Editing Ice age (section)

==Future ice ages==
{{Main|Next glacial period}}

Based on past estimates for interglacial durations of about 10,000 years, there was some concern in the 1970s that the next glacial period would be imminent.<ref>{{cite news |title=The Fiction Of Climate Science |url=https://www.forbes.com/2009/12/03/climate-science-gore-intelligent-technology-sutton.html |work=Forbes |date=4 December 2009}}</ref> [[Human impact on the environment|Human impact]] is now seen as possibly extending what would already be an unusually long warm period.<ref>{{cite news |title=Our next ice age is due in 10,000 years, but there's a catch |url=https://www.dw.com/en/earths-next-ice-age-is-due-in-10000-years-but-theres-a-catch/a-71786018 |work=Deutsche Welle |date=3 March 2025}}</ref><ref>{{cite news |title=Study Shows How Earth’s Orbit Affects Ice Ages |url=https://learningenglish.voanews.com/a/study-shows-how-earth-s-orbit-affects-ice-ages/7997495.html |work=[[Voice of America]] |date=10 March 2025}}</ref> Ice ages go through cycles of about 100,000 years, but the next one may well be avoided due to human carbon dioxide emissions.<ref name="PIK2016" />

A 2015 report by the Past Global Changes Project says simulations show that a new glaciation is unlikely to happen within the next approximately 50,000 years, before the next strong drop in Northern Hemisphere summer insolation occurs "if either atmospheric {{CO2}} concentration
remains above 300 ppm or cumulative carbon emissions exceed 1000 Pg C" (i.e. 1,000 gigatonnes carbon). "Only for an atmospheric {{CO2}} content below the preindustrial level may a glaciation occur within the next 10 ka. ... Given the continued anthropogenic {{CO2}} emissions, glacial inception is very unlikely to occur in the next 50 ka, because the timescale for {{CO2}} and temperature reduction toward unperturbed values in the absence of active removal is very long [IPCC, 2013], and only weak precessional forcing occurs in the next two precessional cycles." (A [[Milankovitch cycles#Apsidal precession|precessional cycle]] is around 21,000 years, the time it takes for the [[perihelion]] to move all the way around the [[tropical year]].)<ref>{{Cite journal|last=Interglacial Working Group Of PAGES|title=Interglacials Of The Last 800,000 years|url=http://discovery.ucl.ac.uk/1474024/1/Past%20Interglacials%20Working%20Group%20of%20PAGES%20Interglacials%20of%20the%20last%20800%2C000%20years%20VoR.pdf |bibcode-access=free |hdl-access=free |journal=Reviews of Geophysics|date=November 20, 2015|volume=54|issue=1|pages=162–219|bibcode=2016RvGeo..54..162P|doi=10.1002/2015RG000482|hdl=2078.1/175429|doi-access=free |via=UCL Discovery |url-status=live |archive-url= https://web.archive.org/web/20180718233716/http://discovery.ucl.ac.uk/1474024/1/Past%20Interglacials%20Working%20Group%20of%20PAGES%20Interglacials%20of%20the%20last%20800%2C000%20years%20VoR.pdf |archive-date= Jul 18, 2018 }}</ref>