Earth

== Human geography ==
{{Main|Human geography}}
{{See also|World}}
[[File:Earth's City Lights by DMSP, 1994-1995 (large).jpg|thumb|upright=1.3|A composite image of [[light pollution|artificial light emissions]] at night on a map of Earth]]
Originating from earlier [[primate]]s in Eastern Africa 300,000 years ago [[History of human migration|humans have since been migrating]] and with the advent of agriculture in the 10th millennium BC increasingly [[Sedentism|settling]] Earth's land.<ref>{{Cite web |title=Introduction to Human Evolution {{!}} The Smithsonian Institution's Human Origins Program |url=http://humanorigins.si.edu/education/introduction-human-evolution |access-date=2023-11-09 |website=humanorigins.si.edu |date=11 July 2022 |language=en}}</ref> In the 20th century [[Antarctica]] had been the last continent to see a first and until today limited human presence.

[[World population|Human population]] has since the 19th century grown exponentially to seven billion in the early 2010s,<ref>{{cite web |url=https://news.yahoo.com/various-7-billionth-babies-celebrated-worldwide-064439018.html |title=Various '7 billionth' babies celebrated worldwide |date=31 October 2011|agency=Associated Press|access-date=31 October 2011 |url-status=dead |archive-url=https://web.archive.org/web/20111031182613/http://news.yahoo.com/various-7-billionth-babies-celebrated-worldwide-064439018.html |work=Yahoo News |last1=Gomez |first1=Jim |last2=Sullivan|first2=Tim|archive-date=31 October 2011}}</ref> and is projected to peak at around ten billion in the second half of the 21st century.<ref name="Harvey-2020">{{Cite news |last=Harvey |first=Fiona |date=15 July 2020 |title=World population in 2100 could be 2 billion below UN forecasts, study suggests |language=en-GB |work=The Guardian |url=https://www.theguardian.com/world/2020/jul/15/world-population-in-2100-could-be-2-billion-below-un-forecasts-study-suggests |url-access=registration |access-date=18 September 2020 |issn=0261-3077}}</ref> Most of the growth is expected to take place in [[sub-Saharan Africa]].<ref name="Harvey-2020" />

Distribution and [[Population density#Human population density|density of human population]] varies greatly around the world with the majority living in south to eastern Asia and 90% inhabiting only the [[Northern Hemisphere]] of Earth,<ref>{{Cite web |url=https://www.businessinsider.com/90-of-people-live-in-the-northern-hemisphere-2012-5 |title=MAP OF THE DAY: Pretty Much Everyone Lives In The Northern Hemisphere |date=4 May 2012 |work=Business Insider|last1=Lutz|first1=Ashley|access-date=5 January 2019}}</ref> partly due to the [[Land hemisphere|hemispherical predominance of the world's land mass]], with 68% of the world's land mass being in the Northern Hemisphere.<ref>{{Cite web |url=http://phl.upr.edu/library/notes/distributionoflandmassesofthepaleo-earth |title=Distribution of landmasses of the Paleo-Earth |first1=Abel |last1=Méndez |author-link1=Abel Méndez |date=6 July 2011 |publisher=University of Puerto Rico at Arecibo |access-date=5 January 2019 |archive-date=6 January 2019 |archive-url=https://web.archive.org/web/20190106010959/http://phl.upr.edu/library/notes/distributionoflandmassesofthepaleo-earth |url-status=dead }}</ref> Furthermore, since the 19th century humans have increasingly converged into urban areas with the majority living in urban areas by the 21st century.<ref name="OWID_urbanization_2019" />

Beyond Earth's surface humans have lived on a temporary basis, with only special purpose deep [[underground living|underground]] and [[underwater living|underwater]] presence, and a few [[space station]]s. Human population virtually completely remains on Earth's surface, fully depending on Earth and the environment it sustains. Since the second half of the 20th century, some hundreds of humans have temporarily stayed beyond Earth, a tiny fraction of whom have reached another celestial body, the Moon.<ref name="shayler_vis2005" /><ref>{{Cite news|last=Holmes|first=Oliver|date=19 November 2018 |title=Space: how far have we gone – and where are we going?|language=en-GB|work=The Guardian|url=https://www.theguardian.com/science/2018/nov/19/space-how-far-have-we-gone-and-where-are-we-going|access-date=10 October 2020|issn=0261-3077}}</ref>

Earth has been subject to extensive human settlement, and humans have developed diverse societies and cultures. Most of Earth's land has been territorially claimed since the 19th century by [[sovereign state]]s (countries) separated by [[Border|political borders]], and [[List of sovereign states|205 such states]] exist today,<ref>{{cite web | title = Member States <nowiki>|</nowiki> United Nations | url = https://www.un.org/en/about-us/member-states | publisher = United Nations | access-date = 2024-01-03 | archive-url = https://web.archive.org/web/20230301201032/https://www.un.org/en/about-us/member-states | archive-date = 2023-03-01 | url-status=live}}</ref> with only parts of Antarctica and a few small regions [[Terra nullius|remaining unclaimed]].<ref>{{cite book|last1=Lloyd|first1=John|author-link1=John Lloyd (producer)|title=The Discretely Plumper Second QI Book of General Ignorance|last2=Mitchinson|first2=John|author-link2=John Mitchinson (researcher)|publisher=Faber & Faber |year=2010|isbn=978-0-571-29072-7|pages=116–117}}</ref> Most of these states together form the United Nations, the leading worldwide [[intergovernmental organization]],<ref>{{cite book|last1=Smith|first1=Courtney B.|url=https://www.rienner.com/uploads/47d958f8700e6.pdf|title=Politics and Process at the United Nations: The Global Dance|publisher=Lynne Reiner|year=2006|isbn=978-1-58826-323-0|pages=1–4}}</ref> which extends human governance [[Law of the Sea|over the ocean]] and [[Antarctic Treaty System|Antarctica]], and therefore all of Earth.

=== Natural resources and land use ===
{{Main|Natural resource|Land use}}
[[File:Global-land-use-graphic.png|thumb|upright=1.3|Earth's land use for human agriculture]]
Earth has resources that have been exploited by humans.<ref>{{cite news|title=What are the consequences of the overexploitation of natural resources?|work=[[Iberdrola]] |url=https://www.iberdrola.com/environment/overexploitation-of-natural-resources|access-date=28 June 2019}}</ref> Those termed [[non-renewable resource]]s, such as [[fossil fuel]]s, are only replenished over geological timescales.<ref>{{cite journal|date=20 April 2016|title=13. Exploitation of Natural Resources|url=https://www.eea.europa.eu/publications/92-826-5409-5/page013new.html|journal=[[European Environment Agency]]|publisher=[[European Union]]|access-date=28 June 2019}}</ref> Large deposits of fossil fuels are obtained from Earth's crust, consisting of coal, petroleum, and natural gas.<ref>{{cite news|last=Huebsch|first=Russell|date=29 September 2017|title=How Are Fossil Fuels Extracted From the Ground?|work=Sciencing|publisher=[[Leaf Group]] Media|url=https://sciencing.com/how-are-fossil-fuels-extracted-from-the-ground-12227026.html |access-date=28 June 2019}}</ref> These deposits are used by humans both for energy production and as feedstock for chemical production.<ref>{{cite web |title=Electricity generation – what are the options?|url=http://www.world-nuclear.org/nuclear-basics/electricity-generation-what-are-the-options.aspx|access-date=28 June 2019 |work=[[World Nuclear Association]]}}</ref> Mineral [[ore]] bodies have also been formed within the crust through a process of [[ore genesis]], resulting from actions of [[magmatism]], erosion, and plate tectonics.<ref>{{cite journal|last1=Brimhall|first1=George|date=May 1991|title=The Genesis of Ores|url=https://www.jstor.org/stable/24936905 |journal=Scientific American |publisher=Nature America|volume=264|pages=84–91|doi=10.1038/scientificamerican0591-84|jstor=24936905|access-date=13 October 2020 |number=5 |bibcode=1991SciAm.264e..84B}}</ref> These metals and other elements are extracted by mining, a process which often brings environmental and health damage.<ref>{{Cite book|last=Lunine|first=Jonathan I. |author-link=Jonathan Lunine|title=Earth: Evolution of a Habitable World|publisher=Cambridge University Press |year=2013 |isbn=978-0-521-61519-8 |edition=second|pages=292–294}}</ref>

Earth's biosphere produces many useful biological products for humans, including food, wood, [[pharmaceutical]]s, oxygen, and the recycling of organic waste. The land-based ecosystem depends upon [[topsoil]] and fresh water, and the oceanic ecosystem depends on dissolved nutrients washed down from the land.<ref name="science299_5607_673" /> In 2019, {{convert|39|e6km2|e6sqmi|abbr=unit}} of Earth's land surface consisted of forest and woodlands, {{convert|12|e6km2|e6sqmi|abbr=unit}} was shrub and grassland, {{convert|40|e6km2|e6sqmi|abbr=unit}} were used for animal feed production and grazing, and {{convert|11|e6km2|e6sqmi|abbr=unit}} were cultivated as croplands.<ref name="OWID_2019" /> Of the 12{{En dash}}14% of ice-free land that is used for croplands, 2 [[percentage point]]s were irrigated in 2015.<ref>{{Cite book |author=IPCC |title=IPCC Special Report on Climate Change and Land |year=2019 |page=8 |chapter=Summary for Policymakers |author-link=IPCC <!-- |display-authors= 4 --> |chapter-url=https://www.ipcc.ch/site/assets/uploads/sites/4/2019/12/02_Summary-for-Policymakers_SPM.pdf}}</ref> Humans use [[building material]]s to construct shelters.<ref>{{cite book |last1=Tate|first1=Nikki|author-link=Nikki Tate|title=Take Shelter: At Home Around the World|last2=Tate-Stratton|first2=Dani|year=2014|publisher=Orca Book Publishers|isbn=978-1-4598-0742-6|page=6}}</ref>

=== Humans and the environment ===
{{Main|Human impact on the environment|Climate change}}
[[File:Global Temperature And Forces With Fahrenheit.svg|alt=The graph from 1880 to 2020 shows natural drivers exhibiting fluctuations of about 0.3 degrees Celsius. Human drivers steadily increase by 0.3 degrees over 100 years to 1980, then steeply by 0.8 degrees more over the past 40 years.|thumb|upright=1.3|Change in average surface air temperature and drivers for that change. Human activity has caused increased temperatures, with natural forces adding some variability.<ref>{{Cite book |author=IPCC |author-link=IPCC |year=2021 |title=Climate Change 2021: The Physical Science Basis |series=Contribution of Working Group I to the [[IPCC Sixth Assessment Report|Sixth Assessment Report]] of the Intergovernmental Panel on Climate Change |display-editors=4 |editor1-first=V. |editor1-last=Masson-Delmotte |editor2-first=P. |editor2-last=Zhai |editor3-first=A. |editor3-last=Pirani |editor4-first=S. L. |editor4-last=Connors |editor5-first=C. |editor5-last=Péan |editor6-first=S. |editor6-last=Berger |editor7-first=N. |editor7-last=Cau |editor8-first=Y. |editor8-last=Chen |editor9-first=L. |editor9-last=Goldfarb |editor10-first=M. I. |editor10-last=Gomis |publisher=Cambridge University Press (In Press) |place=Cambridge, United Kingdom and New York, NY, US |url=https://www.ipcc.ch/report/ar6/wg1/downloads/report/IPCC_AR6_WGI_Full_Report.pdf |at=SPM-7}}</ref>]]

Human activities have impacted Earth's environments. Through activities such as the burning of fossil fuels, humans have been increasing the amount of [[greenhouse gas]]es in the atmosphere, altering [[Earth's energy budget]] and climate.<ref name=ConsensusOnConsensus /><ref>{{Cite web |url=https://earthobservatory.nasa.gov/features/EnergyBalance |title=Climate and Earth's Energy Budget |first1=Rebecca|last1=Lindsey |date=14 January 2009 |website=Earth Observatory|publisher=[[NASA]]|language=en |access-date=19 December 2021}}</ref> It is estimated that global temperatures in the year 2020 were {{convert|1.2|C-change}} warmer than the preindustrial baseline.<ref>{{cite web|date=14 January 2021|title=The State of the Global Climate 2020|url=https://public-old.wmo.int/en/our-mandate/climate/wmo-statement-state-of-global-climate|archive-url=https://web.archive.org/web/20231129232510/https://public-old.wmo.int/en/our-mandate/climate/wmo-statement-state-of-global-climate|url-status=dead|archive-date=29 November 2023|access-date=3 March 2021|website=World Meteorological Organization |language=en}}</ref> This increase in temperature, known as [[global warming]], has contributed to the [[Retreat of glaciers since 1850|melting of glaciers]], [[Sea level rise|rising sea levels]], increased risk of drought and wildfires, and migration of species to colder areas.<ref name="Global Warming Effects" />

The concept of [[planetary boundaries]] was introduced to quantify humanity's impact on Earth. Of the nine identified boundaries, five have been crossed: [[Biodiversity loss|Biosphere integrity]], climate change, chemical pollution, destruction of wild habitats and the [[nitrogen cycle]] are thought to have passed the safe threshold.<ref name="Boundaries">{{cite web |title=We've crossed four of nine planetary boundaries. What does this mean? |website=[[Mongabay]] |last1=DiGirolamo |first1=Mike |date=8 September 2021 |url=https://news.mongabay.com/2021/09/weve-crossed-four-of-nine-planetary-boundaries-what-does-this-mean/ |access-date=27 January 2022}}</ref><ref>{{cite news |last1=Carrington |first1=Damien |title=Chemical pollution has passed safe limit for humanity, say scientists |url=https://www.theguardian.com/environment/2022/jan/18/chemical-pollution-has-passed-safe-limit-for-humanity-say-scientists |work=The Guardian |date=18 January 2022 |language=en}}</ref> As of 2018, no country meets the basic needs of its population without transgressing planetary boundaries. It is thought possible to provide all basic physical needs globally within sustainable levels of resource use.<ref>{{Cite journal|last1=O'Neill|first1=Daniel W.|last2=Fanning|first2=Andrew L.|last3=Lamb|first3=William F.|last4=Steinberger|first4=Julia K.|author4-link=Julia Steinberger|date=2018|title=A good life for all within planetary boundaries|url=https://www.nature.com/articles/s41893-018-0021-4|journal=Nature Sustainability |language=en |volume=1 |issue=2 |pages=88–95 |doi=10.1038/s41893-018-0021-4|bibcode=2018NatSu...1...88O |s2cid=169679920|issn=2398-9629}}</ref>