---
title: "Ice age"
chunk: 9/9
source: "https://en.wikipedia.org/wiki/Ice_age"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T03:39:28.674049+00:00"
instance: "kb-cron"
---

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. Human impact is now seen as possibly extending what would already be an unusually long warm period. Ice ages go through cycles of about 100,000 years, but the next one may well be avoided due to human carbon dioxide emissions. According to Stephen Barker of Cardiff University, without human interference, the next glaciation of the Earth would "occur within the next 11,000 years, and it would end in 66,000 years' time."
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 precessional cycle is around 21,000 years, the time it takes for the perihelion to move all the way around the tropical year.)

== See also ==

== References ==

=== Works cited ===
Montgomery, Keith (2010). "Development of the glacial theory, 1800–1870". Historical Simulation

== External links ==

Cracking the Ice Age Archived 2017-09-04 at the Wayback Machine from PBS
Rina Torchinsky (9 Aug 2021). "Scientists unveil 'best-preserved Ice Age animal ever found'". AccuWeather. Archived from the original on 9 August 2021. Retrieved 9 August 2021.
Raymo, M. (July 2011). "Overview of the Uplift-Weathering Hypothesis". Archived from the original on 2008-10-22.
Eduard Y. Osipov, Oleg M. Khlystov. Glaciers and meltwater flux to Lake Baikal during the Last Glacial Maximum. Archived 2016-03-12 at the Wayback Machine
Black, R. (9 January 2012). "Carbon emissions 'will defer Ice Age'". Science and Environment. BBC News. Archived from the original on 23 October 2018. Retrieved 20 June 2018.