyptian w3s-sceptre, is consistent with the first sets of genetic findings: on the other hand, in Upper Egypt,'...the Gurna population has conserved the trace of an ancestral genetic structure from an ancestral East African population, characterized by a high M1 haplogroup frequency. The current structure of the Egyptian population may be the result of further of neighbouring populations on this ancestral population' (Stevanovitch et al.2004; for data fon another (ancient) Upper Egyptian populations, and its Sub-Sharan affinities, see Crubezy 1922)".{{cite book |last1=Anselin|first1=Alain |title="Some notes about an Early African Pool of Cultures" in Egypt in its African context: proceedings of the conference held at the Manchester Museum, University of Manchester, 2-4 October 2009 |date=2011 |publisher=Archaeopress |location=Oxford |isbn=978-1-4073-0760-2|pages=43–54}}</ref><ref>p.355 - "The importance of iconographic sources was emphasized in the main. Säve-Söderbergh and Leclant stressed that the links indicated by cave paintings between the vast expanses of the Sahara and the banks of the Nile nodded to a migration of peoples of the Sahara and groups from the South to the valley –something confirmed by research over the last thirty years. Diop set out to return Egypt to its southern African hinterland by systematically using Pharaonic statues and art to support his point of view. Although a debate on the north-south orientation of a 'civilizing' wave of peoples in the valley had prevailed up to that point, the avalanche of new data now made this idea redundant, suggesting instead the image of a growing and unifying political movement in the valley from south to north that repositioned its starting point back in time: in Upper Egypt, digs at the Uj tomb of King Scorpion at the Abydos necropolis push back the origin of the first Horus back to circa 3250 BCE, and the resumption of excavations at Nekhen led to the exhumation of the famous 'Elephant Kings' of Hierakonpolis (Nekhen) which have no inscriptions and date back even further to circa 3700 BCE." p.356 - "It quantified the key impact of sub-Saharan populations and found a clear link between the Siwi and the peoples of North-East Africa. We could continue with work by Zakrzewski on the predynastic population of Nekhen, investigations by Crubezy which traced the boundaries of the ancient Khoisan settlement to Upper Egypt, where its faint traces remain identifiable, and Keita's work, as the most groundbreaking."' p.356 - "Hence the work by Cerny's team highlighting the close links between the peoples of Upper Egypt, North Cameroon and Ethiopia – the Cameroon people living in the Mandara mountains speaking Chadic languages, and the Ethiopians speaking Kushitic languages, prior to Ge'ez being spread throughout the region during the Aksumite period. This broadens the linguistic debate to include language families that had been little studied or used in comparisons that have long focused on the East."{{cite book |last1=Anselin|first1=Alain |title= "Review of Ancient Civilizations of Africa: General History of Africa Volume II " in (General history of Africa, IX: General history of Africa revisited |pages=355–75|url=https://unesdoc.unesco.org/ark:/48223/pf0000396045?posInSet=1&queryId=N-EXPLORE-612fe50c-9ec6-4256-8bd3-7b7ec50033a7}}</ref> According to a number of genetic studies, the haplogroup E was found to have highest frequency and distribution across Africa, including supra-Saharan regions which encompass the Sahel along with the Horn of Africa and northern Saharan African countries such as Morocco and Mauritania.<ref>{{cite book |last1=Holl |first1=Augustin |title=The Genealogical Connections of Africa's Regions: The Y Chromosome Evidence in General history of Africa, IX: General history of Africa revisited |pages=511–531|url=https://unesdoc.unesco.org/ark:/48223/pf0000396045?posInSet=1&queryId=N-EXPLORE-612fe50c-9ec6-4256-8bd3-7b7ec50033a7}}</ref> The widespread presence of "P2/215/M35.1 (E1b1b), for short M35, likely also originated in eastern tropical Africa, and is predominantly distributed in an arc from the Horn of Africa up through Egypt".<ref>{{cite book |last1=Holl |first1=Augustin |title=The Genealogical Connections of Africa's Regions: The Y Chromosome Evidence in General history of Africa, IX: General history of Africa revisited |pages=511–531|url=https://unesdoc.unesco.org/ark:/48223/pf0000396045?posInSet=1&queryId=N-EXPLORE-612fe50c-9ec6-4256-8bd3-7b7ec50033a7}}</ref> The R haplogroup has also been identified to have high frequencies in central Saharan Africa, among some Afro-Asiatic and Nilo-Saharan language speaking groups.<ref>{{cite book |last1=Holl |first1=Augustin |title=The Genealogical Connections of Africa's Regions: The Y Chromosome Evidence in General history of Africa, IX: General history of Africa revisited |pages=511–531|url=https://unesdoc.unesco.org/ark:/48223/pf0000396045?posInSet=1&queryId=N-EXPLORE-612fe50c-9ec6-4256-8bd3-7b7ec50033a7}}</ref> In the view of biological anthropologist Shomarka Keita, associate of National Human Genome Center, the E haplogroup connects groups across both sides of the Saharan territories which undermines traditional 'racial' taxonomy associated with a 'white' northern Africa and 'black' southern Africa.<ref>{{cite book |last1=Holl |first1=Augustin |title=The Genealogical Connections of Africa's Regions: The Y Chromosome Evidence in General history of Africa, IX: General history of Africa revisited |pages=511–531|url=https://unesdoc.unesco.org/ark:/48223/pf0000396045?posInSet=1&queryId=N-EXPLORE-612fe50c-9ec6-4256-8bd3-7b7ec50033a7}}</ref> He further added that modern scholarship should abandon terms such as "North Africa" and "Sub-Saharan Africa" which "ignore diversity within the regions and come from a form of stereotyping racialist thought, and categorical thinking that stems from a section of older discourse."<ref>{{cite book |last1=Holl |first1=Augustin |title=General history of Africa, IX: General history of Africa revisited |pages=511–531|url=https://unesdoc.unesco.org/ark:/48223/pf0000396045?posInSet=1&queryId=N-EXPLORE-612fe50c-9ec6-4256-8bd3-7b7ec50033a7}}</ref>

===Kiffians=== The Kiffian culture is a prehistoric industry, or domain, that existed between 10,000 and 8,000 years ago in the Sahara, during the Neolithic Subpluvial. Human remains from this culture were found in 2000 at a site known as Gobero, located in Niger in the Ténéré Desert.<ref name="scidaily">{{cite web | url = https://www.sciencedaily.com/releases/2008/08/080815101317.htm | title = Stone Age Graveyard Reveals Lifestyles of A 'Green Sahara' | website = Science Daily | date = 15 August 2008 | access-date = 15 August 2008 | archive-date = 16 August 2008 | archive-url = https://web.archive.org/web/20080816060031/http://www.sciencedaily.com/releases/2008/08/080815101317.htm | url-status = live }}</ref> The site is known as the largest and earliest grave of Stone Age people in the Sahara.<ref name="nytimes">{{cite news | url = https://www.nytimes.com/2008/08/15/science/15sahara.html | title = Graves Found From Sahara's Green Period | first = John Noble | last = Wilford | newspaper = The New York Times | date = 14 August 2008 | access-date = 15 August 2008 | archive-date = 23 January 2012 | archive-url = https://web.archive.org/web/20120123154828/http://www.nytimes.com/2008/08/15/science/15sahara.html | url-status = live }}</ref> The Kiffians were skilled hunters. Bones of many large savannah animals that were discovered in the same area suggest that they lived on the shores of a lake that was present during the Holocene Wet Phase, a period when the Sahara was verdant and wet.<ref name="nytimes"/> The Kiffian people were tall, standing over six feet in height.<ref name="scidaily" /> Craniometric analysis indicates that this early Holocene population was closely related to the Late Pleistocene Iberomaurusians and early Holocene Capsians of the Maghreb, as well as mid-Holocene Mechta groups.<ref>{{cite journal|vauthors=Sereno PC, ((Garcea EAA)), Jousse H, Stojanowski CM, ((Saliège J-F)), Maga A|title=Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change|journal=PLOS ONE|date=2008|volume=3|issue=8|doi=10.1371/journal.pone.0002995|display-authors=etal|pmid=18701936|pmc=2515196|article-number=e2995|bibcode=2008PLoSO...3.2995S|doi-access=free}}</ref> Traces of the Kiffian culture do not exist after 8,000 years ago, as the Sahara went through a dry period for the next thousand years.<ref name="newscientist">{{cite magazine | url = https://www.newscientist.com/article/dn14536-stone-age-mass-graves-reveal-green-sahara.html?DCMP=ILC-hmts&nsref=news3_head_dn14536 | title = Stone Age mass graves reveal green Sahara | first = Nora | last = Schultz | magazine = New Scientist | date = 14 August 2008 | access-date = 15 August 2008}}</ref> After this time, the Tenerian culture colonized the area.

===Tenerians=== Gobero was discovered in 2000 during an archaeological expedition led by Paul Sereno, which sought dinosaur remains. Two distinct prehistoric cultures were discovered at the site: the early Holocene Kiffian culture, and the middle Holocene Tenerian culture. The post-Kiffian desiccation lasted until around 4600 BCE, when the earliest artefacts associated with the Tenerians have been dated to. Some 200 skeletons have been discovered at Gobero. The Tenerians were considerably shorter in height and less robust than the earlier Kiffians. Craniometric analysis also indicates that they were osteologically distinct. The Kiffian skulls are akin to those of the Late Pleistocene Iberomaurusians, early Holocene Capsians, and mid-Holocene Mechta groups, whereas the Tenerian crania are more like those of Mediterranean groups.<ref>{{cite journal|vauthors=Sereno PC, Garcea EA, Jousse H, Stojanowski CM, Saliège JF, Maga A |title=Lakeside Cemeteries in the Sahara: 5000 Years of Holocene Population and Environmental Change|journal=PLOS ONE|date=2008|volume=3|issue=8|doi=10.1371/journal.pone.0002995|display-authors=etal|pmid=18701936|pmc=2515196|article-number=e2995|bibcode=2008PLoSO...3.2995S|doi-access=free}}</ref><ref>{{cite news|last1=Wilford|first1=John Noble|title=In the Sahara, Stone Age graves from greener days|newspaper=The New York Times|url=https://www.nytimes.com/2008/08/14/health/14iht-15sahara.15304361.html?_r=0|access-date=10 June 2016|agency=The New York Times|date=14 August 2008|archive-date=8 March 2021|archive-url=https://web.archive.org/web/20210308154534/https://www.nytimes.com/2008/08/14/health/14iht-15sahara.15304361.html?_r=0|url-status=live}}</ref> Graves show that the Tenerians observed spiritual traditions, as they were buried with artifacts such as jewelry made of hippo tusks and clay pots. The most interesting find is a triple burial, dated to 5300 years ago, of an adult female and two children, estimated through their teeth as being five and eight years old, hugging each other. Pollen residue indicates they were buried on a bed of flowers. The three are assumed to have died within 24 hours of each other, but as their skeletons hold no apparent trauma (they did not die violently) and they have been buried so elaborately – unlikely if they had died of a plague – the cause of their deaths is a mystery. [[File:Vue de Taghit.jpg|thumb|Oued Zouzfana and village of Taghit]]

===Tashwinat Mummy=== Uan Muhuggiag appears to have been inhabited from at least the 6th millennium BCE to about 2700 BCE, although not necessarily continuously.<ref name="Mori-1998">{{cite book |last=Mori |first=F. |year=1998 |title=The Great Civilisations of the ancient Sahara: Neolithisation and the earliest evidence of anthropomorphic religions |location=Rome |publisher=L'Erma di Bretschneider |isbn=88-7062-971-6 }}</ref> The most noteworthy find at Uan Muhuggiag is the well-preserved mummy of a young boy of approximately {{frac|2|1|2}} years old. The child was in a fetal position, then embalmed, then placed in a sack made of antelope skin, which was insulated by a layer of leaves.<ref name="Hooke-2003">{{cite AV media |people=Hooke, C. (Director), & Mosely, G. (Producer) |date=2003 |title=Black Mummy of the Green Sahara |medium=Discovery Channel}}</ref> The boy's organs were removed, as evidenced by incisions in his stomach and thorax, and an organic preservative was inserted to stop his body from decomposing.<ref name="Cockburn-1980">{{cite book |last=Cockburn |first=A. |year=1980 |title=Mummies, Disease and Ancient Cultures |publisher=Cambridge University Press |isbn=0-521-23020-9 |url-access=registration |url=https://archive.org/details/mummiesdiseasean0000unse}}</ref> An ostrich eggshell necklace was also found around his neck.<ref name="Mori-1998" /> Radiocarbon dating determined the age of the mummy to be approximately 5600 years old, which makes it about 1000 years older than the earliest previously recorded mummy in ancient Egypt.<ref name="Temehu">{{cite web |title=Wan Muhuggiag |access-date=16 November 2015 |url=https://www.temehu.com/wan-muhuggiag.htm |archive-date=16 October 2015 |archive-url=https://web.archive.org/web/20151016012823/https://www.temehu.com/wan-muhuggiag.htm |url-status=live }}</ref> In 1958–59, an archaeological expedition led by Antonio Ascenzi conducted anthropological, radiological, histological and chemical analyses on the Uan Muhuggiag mummy. The team claimed that the mummy was a 30-month-old child of uncertain sex. They also found a long incision on the specimen's abdominal wall, which indicated that the body had been initially mummified by evisceration and later underwent natural desiccation. The team also stated that the mummy possessed "Negroid features."<ref name="Giuffra2010">{{cite journal |last1=V. Giuffra |display-authors=etal |date=2010 |title=Antonio Ascenzi (1915–2000), a Pathologist devoted to Anthropology and Paleopathology |url=http://www.pathologica.it/wp-content/uploads/2014/10/PATHOLOGICA_1-10.pdf#9 |journal=Pathologica |volume=102 |issue=1 |pages=1–5 |pmid=20731247 |archive-url=https://web.archive.org/web/20161125045252/http://www.pathologica.it/wp-content/uploads/2014/10/PATHOLOGICA_1-10.pdf#9 |archive-date=25 November 2016 |access-date=24 November 2016}}</ref> However, modern genetics has since proven that the final claim is unscientific and not supported by evidence.<ref>Templeton, A. (2016). "Evolution and Notions of Human Race". In Losos, J.; Lenski, R. (eds.). ''How Evolution Shapes Our Lives: Essays on Biology and Society''. Princeton; Oxford: Princeton University Press. pp. 346–361. doi:[https://www.jstor.org/stable/j.ctv7h0s6j?turn_away=true 10.2307/j.ctv7h0s6j.26] {{Webarchive|url=https://web.archive.org/web/20211127055407/https://www.jstor.org/stable/j.ctv7h0s6j?turn_away=true |date=27 November 2021 }}</ref><ref>American Association of Physical Anthropologists (27 March 2019). "[https://physanth.org/about/position-statements/aapa-statement-race-and-racism-2019/ AAPA Statement on Race and Racism] {{Webarchive|url=https://web.archive.org/web/20200322034009/https://physanth.org/about/position-statements/aapa-statement-race-and-racism-2019/ |date=22 March 2020 }}". ''American Association of Physical Anthropologists''. Retrieved 27 November 2021</ref> A more recent publication referenced a laboratory examination of the cutaneous features of the child mummy in which the results verified that the child possessed a dark skin complexion.<ref>{{cite book |last1=Soukopova |first1=Jitka |title=Round Heads: The Earliest Rock Paintings in the Sahara |date=16 January 2013 |publisher=Cambridge Scholars Publishing |isbn=978-1-4438-4579-3 |pages=19–24 |url=https://books.google.com/books?id=07wwBwAAQBAJ&q=Tuareg&pg=PR5 |language=en |access-date=6 April 2023 |archive-date=30 July 2023 |archive-url=https://web.archive.org/web/20230730165722/https://books.google.com/books?id=07wwBwAAQBAJ&q=Tuareg&pg=PR5 |url-status=live }}</ref> One other individual, an adult, was found at Uan Muhuggiag, buried in a crouched position.<ref name="Mori-1998" /> However, the body showed no evidence of evisceration or any other method of preservation. The body was estimated to date from about 7500 BP.<ref name="Soukopova-2012">{{cite book |last=Soukopova |first=J. |year=2012 |title=Round Heads: The Earliest Rock Paintings in the Sahara |location=Newcastle upon Tyne |publisher=Cambridge Scholars Publishing |isbn=978-1-4438-4007-1}}</ref>

===Nubians=== {{further|Sahara pump theory|Neolithic Subpluvial}} [[File:Beni-Izguen.jpg|thumb|Beni Isguen, a holy city surrounded by thick walls in the Algerian Sahara]] During the Neolithic Era, before the onset of desertification around 9500 BCE, the central Sudan had been a rich environment supporting a large population ranging across what is now barren desert, like the Wadi el-Qa'ab. By the 5th millennium BCE, the people who inhabited what is now called Nubia were full participants in the "agricultural revolution", living a settled lifestyle with domesticated plants and animals. Saharan rock art of cattle and herdsmen suggests the presence of a cattle cult like those found in Sudan and other pastoral societies in Africa today.<ref>{{cite web |url=http://www.anth.ucsb.edu/faculty/stsmith/research/nubia_history.html |title=History of Nubia |publisher=Anth.ucsb.edu |access-date=12 June 2010 |archive-date=21 June 2010 |archive-url=https://web.archive.org/web/20100621115727/http://www.anth.ucsb.edu/faculty/stsmith/research/nubia_history.html |url-status=live }}</ref>

Megaliths found at Nabta Playa are overt examples of probably the world's first known archaeoastronomy devices, predating Stonehenge by some 2,000 years.<ref>[https://web.archive.org/web/20130725174732/http://www.planetquest.org/learn/nabta.html The History of Astronomy]. PlanetQuest</ref> This complexity, as observed at Nabta Playa, and as expressed by different levels of authority within the society there, likely formed the basis for the structure of both the Neolithic society at Nabta and the Old Kingdom of Egypt.<ref>Wendorf, Fred (1998) [https://web.archive.org/web/20101009235228/http://www.comp-archaeology.org/WendorfSAA98.html Late Neolithic megalithic structures at Nabta Playa].</ref>

Archaeological evidence has attested that population settlements occurred in Nubia as early as the Late Pleistocene era and from the 5th millennium BCE onwards, whereas there is "no or scanty evidence" of human presence in the Egyptian Nile Valley during these periods, which may be due to problems in site preservation.<ref>{{cite web |last1=Gatto |first1=Maria C. |title=The Nubian Pastoral Culture as Link between Egypt and Africa: A View from the Archaeological Record |url=https://www.academia.edu/545582 |access-date=24 June 2022 |archive-date=10 May 2022 |archive-url=https://web.archive.org/web/20220510233717/https://www.academia.edu/545582 |url-status=live }}</ref>

===Egyptians=== {{further|Northeast Africa|Predynastic Egypt|North Africa}} [[File:Bestias11.JPG|thumb|left|Neolithic rock art, over 7,000 years old, Cave of Beasts, Egypt]]

By 6000 BCE predynastic Egyptians in the southwestern corner of Egypt were herding cattle and constructing large buildings. Subsistence in organized and permanent settlements in predynastic Egypt by the middle of the 6th millennium BCE centered predominantly on cereal and animal agriculture: cattle, goats, pigs and sheep. Metal objects replaced prior ones of stone. Tanning of animal skins, pottery and weaving were commonplace in this era also. There are indications of seasonal or only temporary occupation of the Al Fayyum in the 6th millennium BCE, with food activities centering on fishing, hunting and food-gathering. Stone arrowheads, knives and scrapers from the era are commonly found.<ref name= Fayum>[http://www.digitalegypt.ucl.ac.uk/fayum/fayumb.html Fayum, Qarunian] {{Webarchive|url=https://web.archive.org/web/20071105200210/http://www.digitalegypt.ucl.ac.uk/fayum/fayumb.html |date=5 November 2007 }} (Fayum B, about 6000–5000 BCE?), [http://www.digitalegypt.ucl.ac.uk Digital Egypt] {{Webarchive|url=https://web.archive.org/web/20100416080018/http://www.digitalegypt.ucl.ac.uk/ |date=16 April 2010 }}.</ref> Burial items included pottery, jewelry, farming and hunting equipment, and assorted foods including dried meat and fruit. Burial in desert environments appears to enhance Egyptian preservation rites, and the dead were buried facing due west.<ref name= Predynastic>Predynastic (5,500–3,100 BCE), Tour Egypt.</ref>

Several scholars have argued that the African origins of the Egyptian civilisation derived from pastoral communities which emerged in both the Egyptian and Sudanese regions of the Nile Valley in the fifth millennium BCE.<ref>{{cite journal |last1=Wengrow |first1=David |last2=Dee |first2=Michael |last3=Foster |first3=Sarah |last4=Stevenson |first4=Alice |last5=Ramsey |first5=Christopher Bronk |title=Cultural convergence in the Neolithic of the Nile Valley: a prehistoric perspective on Egypt's place in Africa |journal=Antiquity |date=March 2014 |volume=88 |issue=339 |pages=95–111 |doi=10.1017/S0003598X00050249 |doi-access=free }}</ref> According to UNESCO scholar, Alain Anselin, recent data "over the last thirty years" have confirmed the migration of peoples from the Sahara and south of Egypt into the Nile Valley during the early, formative period.<ref name="General history of Africa, IX: Gene">{{cite book |last1=Holl |first1=Augustin |title=General history of Africa, IX: General history of Africa revisited |pages=355–375|url=https://unesdoc.unesco.org/ark:/48223/pf0000396045?posInSet=1&queryId=N-EXPLORE-612fe50c-9ec6-4256-8bd3-7b7ec50033a7}}</ref>

Archaeologist, Fekri Hassan, (2002) indicated that the megalithic monuments in the Saharan region of Niger and the Eastern Sahara which developed, as early as 4700 BCE, may have served as antecedents for the mastabas and pyramids of ancient Egypt.<ref> p.17 - "During Predynastic Egypt, tumuli were present at various locations (e.g., Naqada, Helwan). The appearance of megalithic monumental tombs and tumuli in the Nigerian Sahara as early as 4700 BC, and presumably much earlier in the Eastern Sahara (Wendorf et al., 1992/3), clearly predates the construction of Egyptian mastabas and pyramids by a very long time. Such structures might have been the precursors of Egyptian pyramids and monumental architecture. It is noteworthy that tumuli appear in Egypt in several localities, such as at Nagada and Helwan, during Predynastic times (Hassan, 1988)." {{cite book |last1=Hassan |first1=F. A. |title=Droughts, Food and Culture |chapter=Palaeoclimate, Food and Culture Change in Africa: An Overview |date=2002 |pages=11–26 |doi=10.1007/0-306-47547-2_2 |isbn=0-306-46755-0 }}</ref>

By 3400 BCE, the Sahara was as dry as it is today, due to reduced precipitation and higher temperatures resulting from a shift in Earth's orbit.<ref name = "Science Daily"/> As a result of this aridification, it became a largely impenetrable barrier to humans, with the remaining settlements mainly being concentrated around the numerous oases that dot the landscape. Little trade or commerce is known to have passed through the interior in subsequent periods, the only major exception being the Nile Valley. The Nile, however, was impassable at several cataracts, making trade and contact by boat difficult.

===Haratins===

The Haratin speak Maghrebi Arabic dialects and Berber languages.<ref>{{cite book |last1=Shoup |first1=John A. |title=Ethnic Groups of Africa and the Middle East: An Encyclopedia |date=17 October 2011 |publisher=Bloomsbury Publishing USA |isbn=979-8-216-08131-9 |pages=114–116 |url=https://books.google.com/books?id=uLD2EAAAQBAJ&dq=Haratin+dialects&pg=PT160 |language=en}}</ref> They are believed to largely descend from native ancient black populations that inhabited the Sahara.<ref name=":1">{{cite journal |last1=Keita |first1=S. O. Y. |date=1993 |title=Studies and Comments on Ancient Egyptian Biological Relationships |journal=History in Africa |volume=20 |pages=140 |doi=10.2307/3171969 |jstor=3171969 |quote=Paoli (1972) found dynastic mummies to have ABO frequencies most like those of the northern Haratin, a group believed to be largely descended from the ancient Saharans.}}</ref><ref name=":2">{{Cite book |last=Batran |first=Aziz Abdallah |chapter-url=https://books.google.com/books?id=HVGRAgAAQBAJ&dq=haratin%20black%20populations%20sahara&pg=PA4 |title=Slaves and Slavery in Africa: Volume Two: The Servile Estate |date=1985 |publisher=Routledge |isbn=978-1-135-78016-6 |editor-last=Willis |editor-first=John Ralph |language=en |chapter=The ‘Ulama’ of Fas, Mulay Isma‘il and the Issue of the Haratin of Fas |quote=Although the origin of the Haratin is shrouded in mystery, it is generally believed that they were indigenous to the north Saharan oases, hybrids between an ancient black population and Berbers, and most of them had dark skin and negroid features. The Haratin did not constitute a tribe, rather they were groups of families scattered amongst North African and Saharan Arab and Berber tribes. Though the Haratin were free men, they were generally considered to be of inferior social status, between slaves and free men (hur thani). Most of the Haratin were farmworkers and not landowners, receiving a fifth (Khammas) of the harvest from Arab and Berber landlords, for their work. In general, the Haratin were a class of people "who were in many ways like slaves: i.e. non-tribal, economically vulnerable, socially debased and pheno-typically distinct."}}</ref><ref>"With the spectacular evolution of genetic analysis methods in recent years (particularly with regard to DNA), it is now possible to evaluate in an increasingly precise way the specific and original characteristics of these populations, which for too long have been considered as a by-product of slavery when they are one of the oldest components of the Saharan population." {{cite journal |last1=Gast |first1=M. |title=Harṭâni |journal=Encyclopédie Berbère |date=2000 |volume=22 |pages=3414–3420 |doi=10.4000/encyclopedieberbere.1704 }}</ref>

Historically, it was commonly believed that the Haratins were entirely descended from Sub-Saharan slaves, but they also are descendants from groups native to southern Morocco<ref>{{cite book |last1=Hamel |first1=Chouki |title=Diasporic Africa |chapter=Blacks and Slavery in Morocco: The Question of the Haratin at the End of the Seventeenth Century |date=2022 |pages=177–199 |doi=10.18574/nyu/9780814733226.003.0012 |chapter-url={{GBurl|9PhJYtVQCWEC|p=177}} |isbn=978-0-8147-3322-6 }}</ref> and the northern Sahara.<ref name=":1">{{cite journal |last1=Keita |first1=S. O. Y. |date=1993 |title=Studies and Comments on Ancient Egyptian Biological Relationships |journal=History in Africa |volume=20 |pages=140 |doi=10.2307/3171969 |jstor=3171969 |quote=Paoli (1972) found dynastic mummies to have ABO frequencies most like those of the northern Haratin, a group believed to be largely descended from the ancient Saharans.}}</ref><ref name=":2">{{Cite book |last=Batran |first=Aziz Abdallah |chapter-url=https://books.google.com/books?id=HVGRAgAAQBAJ&dq=haratin%20black%20populations%20sahara&pg=PA4 |title=Slaves and Slavery in Africa: Volume Two: The Servile Estate |date=1985 |publisher=Routledge |isbn=978-1-135-78016-6 |editor-last=Willis |editor-first=John Ralph |language=en |chapter=The ‘Ulama’ of Fas, Mulay Isma‘il and the Issue of the Haratin of Fas |quote=Although the origin of the Haratin is shrouded in mystery, it is generally believed that they were indigenous to the north Saharan oases, hybrids between an ancient black population and Berbers, and most of them had dark skin and negroid features. The Haratin did not constitute a tribe, rather they were groups of families scattered amongst North African and Saharan Arab and Berber tribes. Though the Haratin were free men, they were generally considered to be of inferior social status, between slaves and free men (hur thani). Most of the Haratin were farmworkers and not landowners, receiving a fifth (Khammas) of the harvest from Arab and Berber landlords, for their work. In general, the Haratin were a class of people "who were in many ways like slaves: i.e. non-tribal, economically vulnerable, socially debased and pheno-typically distinct."}}</ref> French academic André Adam attributed their origin mostly to inhabitants of the Sahara.<ref>{{cite book |last1=Mohamed |first1=Mohamed Hassan |title=Between Caravan and Sultan: The Bayruk of Southern Morocco: A Study in History and Identity |date=22 February 2012 |publisher=BRILL |isbn=978-90-04-18379-7 |page=189 |url=https://books.google.com/books?id=Gy3s6zd-yTcC |language=en}}</ref>

===Tichitt culture===

In 4000 BCE, the start of sophisticated social structure (e.g., trade of cattle as valued assets) developed among herders amid the Pastoral Period of the Sahara.<ref name="Brass3">{{cite journal |last1=Brass |first1=Michael |title=The Emergence of Mobile Pastoral Elites during the Middle to Late Holocene in the Sahara |journal=Journal of African Archaeology |date=2019 |volume=17 |pages=53–75 |doi=10.1163/21915784-20190003 }}</ref> Saharan pastoral culture (e.g., fields of tumuli, lustrous stone rings, axes) was intricate.<ref name="Brass II">{{cite journal |last1=Brass |first1=Michael |title=Reconsidering the emergence of social complexity in early Saharan pastoral societies, 5000 – 2500 B.C. |journal=Sahara (Segrate, Italy) |year=2007 |volume=18 |pages=7–22 |publisher=Sahara (Segrate)|pmid=24089595 |pmc=3786551 }}</ref> By 1800 BCE, Saharan pastoral culture expanded throughout the Saharan and Sahelian regions.<ref name="Brass3" /> The initial stages of sophisticated social structure among Saharan herders served as the segue for the development of sophisticated hierarchies found in African settlements, such as Dhar Tichitt.<ref name="Brass3" /> After migrating from the Central Sahara, proto-Mande peoples established their civilization in the Tichitt region<ref name="Abd-El-Moniem" /> of the Western Sahara.<ref name="Kea">{{cite journal |last1=Kea |first1=Ray A. |title=Expansions and Contractions: World-Historical Change and the Western Sudan World-System (1200/1000 B.C. – 1200/1250 A.D.) |journal=Journal of World-Systems Research |date=2004 |pages=723–816 |doi=10.5195/jwsr.2004.286 }}</ref> The Tichitt Tradition of eastern Mauritania dates from 2200 BCE<ref name="McDougall">{{cite book |last1=McDougall |first1=E Ann |title=Oxford Research Encyclopedia of African History |chapter=Saharan Peoples and Societies |date=2019 |doi=10.1093/acrefore/9780190277734.013.285 |isbn=978-0-19-785172-2 }}</ref><ref name="Holl">{{cite journal |last1=Holl |first1=Augustin F.C. |title=Coping with uncertainty: Neolithic life in the Dhar Tichitt-Walata, Mauritania, (ca. 4000–2300 BP) |journal=Comptes Rendus. Géoscience |date=25 June 2009 |volume=341 |issue=8–9 |pages=703–712 |doi=10.1016/j.crte.2009.04.005 |bibcode=2009CRGeo.341..703H }}</ref> to 200 BCE.<ref name="MacDonald IV">{{cite book |last1=MacDonald |first1=K. |last2=Vernet |first2=R. |title=Early domesticated pearl millet in Dhar Nema (Mauritania): evidence of crop processing waste as ceramic temper |date=2007 |publisher=Barkhuis |location=Netherlands |pages=71–76 |isbn=978-90-77922-30-9 |url=https://books.google.com/books?id=gTnffH-elc0C&q=%22Tichitt%22+%22metallurgy%22&pg=PA71 |access-date=24 May 2021 |archive-date=30 July 2023 |archive-url=https://web.archive.org/web/20230730165659/https://books.google.com/books?id=gTnffH-elc0C&q=%22Tichitt%22+%22metallurgy%22&pg=PA71 |url-status=live }}</ref><ref name="Kay">{{cite journal |last1=Kay |first1=Andrea U. |last2=Fuller |first2=Dorian Q. |last3=Neumann |first3=Katharina |last4=Eichhorn |first4=Barbara |last5=Höhn |first5=Alexa |last6=Morin-Rivat |first6=Julie |last7=Champion |first7=Louis |last8=Linseele |first8=Veerle |last9=Huysecom |first9=Eric |last10=Ozainne |first10=Sylvain |last11=Lespez |first11=Laurent |last12=Biagetti |first12=Stefano |last13=Madella |first13=Marco |last14=Salzmann |first14=Ulrich |last15=Kaplan |first15=Jed O. |title=Diversification, Intensification and Specialization: Changing Land Use in Western Africa from 1800 BC to AD 1500 |journal=Journal of World Prehistory |date=2019 |volume=32 |issue=2 |pages=179–228 |doi=10.1007/s10963-019-09131-2 |bibcode=2019JWPre..32..179K |hdl=10261/181848 |hdl-access=free }}</ref> Tichitt culture, at Dhar Néma, Dhar Tagant, Dhar Tichitt, and Dhar Walata, included a four-tiered hierarchal social structure, farming of cereals, metallurgy, numerous funerary tombs, and a rock art tradition.<ref name="Sterry">{{cite book |last1=Sterry |first1=Martin |last2=Mattingly |first2=David J. |title=Urbanisation and State Formation in the Ancient Sahara and Beyond |date=26 March 2020 |publisher=Cambridge University Press |page=318 |isbn=978-1-108-49444-1 |url=https://books.google.com/books?id=B9PKDwAAQBAJ&q=%22Tichitt+culture%22&pg=PR8 |access-date=24 May 2021 |archive-date=30 July 2023 |archive-url=https://web.archive.org/web/20230730165659/https://books.google.com/books?id=B9PKDwAAQBAJ&q=%22Tichitt+culture%22&pg=PR8 |url-status=live }}</ref> At Dhar Tichitt and Dhar Walata, pearl millet may have also been independently tamed amid the Neolithic.<ref name="Champion">{{cite journal |last1=Champion |first1=Louis |display-authors=etal |title=Agricultural diversification in West Africa: an archaeobotanical study of the site of Sadia (Dogon Country, Mali) |journal=Archaeological and Anthropological Sciences |year=2021 |volume=13 |issue=4 |article-number=60 |doi=10.1007/s12520-021-01293-5 |pmid=33758626 |pmc=7937602 |bibcode=2021ArAnS..13...60C }}</ref> Dhar Tichitt, which includes Dakhlet el Atrouss, may have served as the primary regional center for the multi-tiered hierarchical social structure of the Tichitt Tradition,<ref name="Linares-Matás">{{cite journal |last1=Linares-Matás |first1=Gonzalo J. |title=Spatial Organization and Socio-Economic Differentiation at the Dhar Tichitt Center of Dakhlet el Atrouss I (Southeastern Mauritania) |journal=African Archaeological Review |date=13 April 2022 |volume=39 |issue=2 |pages=167–188 |doi=10.1007/s10437-022-09479-5 |doi-access=free}}</ref> and the Malian Lakes Region, which includes Tondidarou, may have served as a second regional center of the Tichitt Tradition.<ref name="Vernet">{{cite journal |last1=Vernet |first1=Robert |last2=Gestrich |first2=Nikolas |last3=Coutros |first3=Peter R. |title=The Tichitt Culture and the Malian Lakes Region |journal=African Archaeological Review |date=27 September 2023 |volume=40 |issue=4 |pages=761–773 |doi=10.1007/s10437-023-09554-5 |doi-access=free }}</ref> The urban<ref name="Kea" /> Tichitt Tradition may have been the earliest large-scale, complexly organized society in West Africa,<ref name="MacDonald II" /> and an early civilization of the Sahara,<ref name="Abd-El-Moniem">{{cite web |last1=Abd-El-Moniem |first1=Hamdi Abbas Ahmed |title=A New Recording of Mauritanian Rock Art |url=https://discovery.ucl.ac.uk/id/eprint/1444476/1/U591781.pdf |website=University College London |access-date=24 May 2021 |archive-date=31 August 2021 |archive-url=https://web.archive.org/web/20210831212222/https://discovery.ucl.ac.uk/id/eprint/1444476/1/U591781.pdf |url-status=live }}</ref><ref name="McDougall" /> which may have served as the segue for state formation in West Africa.<ref name="Brass II" />

As areas where the Tichitt cultural tradition were present, Dhar Tichitt and Dhar Walata were occupied more frequently than Dhar Néma.<ref name="MacDonald II">{{cite journal |last1=MacDonald |first1=Kevin C. |last2=Vernet |first2=Robert |last3=Martinón-Torres |first3=Marcos |last4=Fuller |first4=Dorian Q. |title=Dhar Néma: From early agriculture to metallurgy in southeastern Mauritania |journal=Azania: Archaeological Research in Africa |date=2009 |volume=44 |pages=3–48 |doi=10.1080/00671990902811330 }}</ref> Farming of crops (e.g., millet) may have been a feature of the Tichitt cultural tradition as early as 3rd millennium BCE in Dhar Tichitt.<ref name="MacDonald II" />

As part of a broader trend of iron metallurgy developed in the West African Sahel amid 1st millennium BCE, iron items (350 BCE – 100 CE) were found at Dhar Tagant, iron metalworking and/or items (800 BCE – 400 BCE) were found at Dia Shoma and Walaldé, and the iron remnants (760 BCE – 400 BCE) found at Bou Khzama and Djiganyai.<ref name="MacDonald II" /> The iron materials that were found are evidence of iron metalworking at Dhar Tagant.<ref name="Kay"/> In the late period of the Tichitt Tradition at Dhar Néma, tamed pearl millet was used to temper the tuyeres of an oval-shaped low shaft furnace; this furnace was one out of 16 iron furnaces located on elevated ground.<ref name="MacDonald IV" /> Iron metallurgy may have developed before the second half of 1st millennium BCE, as indicated by pottery dated between 800 BCE and 200 BCE.<ref name="MacDonald IV" /> At Dhar Walata and Dhar Tichitt, copper was also used.<ref name="Kea" />

After its decline in Mauritania, the Tichitt Tradition spread to the Middle Niger region (e.g., Méma, Macina, Dia Shoma, Jenne Jeno) of Mali where it developed into and persisted as Faïta Facies ceramics between 1300 BCE and 400 BCE among rammed earth architecture and iron metallurgy (which had developed after 900 BCE).<ref name="MacDonald2">{{cite web |last1=MacDonald |first1=K.C. |title=Betwixt Tichitt and the IND: the pottery of the Faita Facies, Tichitt Tradition |url=https://dokumen.tips/documents/betwixt-tichitt-and-the-ind-the-pottery-of-the-faita-facies-tichitt-tradition.html |website=Dokumen |publisher=Azania: Archaeological Research in Africa |access-date=24 May 2021 |archive-date=13 May 2021 |archive-url=https://web.archive.org/web/20210513131447/https://dokumen.tips/documents/betwixt-tichitt-and-the-ind-the-pottery-of-the-faita-facies-tichitt-tradition.html |url-status=live }}</ref> Thereafter, the Ghana Empire developed in the 1st millennium CE.<ref name="MacDonald2" />

===Phoenicians=== {{Further|History of Western Sahara}} [[File:Bilma-Salzkarawane1.jpg|thumb|Azalai salt caravan. The French reported that the 1906 caravan numbered 20,000 camels.]]

The people of Phoenicia, who flourished from 1200 to 800 BCE, created a chain of settlements along the coast of North Africa and traded extensively with its inhabitants. This put them in contact with the people of ancient Libya, who were the ancestors of people who speak Berber languages in North Africa and the Sahara today.

The Libyco-Berber alphabet of the ancient Libyans of north Africa seems to have been based on Phoenician, and its descendant Tifinagh is still used today by the (Berber) Tuareg of the central Sahara.

The Periplus of the Phoenician navigator Hanno, who lived sometime in the 5th century BCE, claims that he founded settlements along the Atlantic coast of Africa, possibly including the Western Sahara. The identification of the places discussed is controversial, and archeological confirmation is lacking.

===Greeks=== By 500 BCE, Greeks arrived in the desert. Greek traders spread along the eastern coast of the desert, establishing trading colonies along the Red Sea. The Carthaginians explored the Atlantic coast of the desert, but the turbulence of the waters and the lack of markets caused a lack of presence further south than modern Morocco. Centralized states thus surrounded the desert on the north and east; it remained outside the control of these states. Raids from the nomadic Berber people of the desert were of constant concern to those living on the edge of the desert.

===Garamantes=== [[File:Ghardaia01.jpg|thumb|Market on the main square of Ghardaïa (1971)]]

An urban civilization, the Garamantes, arose around 500 BCE in the Sahara, in a valley that is now called the Wadi al-Ajal in Fezzan, Libya.<ref name="Lakes"/> The Garamantes built a prosperous empire in the heart of the desert.<ref>Mattingly et al. (2003). ''Archaeology of Fazzan'', Volume 1</ref> The Garamantes achieved this development by digging tunnels far into the mountains flanking the valley to tap fossil water and bring it to their fields. The Garamantes grew populous and strong, conquering their neighbors, and capturing and enslaving many individuals who were forced to work by extending the tunnels. The ancient Greeks and the Romans knew of the Garamantes and regarded them as uncivilized nomads. However, they traded with them, and a Roman bath has been found in the Garamantes' capital of Garama. Archaeologists have found eight major towns and many other important settlements in the Garamantes' territory. The Garamantes' civilization eventually collapsed after they had depleted available water in the aquifers and could no longer sustain the effort to extend the tunnels further into the mountains.<ref name = "Keys">{{cite magazine|author=Keys, David|year= 2004|title= Kingdom of the Sands|magazine=Archaeology|volume= 57 |issue= 2|url=https://archive.archaeology.org/0403/abstracts/sands.html}}</ref>

Between the first century BCE and the fourth century CE, several Roman expeditions into the Sahara were conducted by groups of military and commercial units of Romans.

===Islamic and Arabic expansion=== {{main|Trans-Saharan trade|Islamization of Sudan}} The Byzantine Empire ruled the northern shores of the Sahara from the 5th to the 7th centuries. After the Muslim conquest of Arabia, specifically the Arabian peninsula, the Muslim conquest of North Africa began in the mid-7th to early 8th centuries and Islamic influence expanded rapidly on the Sahara. By the end of 641 all of Egypt was in Muslim hands. Trade across the desert intensified, and a significant slave trade crossed the desert. It has been estimated that from the 10th to 19th centuries some 6,000 to 7,000 slaves were transported north each year.<ref>Fage, J.D. (2001) ''A History of Africa''. Routledge, 4th ed. {{ISBN|0-415-25248-2}}. p. 256</ref>

The Beni Ḥassān and other nomadic Arab tribes dominated the Sanhaja Berber tribes of the western Sahara after the Char Bouba war of the 17th century. As a result, Arabian culture and language came to dominate, and the Berber tribes underwent some Arabization.

===Ottoman Turkish era=== [[File:Tuarick in a Shirt of Leather, Tuarick of Aghades.jpg|thumb|right|The Tuareg controlled the central Sahara and its trade, by George Francis Lyon, 1821]] In the 16th century the northern fringe of the Sahara, such as coastal regencies in present-day Algeria and Tunisia, as well as some parts of present-day Libya, together with the semi-autonomous kingdom of Egypt, were occupied by the Ottoman Empire. From 1517 Egypt was a valued part of the Ottoman Empire, ownership of which provided the Ottomans with control over the Nile Valley, the east Mediterranean and North Africa. The benefit of the Ottoman Empire was the freedom of movement for citizens and goods. Traders exploited the Ottoman land routes to handle the spices, gold and silk from the East, manufactured goods from Europe, and the slave and gold traffic from Africa. Arabic continued as the local language and Islamic culture was much reinforced. The Sahel and southern Sahara regions were home to several independent states or to roaming Tuareg clans.

===European colonialism=== European colonialism in the Sahara began in the 19th century. France conquered the regency of Algiers from the Ottomans in 1830, and French rule spread south from French Algeria and eastwards from Senegal into the upper Niger to include present-day Algeria, Chad, Mali then French Sudan including Timbuktu (1893), Mauritania, Morocco (1912), Niger, and Tunisia (1881). By the beginning of the 20th century, the trans-Saharan trade had clearly declined because goods were moved through more modern and efficient means, such as airplanes, rather than across the desert.<ref>Trans-Saharan Africa in World History, Ch. 6, Ralph Austin</ref>

The French took advantage of long-standing animosity between the Chaamba Arabs and the Tuareg. The newly raised ''Méhariste'' camel corps were originally recruited mainly from the Chaamba nomadic tribe. In 1902, the French penetrated the Hoggar Mountains and defeated Ahaggar Tuareg in the battle of Tit. [[File:Scramble-for-Africa-1880-1913.png|thumb|The French colonial empire (blue) was the dominant presence in the Sahara.]] The French Colonial Empire was the dominant presence in the Sahara. It established regular air links from Toulouse (HQ of famed Aéropostale), to Oran and over the Hoggar to Timbuktu and West to Bamako and Dakar, as well as trans-Sahara bus services run by La Compagnie Transsaharienne (est. 1927).<ref name=wauthier1>{{cite web | url = http://saharayro.free.fr/fwauthier1.htm | title = Wauthier Bréard 1933 | access-date = 22 February 2013 | language = fr | archive-date = 13 April 2021 | archive-url = https://web.archive.org/web/20210413062745/http://saharayro.free.fr/fwauthier1.htm | url-status = live }}</ref> A remarkable film shot by famous aviator Captain René Wauthier in 1933 documents the first crossing by a large truck convoy from Algiers to Tchad, across the Sahara.<ref name=Reconnaissance_saharienne>{{cite web|last=Wauthier|first=René|title=Reconnaissance saharienne|url=http://www.cnc-aff.fr/internet_cnc/Internet/ARemplir/Fiches/Corpus_Algerie/decouverte/46506.html|work=French Cinema Archives|access-date=22 February 2013|language=fr}}</ref>{{New archival link needed|date=April 2026}}

Egypt, under Muhammad Ali and his successors, conquered Nubia in 1820–22, founded Khartoum in 1823, and conquered Darfur in 1874. Egypt, including Sudan, became a British protectorate in 1882. Egypt and Britain lost control of the Sudan from 1882 to 1898 as a result of the Mahdist War. After its capture by British troops in 1898, the Sudan became an Anglo-Egyptian condominium.

Spain captured present-day Western Sahara after 1874, although Rio del Oro remained largely under Sahrawi influence. In 1912, Italy captured parts of what was to be named Libya from the Ottomans. To promote the Roman Catholic religion in the desert, Pope Pius IX appointed a delegate Apostolic of the Sahara and the Sudan in 1868; later in the 19th century his jurisdiction was reorganized into the Vicariate Apostolic of Sahara.

===Breakup of the empires and afterwards=== thumb|A natural rock arch in south western Libya

Egypt became independent of Britain in 1936, although the Anglo-Egyptian treaty of 1936 allowed Britain to keep troops in Egypt and to maintain the British-Egyptian condominium in the Sudan. British military forces were withdrawn in 1954.

Most of the Saharan states achieved independence after World War II: Libya in 1951; Morocco, Sudan, and Tunisia in 1956; Chad, Mali, Mauritania, and Niger in 1960; and Algeria in 1962. Spain withdrew from Western Sahara in 1975, and it was partitioned between Mauritania and Morocco. Mauritania withdrew in 1979; Morocco continues to hold the territory (see Western Sahara conflict).<ref>{{cite news |title=Algeria recalls envoy to Morocco in row over Western Sahara |url=https://www.aljazeera.com/news/2021/7/18/algeria-recalls-envoy-to-morocco-in-row-over-western-sahara |work=Al-Jazeera |date=18 July 2021 |access-date=19 July 2021 |archive-date=28 February 2022 |archive-url=https://web.archive.org/web/20220228013854/https://www.aljazeera.com/news/2021/7/18/algeria-recalls-envoy-to-morocco-in-row-over-western-sahara |url-status=live }}</ref>

Tuareg people in Mali rebelled several times during the 20th century before finally forcing the Malian armed forces to withdraw below the line demarcating Azawad from southern Mali during the 2012 rebellion.<ref>{{cite news |title=Mali Tuareg rebels declare independence in the north |url=https://www.bbc.com/news/world-africa-17635437 |publisher=BBC News |date=6 April 2012 |access-date=19 July 2021 |archive-date=21 January 2022 |archive-url=https://web.archive.org/web/20220121083408/https://www.bbc.com/news/world-africa-17635437 |url-status=live }}</ref> Islamist rebels in the Sahara calling themselves al-Qaeda in the Islamic Maghreb have stepped up their violence in recent years.<ref>{{cite news |title=Al-Qaeda in North Africa appoints new leader to replace Droukdel |url=https://www.france24.com/en/africa/20201122-al-qaeda-in-north-africa-appoints-new-leader-to-replace-droukdel |work=France 24 |date=22 November 2020 |access-date=19 July 2021 |archive-date=7 November 2021 |archive-url=https://web.archive.org/web/20211107084919/https://www.france24.com/en/africa/20201122-al-qaeda-in-north-africa-appoints-new-leader-to-replace-droukdel |url-status=live }}</ref>

In the post–World War II era, several mines and communities have developed to use the desert's natural resources. These include large deposits of oil and natural gas in Algeria and Libya, and large deposits of phosphates in Morocco and Western Sahara.<ref>{{cite news |title=The Desert Rock That Feeds the World |url=https://www.theatlantic.com/science/archive/2016/11/the-desert-rock-that-feeds-the-world/508853/ |work=The Atlantic |date=29 November 2016 |access-date=19 July 2021 |archive-date=25 February 2022 |archive-url=https://web.archive.org/web/20220225060703/https://www.theatlantic.com/science/archive/2016/11/the-desert-rock-that-feeds-the-world/508853/ |url-status=live }}</ref> Libya's Great Man-Made River is the world's largest irrigation project.<ref>{{cite news |title=Libya's Qaddafi taps 'fossil water' to irrigate desert farms |url=https://www.csmonitor.com/World/Africa/2010/0823/Libya-s-Qaddafi-taps-fossil-water-to-irrigate-desert-farms/%28page%29/2 |work=CSMonitor.com |date=23 August 2010 |access-date=19 July 2021 |archive-date=19 January 2022 |archive-url=https://web.archive.org/web/20220119120123/https://www.csmonitor.com/World/Africa/2010/0823/Libya-s-Qaddafi-taps-fossil-water-to-irrigate-desert-farms/(page)/2 |url-status=live }}</ref> The project uses a pipeline system that pumps fossil water from the Nubian Sandstone Aquifer System to cities in the populous Libyan northern Mediterranean coast including Tripoli and Benghazi.<ref>{{cite web|url=https://en.qantara.de/content/libyas-great-man-made-river-irrigation-project-the-eighth-wonder-of-the-world|title=The Eighth Wonder of the World?|author=Moutaz Ali|year=2017|website=Quantara.de|access-date=19 July 2021|archive-date=19 December 2021|archive-url=https://web.archive.org/web/20211219152751/https://en.qantara.de/content/libyas-great-man-made-river-irrigation-project-the-eighth-wonder-of-the-world|url-status=live}}</ref>

A number of Trans-African highways have been proposed across the Sahara, including the Cairo–Dakar Highway along the Atlantic coast, the Trans-Sahara Highway from Algiers on the Mediterranean to Kano in Nigeria, the Tripoli – Cape Town Highway from Tripoli in Libya to N'Djamena in Chad, and the Cairo – Cape Town Highway which follows the Nile. Each of these highways is partially complete, with significant gaps and unpaved sections.

==Peoples and languages== {{Further|Saharan languages|Saharan rock art|Rock art#Sahara}} [[File:Niger, Toubou people at Koulélé (11).jpg|thumb|Toubou people from central Sahara speak Saharan languages]] The people of the Sahara are of various origins. Among them the Amazigh including the Tuareg, various Arabized Amaziɣ groups such as the Hassaniya-speaking Sahrawis, whose populations include the Znaga, a tribe whose name is a remnant of the pre-historic Zenaga language. Other major groups of people include the: Toubou, Nubians, Zaghawa, Kanuri, Hausa, Songhai, Beja, and Fula/Fulani ({{langx|fr|Peul}}; {{langx|ff|Fulɓe}}). The archaeological evidence from the Holocene period has shown that Nilo-Saharan speaking groups had populated the central and southern Sahara before the influx of Berber and Arabic speakers, around 1500 years ago, who now largely populate the Sahara in the modern era.<ref>{{cite journal |last1=Drake |first1=Nick A. |last2=Blench |first2=Roger M. |last3=Armitage |first3=Simon J. |last4=Bristow |first4=Charlie S. |last5=White |first5=Kevin H. |title=Ancient watercourses and biogeography of the Sahara explain the peopling of the desert |journal=Proceedings of the National Academy of Sciences of the United States of America |date=11 January 2011 |volume=108 |issue=2 |pages=458–462 |doi=10.1073/pnas.1012231108 |pmid=21187416 |pmc=3021035 |bibcode=2011PNAS..108..458D |doi-access=free }}</ref> The Haratins, are believed to largely descend from native ancient black populations that inhabited the Sahara.<ref name=":1">{{cite journal |last1=Keita |first1=S. O. Y. |date=1993 |title=Studies and Comments on Ancient Egyptian Biological Relationships |journal=History in Africa |volume=20 |pages=140 |doi=10.2307/3171969 |jstor=3171969 |quote=Paoli (1972) found dynastic mummies to have ABO frequencies most like those of the northern Haratin, a group believed to be largely descended from the ancient Saharans.}}</ref><ref name=":2">{{Cite book |last=Batran |first=Aziz Abdallah |chapter-url=https://books.google.com/books?id=HVGRAgAAQBAJ&dq=haratin%20black%20populations%20sahara&pg=PA4 |title=Slaves and Slavery in Africa: Volume Two: The Servile Estate |date=1985 |publisher=Routledge |isbn=978-1-135-78016-6 |editor-last=Willis |editor-first=John Ralph |language=en |chapter=The ‘Ulama’ of Fas, Mulay Isma‘il and the Issue of the Haratin of Fas |quote=Although the origin of the Haratin is shrouded in mystery, it is generally believed that they were indigenous to the north Saharan oases, hybrids between an ancient black population and Berbers, and most of them had dark skin and negroid features. The Haratin did not constitute a tribe, rather they were groups of families scattered amongst North African and Saharan Arab and Berber tribes. Though the Haratin were free men, they were generally considered to be of inferior social status, between slaves and free men (hur thani). Most of the Haratin were farmworkers and not landowners, receiving a fifth (Khammas) of the harvest from Arab and Berber landlords, for their work. In general, the Haratin were a class of people "who were in many ways like slaves: i.e. non-tribal, economically vulnerable, socially debased and pheno-typically distinct."}}</ref> [[File:Detailed Afroasiatic map.svg|thumb|left|Geographical distribution of Afroasiatic languages and varieties of Arabic]]

[[File:Haratin women of Telouet, Southern Morocco, in an ahouach performance.jpg|thumbnail|Haratin women of Telouet, Southern Morocco, in a houach performance]]

Arabic dialects are the most widely spoken languages in the Sahara. Arabic, Berber and its variants now regrouped under the term Amazigh (which includes the Guanche language spoken by the original Berber inhabitants of the Canary Islands) and Beja languages are part of the Afro-Asiatic or Hamito-Semitic family.{{citation needed|date=February 2013}} Unlike neighboring West Africa and the central governments of the states that comprise the Sahara, the French language bears little relevance to inter-personal discourse and commerce within the region, its people retaining staunch ethnic and political affiliations with Tuareg and Berber leaders and culture.<ref>Jane E. Goodman (2010) [2005]). ''Berber Culture on the World Stage: From Village to Video''. Indiana University Press, {{ISBN|978-0-253-21784-4}} pp. 49–68</ref> The legacy of the French colonial era administration is primarily manifested in the territorial reorganization enacted by the Third and Fourth republics, which engendered artificial political divisions within a hitherto isolated and porous region.<ref>Ralph A. Austen. ''Trans-Saharan Africa in World History''. Oxford University Press, 2010. {{ISBN|0-19-979883-4}}</ref> Diplomacy with local clients was conducted primarily in Arabic, which was the traditional language of bureaucratic affairs. Mediation of disputes and inter-agency communication was served by interpreters contracted by the French government, who, according to Keenan, "documented a space of intercultural mediation," contributing much to preserving the indigenous cultural identities in the region.<ref>Jeremy Keenan, ed. (2013). ''The Sahara: Past, Present and Future''. Routledge, {{ISBN|1-317-97001-2}}</ref>

==See also==

* {{annotated link|African humid period}} * {{annotated link|Arid Lands Information Network}} * {{annotated link|List of deserts}} * {{annotated link|List of deserts by area}} * {{annotated link|List of Saharan explorers}} * {{annotated link|Sahara Conservation Fund}} * {{annotated link|Sahara Sea}} * {{annotated link|Trans-Saharan slave trade}}

==References== {{reflist}}

==Bibliography== * {{Cite book |last1=Brett |first1=Michael |last2=Fentress |first2=Elizabeth W. B. |title=The Berbers |date=1997 |publisher=Blackwell |isbn=978-0-631-20767-2 |series=The peoples of Africa |location=Malden}} * {{Cite book |last=Bulliet |first=Richard W. |url=https://archive.org/details/camelwheel0000bull |title=The Camel and the Wheel |date=1975 |publisher=Harvard University Press |isbn=978-0-674-09130-6 |location=Cambridge, Mass |url-access=registration}} Republished with a new preface Columbia University Press, 1990. * {{Cite book |last=Gearon |first=Eamonn |url=https://books.google.com/books?id=enp7YqIsci8C |title=The Sahara: a cultural history |date=2011 |publisher=Oxford University Press |isbn=978-0-19-986195-8 |series=Landscapes of the imagination |location=Oxford}} * {{Cite book |last=Julien |first=Charles-André |author-link=Charles-André Julien |url=https://archive.org/details/historyofnorthaf0000juli/ |title=History of North Africa: Tunisia, Algeria, Morocco, from the Arab Conquest to 1830 |editor-last=Le Tourneau |editor-first=Roger |editor-last2=Stewart |editor-first2=C. C. |translator-last=Petrie |translator-first=John |date=1970 |publisher=Routledge & K. Paul |isbn=978-0-7100-6614-5 |location=London}} * {{Cite book |last=Kennedy |first=Hugh |url=https://archive.org/details/muslimspainportu00unse |title=Muslim Spain and Portugal: A Political History of al-Andalus |date=1996 |publisher=Longman |isbn=978-0-582-49515-9 |location=Harlow}} * {{Cite book |last=Laroui |first=Abdallah |author-link=Abdallah Laroui |url=https://archive.org/details/TheHistoryOfTheMaghribAnInterpretiveEssay/ |title=The History of the Maghrib: An Interpretive Essay |date=1977 |publisher=Princeton University Press |isbn=978-0-691-03109-5 |location=Princeton}} * {{cite book |author=Scott |first=Chris |title=Sahara Overland, 2nd A Route and Planning Guide |date=2005 |publisher=Trailblazer Guides |isbn=9781873756768 |location=Hindhead, Surrey, UK}} * {{cite journal|last=Wade|first=Lizzie|url=https://www.science.org/content/article/drones-and-satellites-spot-lost-civilizations-unlikely-places |title=Drones and Satellites Spot Lost Civilizations in Unlikely Places|journal=Science |date=2015|doi=10.1126/science.aaa7864|doi-access=free|url-access=subscription}}

==External links== {{Sister project links|auto=1|wikt=1}} * [http://www.saudiaramcoworld.com/issue/200701/seas.beneath.the.sands.htm About Sahara subsurface hydrology and planned usage of the aquifers] {{Webarchive|url=https://web.archive.org/web/20140805112417/http://www.saudiaramcoworld.com/issue/200701/seas.beneath.the.sands.htm |date=5 August 2014 }} * {{Cite EB1911|wstitle= Sahara | volume= 23 |last1= Heawood |first1= Edward |author1-link=Edward Heawood |last2= Cana |first2= Frank Richardson |author2-link= || pages = 1004–1008 |short= 1}}

Category:Sahara Category:Articles containing video clips Category:Deserts and xeric shrublands Category:Deserts of Africa Category:Geography of North Africa Category:Geography of the Arab world Category:Palearctic realm Category:Physiographic provinces