Neolithic Subpluvial - wikipedia Neolithic Subpluvial Part of a series on the History of Algeria Prehistory Aterian Culture ( 80,000 BC ) Iberomaurusian Culture ( 20,000 BC ) Capsian culture ( 10,000 BC ) Rock art in Oran, Djelfa, Tassili and Ahaggar Green Sahara Roknia Madghacen Jedars Related : Archeology of Algeria Antiquity Getulia ( ~ 500 BC -- 40 AD ) Numidia ( 202 -- 46 BC ) Punic Wars ( 264 -- 146 BC ) Jugurthine War ( 111 -- 106 BC ) Roman Mauretania and Africa ( 146 BC -- 590 AD ) Vandalic War ( 533 -- 534 AD ) Prefecture of Africa ( 534 -- 585 AD ) Exarchate of Africa ( 585 -- 698 AD ) Early African Church Partenia Fossatum Africae Gemellae Middle Ages Arab conquest ( 647 -- 709 AD ) Umayyads ( 703 -- 744 AD ) Ifranids ( 742 -- 1066 AD ) Muhallabids ( 771 -- 793 AD ) Rustamids ( 776 -- 909 AD ) Idrisids ( 789 -- 828 AD ) Aghlabids ( 800 -- 909 AD ) Fatimids ( 909 -- 1171 AD ) Maghrawas ( 970 -- 1068 AD ) Zirids ( 973 -- 1152 AD ) Hammadids ( 1014 -- 1152 AD ) Almoravids ( 1040 -- 1147 AD ) Almohads ( 1121 -- 1269 AD ) Marinids ( 1215 -- 1465 AD ) Hafsids ( 1229 -- 1574 AD ) Ziyyanids ( 1235 -- 1556 AD ) Modern times Ottoman Algeria ( 16th - 19th centuries ) Regency of Algiers Ottoman governors Emirate of Ait Abbas Emirate of Kuku Barbary pirates Barbary Slave Trade First Barbary War Second Barbary War French Algeria ( 19th - 20th centuries ) French conquest French governors Resistance Pacification Emir Abdelkader Fatma N'Soumer Mokrani Revolt Cheikh Bouamama Nationalism RCUA FLN GPRA Algerian War 1958 putsch 1961 putsch Évian Accords Independence referendum Pied - Noir Harkis Oujda Group Contemporary era 1960s -- 80s Arab nationalism 1965 putsch Berber Spring 1988 Riots 1990s Algerian Civil War ( Timeline ) FIS GIA List of massacres High Council of State Civil Concord 2000s to present Peace Charter AQIM Arab Spring Related topics Outline of Algeria Military history of Algeria ( List of wars involving Algeria ) Postal history of Algeria ( List of people on stamps of Algeria ) History of North Africa Algeria portal Part of a series on the History of Niger Bura culture Songhai Empire Mali Empire Dendi Kingdom Gao Empire Kanem Bornu Bornu Empire French Colonization Independence Hamani Diori 1974 coup d'etat First Tuareg Rebellion Second Tuareg Rebellion 2009 -- 10 constitutional crisis See also Years in Niger Niger portal Part of a series on the History of Chad Kanem Empire Ouaddai Empire French colonial period Tombalbaye government Civil War ( 1965 -- 79 ) Malloum government Transitional Government Habré Era Conflict with Libya Toyota War Déby Era Civil War ( 2005 -- 10 ) Chad portal The Neolithic Subpluvial, or the Holocene Wet Phase, was an extended period ( from about 7500 -- 7000 BCE to about 3500 -- 3000 BCE ) of wet and rainy conditions in the climate history of northern Africa. It was both preceded and followed by much drier periods. The Neolithic Subpluvial was the most recent of a number of periods of `` Wet Sahara '' or `` Green Sahara '', during which the Sahara region was much moister and supported a richer biota and human population than the present - day desert. Contents 1 Date ranges 2 Geography and hydrography 3 Ecology 4 Cultures 5 See also 6 References 7 Further reading 8 External links Date ranges The Neolithic Subpluvial began during the 7th millennium BCE and was strong for about 2,000 years ; it waned over time and ended after the 5.9 kiloyear event ( 3900 BCE ). Then the drier conditions that prevailed prior to the Neolithic Subpluvial returned ; desertification advanced, and the Sahara Desert formed ( or re-formed ). Arid conditions have continued through to the present day. Geography and hydrography During the Neolithic Subpluvial, large areas of North, Central, and East Africa had hydrographic profiles significantly different from later norms. Existing lakes had surfaces tens of meters higher than today, sometimes with alternative drainages : Lake Turkana, in present - day Kenya, drained into the Nile River basin. Lake Chad reached a maximum extent of some 400,000 square kilometers in surface area, larger than the modern Caspian Sea, with a surface level about 30 meters ( 100 feet ) higher than its twentieth - century average. Some shallower lakes and river systems existed in the subpluvial era that later disappeared entirely, and are detectable today only via radar and satellite imagery. The event is argued to have ended quickly in some places and more slowly in others. Local feedbacks between vegetation and the atmosphere may explain the variability in the records But, the agents of initial devegetation are unknown since they seem to occur rapidly in some areas, which is out of phase with changing orbital precession. The introduction of domesticated animals correlates in many places to a rapid change from grassland to scrubland vegetation, and it is hypothesized that Neolithic humans may have potentially played a role in stripping vegetation from the landscape, which induced cascading effects to the ecosystem and climate. Ecology North Africa enjoyed a fertile climate during the subpluvial era ; what is now the Sahara supported a savanna type of ecosystem, with elephant, giraffe, and other grassland and woodland animals now typical of the Sahel region south of the desert, along with some now extinct megafauna such as Sivatherium and Pelorovis. Historian and Africanist Roland Oliver has described the scene as follows : ( In ) the highlands of the central Sahara Desert beyond the Libyan Desert,... in the great massifs of the Tibesti and the Hoggar, the mountaintops, today bare rock, were covered at this period with forests of oak and walnut, lime, alder and elm. The lower slopes, together with those of the supporting bastions -- the Tassili and the Acacus to the north, Ennedi and Air to the south -- carried olive, juniper and Aleppo pine. In the valleys, perennially flowing rivers teemed with fish and were bordered by seed - bearing grasslands. Cultures Main article : Prehistoric North Africa Clement and fertile conditions during the Neolithic Subpluvial supported increased human settlement of the Nile Valley in Egypt, as well as neolithic societies in Sudan and throughout the present - day Sahara. Cultures producing rock art ( notably that at Tassili n'Ajjer in southeastern Algeria ) flourished during this period. The practical consequences of these changes took the form of increased abundance of fish, waterfowl, freshwater mollusks, rodents, hippopotamus and crocodiles. The riches of this increased aquatic biomass were exploited by humans with rafts, boats, weirs, traps, harpoons, nets, hooks, lines and sinkers. This `` riparian '' ( river ) way of life supported much larger communities than could that of typical hunting bands. These changes, along with the local development of pottery ( whereby liquids could be both stored and heated ) resulted in a `` culinary revolution '' consisting of soup, fish stew and porridge. The last mentioned implies the cooking of gathered cereals. The classic account of the riparian lifestyle of this period comes from investigations in Sudan during World War II by British archeologist Anthony Arkell. Arkell 's report described a Late Stone Age settlement on a sandbank of the Blue Nile which was then about 12 feet ( 3.7 m ) higher than its present flood stage. The countryside was clearly savanna, not the present - day desert, as evidenced by the bones of the most common species found in the middens -- antelope, which require large expanses of seed - bearing grasses. These people probably lived mainly on fish, however, and Arkell concluded, based on the totality of the evidence, that rainfall at the time was at least three times that of today. The physical characteristics derived from skeletal remains suggested that these people were related to modern Nilotic peoples, such as the Nuer and Dinka. Subsequent radiocarbon dating firmly established Arkell 's site to between 7000 and 5000 BCE. Based on common patterns at his site and at French - excavated sites already reported from Chad, Mali and Niger ( e.g., bone harpoons and a characteristic `` wavy line '' pottery ), Arkell inferred `` a common fishing and hunting culture spread by negroid people right across Africa at about the latitude of Khartoum at a time when the climate was so different that it was not desert. '' The originators of the wavy line pottery are as yet unidentified. In the 1960s, the archeologist Gabriel Camps investigated the remains of a hunting and fishing community dating from about 6700 BCE in southern Algeria. These pottery - making people ( the `` wavy line '' motif again ) were black African rather than Mediterranean in origin and ( according to Camps ) evidenced definite signs of deliberate cultivation of grain crops as opposed to simply the gathering of wild grains. Later studies at the site have shown the culture to be hunter - gatherers and not agriculturalists, as all the grains were morphologically wild, and the society was not sedentary. Human remains were found by archaeologists in 2000 at a site known as Gobero in the Ténéré Desert of northeastern Niger. The Gobero finds represent a uniquely preserved record of human habitation and burials from what is now called the Kiffian ( 7,700 -- 6,200 BCE ) and the Tenerian ( 5,200 -- 2,500 BCE ) cultures. Dotted wavy line pottery and fishing cultures have also been located in the Lake Turkana region in poorly dated contexts. By 3,000 BCE, it does not appear that the Turkana Basin was populated with harpoon and dotted wavy line pottery users, but fishing remained an important part of peoples ' diets into the late Holocene. See also Abbassia Pluvial Ancient Libya Germa Mechta - Afalou Mousterian Pluvial North African climate cycles Older Peron Piora Oscillation Pluvial Rock art of the Djelfa region Sahara pump theory Sahel Sahel drought References Jump up ^ Sources differ on specific date ranges, which necessarily varied over such a wide geographic expanse. One ( Bard, Kathryn A. ( 1999 ), ed. Encyclopedia of the Archaeology of Ancient Egypt. London, Routledge, pg 863 ) gives `` 9000 -- 5000 BP, '' or 7000 -- 3000 BCE, for the duration of the subpluvial. Another ( Wilkinson, Toby A.H. ( 1999 ), Early Dynastic Egypt. London, Routledge, pg 372 ) places the end of the subpluvial c. 3300 BCE. Jump up ^ Bloszies, C. ; Forman, S.L. ; Wright, D.K. ( 2015 - 09 - 01 ). `` Water level history for Lake Turkana, Kenya in the past 15,000 years and a variable transition from the African Humid Period to Holocene aridity ''. Global and Planetary Change. 132 : 64 -- 76. doi : 10.1016 / j. gloplacha. 2015.06. 006. Jump up ^ deMenocal, Peter ; Ortiz, Joseph ; Guilderson, Tom ; Adkins, Jess ; Sarnthein, Michael ; Baker, Linda ; Yarusinsky, Martha ( 2000 - 01 - 01 ). `` Abrupt onset and termination of the African Humid Period : : rapid climate responses to gradual insolation forcing ''. Quaternary Science Reviews. 19 ( 1 -- 5 ) : 347 -- 361. doi : 10.1016 / S0277 - 3791 ( 99 ) 00081 - 5. Jump up ^ Salzmann, Ulrich. `` Late Quaternary Climate and Vegetation of the Sudanian Zone of Northeast Nigeria - ScienceDirect ''. Quaternary Research. 58 : 73 -- 83. doi : 10.1006 / qres. 2002.2356. Retrieved 2017 - 03 - 10. Jump up ^ Lézine, Anne - Marie ; Hély, Christelle ; Grenier, Christophe ; Braconnot, Pascale ; Krinner, Gerhard ( 2011 - 10 - 01 ). `` Sahara and Sahel vulnerability to climate changes, lessons from Holocene hydrological data ''. Quaternary Science Reviews. 30 ( 21 -- 22 ) : 3001 -- 3012. doi : 10.1016 / j. quascirev. 2011.07. 006. Jump up ^ Kutzbach, J.E. ( 1996 ). `` Potential role of vegetation feedback in the climate sensitivity of high - latitude regions : A case study at 6000 years B.P. '' Global biogeochemical cycles. 10 ( 4 ). ISSN 0886 - 6236. Jump up ^ Wright, David K. ( 26 January 2017 ). `` Humans as Agents in the Termination of the African Humid Period ''. Frontiers in Earth Science. 5. doi : 10.3389 / feart. 2017.00004. ISSN 2296 - 6463. Jump up ^ Oliver, Roland ( 1999 ), The African Experience : From Olduvai Gorge to the 21st Century ( Series : History of Civilization ), London : Phoenix Press, revised edition, pg 39. Jump up ^ Oliver, pg 37. Jump up ^ Sutton, John E.G. ( 1974 ). `` The Aquatic Civilization of Middle Africa ''. Journal of African History. 15 : 527 -- 546. doi : 10.1017 / s0021853700013864. Jump up ^ Arkell, A.J. ( 1949 ), Early Khartoum, Oxford University Press. Jump up ^ Camps, Gabriel ( 1974 ), Les civilisation prehistoriques de l'Afrique du Nord et du Sahara, Paris, pp 22 and 225 -- 226. The site is Amekni near Tamanrasset. Jump up ^ `` Stone Age Graveyard Reveals Lifestyles Of A ' Green Sahara ' ''. Science Daily. 15 August 2008. Retrieved 15 August 2008. Jump up ^ Gwin P. ( September 2008 ), Lost tribes of the green sahara, National Geographic Magazine ^ Jump up to : Wright, David K. ; Forman, Steven L. ; Kiura, Purity ; Bloszies, Christopher ; Beyin, Amanuel ( 2015 - 06 - 01 ). `` Lakeside View : Sociocultural Responses to Changing Water Levels of Lake Turkana, Kenya ''. African Archaeological Review. 32 ( 2 ) : 335 -- 367. doi : 10.1007 / s10437 - 015 - 9185 - 8. ISSN 0263 - 0338. Further reading Burroughs, William J., ed. Climate : Into the 21st Century. Cambridge, Cambridge University Press, 2003 Howell, Francis Clark, and François Bourlière. African Ecology and Human Evolution. London, Routledge, 2004 ( reprint of the 1964 edition ) Eamonn Gearon. `` The Sahara : A Cultural History. '' Signal Books, UK, 2011. Oxford University Press, USA. 2011. Garcea, E.A.A. ( ed. ) 2013. Gobero : The No - Return Frontier. Archaeology and Landscape at the Saharo - Sahelian Borderland. Frankfurt, Africa Magna Verlag. External links Orbit : Earth 's Extraordinary Journey Retrieved from `` https://en.wikipedia.org/w/index.php?title=Neolithic_Subpluvial&oldid=835284238 '' Categories : Climate Climatology Climate history History of the Sahara Prehistoric Africa Hidden categories : Use dmy dates from November 2012 Pages using div col with deprecated parameters Talk Contents About Wikipedia Deutsch فارسی 한국어 Italiano Nederlands Русский Suomi Українська Edit links This page was last edited on 7 April 2018, at 18 : 45. Text is available under the Creative Commons Attribution - ShareAlike License ; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia ® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization. About Wikipedia

Question: when was the last time the sahara was green
Answer: 3900 BCE