Climate commitment: Difference between revisions

Revision as of 10:01, 27 May 2025

Latest revision as of 16:41, 7 July 2025

(One intermediate revision by one other user not shown)

Line 1:

{{short description|Unavoidable future climate change due to inertial effects}}

[[File:1979- Radiative forcing - climate change - global warming - EPA NOAA.svg |thumb|right|upright=1.5 |The ongoing buildup of [[IPCC list of greenhouse gases|long-lived greenhouse gases]] in Earth's atmosphere, whose warming influence has nearly doubled since 1979, shows mankind's influence on the global climate.<ref name=NOAA_AGGI_2023>{{cite web |title=The NOAA Annual Greenhouse Gas Index (AGGI) |url=https://gml.noaa.gov/aggi/aggi.html |website=NOAA.gov |publisher=National Oceanic and Atmospheric Administration (NOAA) |archive-url=https://web.archive.org/web/20241005195609/https://gml.noaa.gov/aggi/aggi.html |archive-date=5 October 2024 |date=2024 |url-status=live }}</ref><ref>{{Cite web |url=https://www.globalchange.gov/browse/indicators/annual-greenhouse-gas-index |title=Annual Greenhouse Gas Index |publisher=U.S. Global Change Research Program |archive-date=21 April 2021 |archive-url=https://web.archive.org/web/20210421143115/https://www.globalchange.gov/browse/indicators/annual-greenhouse-gas-index |url-status=livedead }}</ref><ref>{{Cite web |url=https://www.esrl.noaa.gov/gmd/aggi/ |title=The NOAA Annual Greenhouse Gas Index (AGGI) - An Introduction |publisher=[[NOAA]] Global Monitoring Laboratory/Earth System Research Laboratories |access-date=2 March 2023}}</ref>]]

'''Climate commitment''' describes the fact that Earth's [[climate]] reacts with a delay to influencing factors ("[[climate forcing]]s") such as the growth and the greater presence of [[greenhouse gas]]es. Climate commitment studies attempt to assess the amount of future [[global warming]] that is "committed" under the assumption of some constant or some evolving level of forcing. The constant level often used for illustrative purposes is that due to [[carbon dioxide|{{CO2}}]] doubling or quadrupling relative to the pre-industrial level; or the present level of forcing.

{{clear}}

Line 23:

== Models ==

{{main|global climate model}}

Recent [[model (abstract)|model]]s forecast that even in the unlikely event of greenhouse gases stabilizing at present levels, the Earth would warm by an additional 0.5°C by 2100, a similar rise in temperature to that seen during the 20th century. In 2050, as much as 64% of that commitment would be due to ''past'' natural forcings. Over time, their contribution compared to the human influence will diminish. Overall, the warming commitment at 2005 greenhouse gas levels could exceed 1°C.<ref>{{cite journal |last=Wigley |first=T. M. L. |title=The Climate Change Commitment |journal=Science |volume=307 |issue=5716 |pages=1766–9 |date=17 March 2005 |doi=10.1126/science.1103934 |pmid=15774756 |url=ftp://ftp.soest.hawaii.edu/coastal/Climate%20Articles/Wigley_2005%20Sea%20level%20commitment.pdf |archive-url=https://web.archive.org/web/20171011182247/ftp://ftp.soest.hawaii.edu/coastal/Climate%20Articles/Wigley_2005%20Sea%20level%20commitment.pdf |archive-date=2017-10-11 |url-status=dead |bibcode=2005Sci...307.1766W }}</ref> As ocean waters expand in response to this warming, global [[sea level]]s would mount by about 10 centimeters during that time. These models do not take into account [[ice cap]] and [[glacier]] melting; including those [[climate feedback]] effects would give a 1–1.5°C estimated temperature increase.<ref>{{cite journal |url= http://www.nature.com/news/2005/050314/full/050314-13.html |title= Oceans extend effects of climate change |first=Deirdre |last=Lockwood |date= 2005-05-17 |journal=Nature News |doi=10.1038/news050314-13|url-access=subscription }} </ref>

== History ==