Human

== Habitat and population ==
{{Further|Human geography| Demography}}
{{Infobox
| image            = [[File:Global population cartogram.png|thumb|upright=2.05
| Mosaic [[cartogram]] showing the distribution of the global population based on 2018 UN data. Each of the 15,266 pixels represents the home country of 500,000 people – cartogram by [[Max Roser]] for [[Our World in Data]]]]

| image2            = [[File:Population Density, v4.11, 2020 (48009093621).jpg|thumb|upright=2.05
| [[Choropleth]] showing [[Population density]] (people per square kilometer) estimates by 30 arc-second grid in 2020]]
| title            = Population statistics{{#tag:ref|The world population and population density statistics are updated automatically from a template that uses the CIA World Factbook and United Nations World Population Prospects.<ref>{{cite web |url=https://www.cia.gov/the-world-factbook/countries/world |title=World |work=[[The World Factbook]] |publisher=[[CIA]] |date=17 May 2016 |access-date=2 October 2016 |archive-date=26 January 2021 |archive-url=https://web.archive.org/web/20210126032610/https://www.cia.gov/the-world-factbook/countries/world/ |url-status=live }}</ref><ref>{{cite web |url=https://esa.un.org/unpd/wpp/Publications/Files/WPP2017_KeyFindings.pdf |publisher=United Nations, Department of Economic and Social Affairs, Population Division |date=2017 |title=World Population Prospects: The 2017 Revision |page=2&17 |access-date=30 July 2022 |archive-date=26 June 2019 |archive-url=https://web.archive.org/web/20190626225001/https://esa.un.org/unpd/wpp/Publications/Files/WPP2017_KeyFindings.pdf |url-status=live }}</ref>|group=n}}
| label1           = [[World population]]
| data1            = {{#expr: {{data world|poptoday}} / 1e9 round 1}}&nbsp;billion
| label2           = [[Population density#Human population density|Population density]]
| data2            = {{Pop density|{{data world|poptoday}}|{{data world|pst2|total area}}|km2|sqmi|prec=0}} by total area<br />{{Pop density|{{data world|poptoday}}|{{data world|pst2|land area}}|km2|sqmi|prec=0}} by land area
| label3           = [[List of largest cities|Largest cities]]{{#tag:ref|Cities with over 10 million inhabitants as of 2018.<ref>{{cite news|title=The World's Cities in 2018|url=https://www.un.org/en/events/citiesday/assets/pdf/the_worlds_cities_in_2018_data_booklet.pdf|access-date=|newspaper=[[United Nations]]|archive-date=1 November 2018|archive-url=https://web.archive.org/web/20181101135338/http://www.un.org/en/development/desa/population/publications/pdf/urbanization/the_worlds_cities_in_2018_data_booklet.pdf|url-status=live}}</ref>|group=n}}
| data3            = [[Tokyo]], [[Delhi]], [[Shanghai]], [[São Paulo]], [[Mexico City]], [[Cairo]], [[Mumbai]], [[Beijing]], [[Dhaka]], [[Osaka]], [[New York City|New York]]-[[Newark, New Jersey|Newark]], [[Karachi]], [[Buenos Aires]], [[Chongqing]], [[Istanbul]], [[Kolkata]], [[Manila]], [[Lagos]], [[Rio de Janeiro]], [[Tianjin]], [[Kinshasa]], [[Guangzhou]], [[Los Angeles]]-[[Long Beach]]-[[Santa Ana, California|Santa Ana]], [[Moscow]], [[Shenzhen]], [[Lahore]], [[Bangalore]], [[Paris]], [[Jakarta]], [[Chennai]], [[Lima]], [[Bogotá|Bogota]], [[Bangkok]], [[London]]
}}

Early human settlements were dependent on proximity to [[water resources|water]] and{{snd}}depending on the lifestyle{{snd}}other [[natural resource]]s used for [[subsistence]], such as populations of animal prey for [[hunting]] and [[arable land]] for growing crops and grazing livestock.<ref>{{cite book|vauthors=Rector RK|url=https://www.worldcat.org/oclc/953735302|title=The Early River Valley Civilizations|date=2016|isbn=978-1-4994-6329-3|edition=First|location=New York|page=10|oclc=953735302|access-date=30 July 2022|archive-date=30 July 2022|archive-url=https://web.archive.org/web/20220730032849/https://www.worldcat.org/title/early-river-valley-civilizations/oclc/953735302|url-status=live |publisher=Rosen Publishing }}</ref> Modern humans, however, have a great capacity for altering their [[habitat (ecology)|habitats]] by means of technology, [[irrigation]], [[urban planning]], construction, [[deforestation]] and [[desertification]].<ref>{{cite web |url=https://www.westerville.k12.oh.us/userfiles/4188/Classes/7526/humanforcesthatchangeenvironment.pdf?id=448117 |title=How People Modify the Environment |author=<!--Not stated--> |publisher=[[Westerville City School District]] |access-date=13 March 2019 |archive-date=25 February 2021 |archive-url=https://web.archive.org/web/20210225132108/http://www.westerville.k12.oh.us/userfiles/4188/Classes/7526/humanforcesthatchangeenvironment.pdf?id=448117 |url-status=live }}</ref> [[Human settlements]] continue to be [[vulnerability|vulnerable]] to [[natural disasters]], especially those placed in hazardous locations and with low quality of construction.<ref>{{cite web |url=https://siteresources.worldbank.org/INTLACREGTOPHAZMAN/Resources/EN_Breve_Oct03_32_Nat_Dis_EN.pdf |title=Natural disasters and the urban poor |publisher=[[World Bank]] |date=October 2003 |url-status=live |archive-url=https://web.archive.org/web/20170809063303/https://siteresources.worldbank.org/INTLACREGTOPHAZMAN/Resources/EN_Breve_Oct03_32_Nat_Dis_EN.pdf |archive-date=9 August 2017 }}</ref> Grouping and deliberate habitat alteration is often done with the goals of providing protection, accumulating comforts or material wealth, expanding the available food, improving [[aesthetics]], increasing knowledge or enhancing the exchange of resources.<ref>{{cite book|vauthors=Habitat UN|url=https://www.worldcat.org/oclc/889953315|title=The state of the world's cities 2012 / prosperity of cities.|date=2013|publisher=Routledge|isbn=978-1-135-01559-6|location=[London]|pages=x|oclc=889953315|access-date=30 July 2022|archive-date=30 July 2022|archive-url=https://web.archive.org/web/20220730032849/https://www.worldcat.org/title/state-of-the-worlds-cities-2012-prosperity-of-cities/oclc/889953315|url-status=live}}</ref>

Humans are one of the most [[Adaptation|adaptable]] species, despite having a low or narrow tolerance for many of the earth's extreme environments.<ref name="Piantadosi-2003">{{cite book|vauthors=Piantadosi CA|url=https://www.worldcat.org/oclc/70215878|title=The biology of human survival : life and death in extreme environments|date=2003|publisher=Oxford University Press|isbn=978-0-19-974807-5|location=Oxford|pages=2–3|oclc=70215878|access-date=30 July 2022|archive-date=30 July 2022|archive-url=https://web.archive.org/web/20220730032850/https://www.worldcat.org/title/biology-of-human-survival-life-and-death-in-extreme-environments/oclc/70215878|url-status=live}}</ref> Currently the species is present in all eight [[biogeographical realms]], although their presence in the [[Antarctic realm]] is very limited to [[Research stations in Antarctica|research stations]] and annually there is a population decline in the winter months of this realm. Humans established their nation-states in the other seven realms, such as for example [[South Africa]], [[India]], [[Russia]], [[Australia]], [[Fiji]], [[United States]] and [[Brazil]] (each located in a different biogeographical realm).

By using advanced tools and [[clothing]], humans have been able to extend their tolerance to a wide variety of temperatures, [[humidity|humidities]], and altitudes.<ref name="Piantadosi-2003" /><ref>{{cite journal |last1=Toups |first1=M.A. |last2=Kitchen |first2=A. |last3=Light |first3=J.E. |last4=Reed |first4=D.L. |year=2011 |title=Origin of clothing lice indicates early clothing use by anatomically modern humans in Africa |journal=Molecular Biology and Evolution |volume=28 |issue=1 |pages=29–32 |doi=10.1093/molbev/msq234 |pmc=3002236 |pmid=20823373}}</ref> As a result, humans are a [[Cosmopolitan distribution|cosmopolitan]] species found in almost all regions of the world, including [[tropical rainforest]], [[desert|arid desert]], extremely cold [[arctic region]]s, and heavily polluted cities; in comparison, most other species are confined to a few geographical areas by their limited adaptability.<ref name="adapt1">{{cite web |vauthors=O'Neil D |title=Human Biological Adaptability; Overview |url=https://anthro.palomar.edu/adapt/adapt_1.htm |url-status=dead |archive-url=https://web.archive.org/web/20130306124405/https://anthro.palomar.edu/adapt/adapt_1.htm |archive-date=6 March 2013 |access-date=6 January 2013 |publisher=Palomar College}}</ref> The [[human population]] is not, however, uniformly distributed on the [[Earth]]'s surface, because the population density varies from one region to another, and large stretches of surface are almost completely uninhabited, like [[Antarctica]] and vast swathes of the ocean.<ref name="Piantadosi-2003" /><ref>{{cite web |url=https://www.bbc.co.uk/schools/gcsebitesize/geography/population/population_distribution_rev1.shtml |publisher=BBC |title=Population distribution and density |url-status=dead |archive-url=https://web.archive.org/web/20170623234027/https://www.bbc.co.uk/schools/gcsebitesize/geography/population/population_distribution_rev1.shtml |archive-date=23 June 2017 |access-date=26 June 2017 }}</ref> Most humans (61%) live in Asia; the remainder live in the Americas (14%), Africa (14%), Europe (11%), and Oceania (0.5%).<ref>{{cite journal |vauthors=Bunn SE, Arthington AH |title=Basic principles and ecological consequences of altered flow regimes for aquatic biodiversity |journal=[[Environmental Management (journal)|Environmental Management]] |volume=30 |issue=4 |pages=492–507 |date=October 2002 |pmid=12481916 |doi=10.1007/s00267-002-2737-0 |hdl-access=free |s2cid=25834286 |hdl=10072/6758}}</ref>

Within the last century, humans have explored challenging environments such as Antarctica, the [[deep sea]], and [[outer space]].<ref name="Heim-1991">{{cite journal |vauthors=Heim BE |year=1990–1991 |title=Exploring the Last Frontiers for Mineral Resources: A Comparison of International Law Regarding the Deep Seabed, Outer Space, and Antarctica |url=https://heinonline.org/HOL/Page?handle=hein.journals/vantl23&id=831&div=&collection= |journal=[[Vanderbilt Journal of Transnational Law]] |volume=23 |page=819 |access-date=30 July 2022 |archive-date=23 June 2021 |archive-url=https://web.archive.org/web/20210623152719/https://heinonline.org/HOL/Page?handle=hein.journals%2Fvantl23&id=831&div=&collection= |url-status=live}}</ref> Human habitation within these hostile environments is restrictive and expensive, typically limited in duration, and restricted to [[Science|scientific]], [[military]], or [[Industry (economics)|industrial]] expeditions.<ref name="Heim-1991" /> Humans have briefly visited the [[exploration of the Moon|Moon]] and made their presence felt on other [[Astronomical object|celestial bodies]] through human-made [[robotic spacecraft]].<ref>{{cite web |url=https://www.jpl.nasa.gov/missions/mars-science-laboratory-curiosity-rover-msl/ |title=Mission to Mars: Mars Science Laboratory Curiosity Rover |publisher=Jet Propulsion Laboratory |access-date=26 August 2015 |url-status=live |archive-url=https://web.archive.org/web/20150818014850/https://www.jpl.nasa.gov/missions/mars-science-laboratory-curiosity-rover-msl |archive-date=18 August 2015 }}</ref><ref>{{cite web |url=https://www.esa.int/Our_Activities/Space_Science/Rosetta/Touchdown!_Rosetta_s_Philae_probe_lands_on_comet |title=Touchdown! Rosetta's Philae probe lands on comet |date=12 November 2014 |publisher=European Space Agency |access-date=26 August 2015 |url-status=live |archive-url=https://web.archive.org/web/20150822055902/https://www.esa.int/Our_Activities/Space_Science/Rosetta/Touchdown!_Rosetta_s_Philae_probe_lands_on_comet |archive-date=22 August 2015 }}</ref><ref>{{cite web |url=https://science.nasa.gov/missions/near/ |title=NEAR-Shoemaker |publisher=[[NASA]] |access-date=26 August 2015 |url-status=live |archive-url=https://web.archive.org/web/20150826173835/https://science.nasa.gov/missions/near/ |archive-date=26 August 2015 }}</ref> Since the early 20th century, there has been continuous human presence in Antarctica through [[Research stations in Antarctica|research stations]] and, since 2000, [[human presence in space|in space]] through habitation on the [[International Space Station]].<ref name="urlNASA">{{cite web |vauthors=Kraft R |title=JSC celebrates ten years of continuous human presence aboard the International Space Station |url=https://www.jsc.nasa.gov/jscfeatures/articles/000000945.html |publisher=[[Johnson Space Center]] |work=JSC Features |date=11 December 2010 |url-status=dead |archive-url=https://web.archive.org/web/20120216221409/https://www.jsc.nasa.gov/jscfeatures/articles/000000945.html |archive-date=16 February 2012 |access-date=13 February 2012 }}</ref>

[[File:Distribution-of-earths-mammals.png|thumb|upright=1.5| Humans and their domesticated animals represent 96% of all mammalian biomass on earth, whereas all wild mammals represent only 4%.<ref name="Bar-On" />]]

Estimates of the population at the time agriculture emerged in around 10,000 BC have ranged between 1 million and 15 million.<ref>{{cite book |vauthors=Tellier LN |url={{GBurl|id=cXuCjDbxC1YC|p=26}} |title=Urban world history: an economic and geographical perspective |date=2009 |isbn=978-2-7605-1588-8 |page=26 |publisher=Presses de l'Université du Québec |access-date=30 July 2022}}</ref><ref>{{cite book |vauthors=Thomlinson R |title=Demographic problems; controversy over population control. |date=1975 |edition=2nd |publisher=Dickenson Pub. Co |location=Ecino, CA |isbn=978-0-8221-0166-6}}</ref> Around 50–60 million people lived in the combined eastern and western [[Roman Empire]] in the 4th century AD.<ref>{{cite web |vauthors=Harl KW |date=1998 |title=Population estimates of the Roman Empire |url=https://www.tulane.edu/~august/H303/handouts/Population.htm |archive-url=https://web.archive.org/web/20160507061006/https://www.tulane.edu/~august/H303/handouts/Population.htm|archive-date=7 May 2016|access-date=8 December 2012|publisher=Tulane.edu}}</ref> [[Bubonic plague]]s, first recorded in the 6th century AD, reduced the population by 50%, with the [[Black Death]] killing 75–200 million people in [[Eurasia]] and [[North Africa]] alone.<ref>{{cite journal |vauthors=Zietz BP, Dunkelberg H | title = The history of the plague and the research on the causative agent Yersinia pestis |journal = International Journal of Hygiene and Environmental Health |volume=207 |issue=2 |pages=165–178 | date = February 2004 | pmid = 15031959 | doi = 10.1078/1438-4639-00259 |pmc=7128933}}</ref> Human population is believed to have reached one billion in 1800. It has since then increased exponentially, reaching two billion in 1930 and three billion in 1960, four in 1975, five in 1987 and six billion in 1999.<ref>{{cite news |url=https://news.bbc.co.uk/1/hi/sci/tech/411162.stm |access-date=5 February 2008 |work=BBC News |title=World's population reaches six billion |date=5 August 1999 |url-status=live |archive-url=https://web.archive.org/web/20080415053354/https://news.bbc.co.uk/1/hi/sci/tech/411162.stm |archive-date=15 April 2008 }}</ref> It passed seven billion in 2011<ref>{{Cite web |author=United Nations |title=World population to reach 8 billion on 15 November 2022 |url=https://www.un.org/en/desa/world-population-reach-8-billion-15-november-2022 |access-date=27 October 2022 |website=United Nations |language=en}}</ref> and passed eight billion in November 2022.<ref>{{cite journal |url=https://www.nature.com/articles/d41586-022-03792-4 |date=23 November 2022 |title=Eight billion people, SARS-CoV-2 ancestor and illegal fishing |journal=[[Nature (journal)|Nature]] |volume=611 |issue=641 |page=641 |doi=10.1038/d41586-022-03792-4 |bibcode=2022Natur.611..641. |s2cid=253764233 |access-date=26 January 2023 }}</ref> It took over two million years of [[prehistory|human prehistory]] and [[human history|history]] for the human population to reach one [[billion]] and only 207 years more to grow to 7 billion.<ref>{{cite web |date=27 October 2011 |title=World Population to Hit Milestone With Birth of 7 Billionth Person |url=https://www.pbs.org/newshour/bb/world-july-dec11-population1_10-27/ |url-status=live |archive-url=https://web.archive.org/web/20170924090953/http://www.pbs.org/newshour/bb/world-july-dec11-population1_10-27/ |archive-date=24 September 2017 |access-date=11 February 2018 |website=PBS NewsHour}}</ref> The combined [[Biomass (ecology)|biomass]] of the carbon of all the humans on Earth in 2018 was estimated at 60 million tons, about 10 times larger than that of all non-domesticated mammals.<ref name="Bar-On">{{cite journal | vauthors = Bar-On YM, Phillips R, Milo R | title = The biomass distribution on Earth | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 115 | issue = 25 | pages = 6506–6511 | date = June 2018 | pmid = 29784790 | pmc = 6016768 | doi = 10.1073/pnas.1711842115 | bibcode = 2018PNAS..115.6506B | doi-access = free }}</ref>

In 2018, 4.2 billion humans (55%) lived in urban areas, up from 751 million in 1950.<ref name="United Nations Department of Economic and Social Affairs (DESA)-2018">{{cite web|date=16 May 2018|title=68% of the world population projected to live in urban areas by 2050, says UN|work=United Nations Department of Economic and Social Affairs (DESA)|url=https://www.un.org/development/desa/en/news/population/2018-revision-of-world-urbanization-prospects.html|access-date=18 April 2021|language=en-US|archive-date=10 March 2021|archive-url=https://web.archive.org/web/20210310163911/https://www.un.org/development/desa/en/news/population/2018-revision-of-world-urbanization-prospects.html|url-status=live}}</ref> The most urbanized regions are Northern America (82%), Latin America (81%), Europe (74%) and Oceania (68%), with Africa and Asia having nearly 90% of the world's 3.4 billion rural population.<ref name="United Nations Department of Economic and Social Affairs (DESA)-2018" /> Problems for humans living in cities include various forms of pollution and crime,<ref>{{cite book |vauthors=Duhart DT |date=October 2000 |title=Urban, Suburban, and Rural Victimization, 1993–98 |publisher=[[U.S. Department of Justice]], Bureau of Justice Statistics |access-date=1 October 2006 |url=https://www.bjs.gov/content/pub/pdf/usrv98.pdf |archive-date=24 February 2013 |archive-url=https://web.archive.org/web/20130224090226/http://bjs.gov/content/pub/pdf/usrv98.pdf |url-status=live}}</ref> especially in inner city and suburban [[slum]]s. Humans have had a dramatic [[Human impact on the environment|effect on the environment]]. They are [[apex predator]]s, being rarely preyed upon by other species.<ref name="pmid24497513">{{cite journal |vauthors=Roopnarine PD |title=Humans are apex predators |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=111 |issue=9 |pages=E796 |date=March 2014 |pmid=24497513 |pmc=3948303 |doi=10.1073/pnas.1323645111 |bibcode=2014PNAS..111E.796R |doi-access=free}}</ref> Human [[population growth]], industrialization, land development, [[overconsumption]] and combustion of [[fossil fuels]] have led to [[Environmental degradation|environmental destruction]] and [[pollution]] that significantly contributes to the ongoing [[Holocene extinction|mass extinction]] of other forms of life.<ref name="Stokstad">{{cite web |url=https://www.science.org/content/article/landmark-analysis-documents-alarming-global-decline-nature |title=Landmark analysis documents the alarming global decline of nature |vauthors=Stokstad E |date=5 May 2019 |website=[[Science (journal)|Science]] |publisher=[[American Association for the Advancement of Science|AAAS]] |language=en |access-date=9 May 2021 |quote="For the first time at a global scale, the report has ranked the causes of damage. Topping the list, changes in land use{{snd}}principally agriculture{{snd}}that have destroyed habitat. Second, hunting and other kinds of exploitation. These are followed by climate change, pollution, and invasive species, which are being spread by trade and other activities. Climate change will likely overtake the other threats in the next decades, the authors note. Driving these threats are the growing human population, which has doubled since 1970 to 7.6 billion, and consumption. (Per capita of use of materials is up 15% over the past 5 decades.)" |archive-date=26 October 2021 |archive-url=https://web.archive.org/web/20211026232451/https://www.science.org/content/article/landmark-analysis-documents-alarming-global-decline-nature |url-status=live}}</ref><ref>{{cite journal |vauthors=Pimm S, Raven P, Peterson A, Sekercioglu CH, Ehrlich PR |date=July 2006 |title=Human impacts on the rates of recent, present, and future bird extinctions |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=103 |issue=29 |pages=10941–10946 |bibcode=2006PNAS..10310941P |doi=10.1073/pnas.0604181103 |pmc=1544153 |pmid=16829570 |doi-access=free}}</ref>