Editing Little Ice Age (section)

===Ocean circulation===
[[File:Ocean circulation conveyor belt.jpg|thumb|upright=1.6|Thermohaline circulation or Oceanic conveyor belt illustrated]]
In the early 2000s, a slowing of [[thermohaline circulation]] was proposed as an explanation for the LIA,<ref name="Broecker00">{{cite journal |last1=Broecker |first1=Wallace S. |year=2000 |title=Was a change in thermohaline circulation responsible for the Little Ice Age? |journal=[[Proceedings of the National Academy of Sciences of the United States of America]] |volume=97 |issue=4 |pages=1339–1342 |bibcode=2000PNAS...97.1339B |doi=10.1073/pnas.97.4.1339 |jstor=121471 |pmc=34299 |pmid=10677462 |doi-access=free}}</ref><ref name=":0"/><ref>{{cite web |url=https://science.nasa.gov/headlines/y2004/05mar_arctic.htm |title=A Chilling Possibility – NASA Science |publisher=Science.nasa.gov |access-date=24 June 2013 |url-status=dead |archive-url=https://web.archive.org/web/20100317001142/http://science.nasa.gov/headlines/y2004/05mar_arctic.htm |archive-date=17 March 2010  }}</ref> specifically, through the weakening of the [[North Atlantic Gyre]].<ref>{{Cite journal |last1=Lapointe |first1=Francois |last2=Bradley |first2=Raymond S. |date=2021-12-17 |title=Little Ice Age abruptly triggered by intrusion of Atlantic waters into the Nordic Seas |journal=[[Science Advances]] |volume=7 |issue=51 |pages=eabi8230 |doi=10.1126/sciadv.abi8230 |issn=2375-2548 |pmc=8673760 |pmid=34910526 |bibcode=2021SciA....7.8230L }}</ref><ref name="Hopkin2006">{{cite web |author=Hopkin, Michael |date=29 November 2006 |title=Gulf Stream weakened in 'Little Ice Age' |url=http://www.bioedonline.org/news/news.cfm?art=2966 |access-date=1 February 2019 |website=BioEd Online}}</ref> The circulation could have been interrupted by the introduction of a large amount of fresh water into the North Atlantic and might have been caused by a period of warming before the LIA that is known as the [[Medieval Warm Period]].<ref name=Fagan/><ref name="Villanueva2009">{{cite news |last=Villanueva |first= John Carl |title=Little Ice Age |work= Universe Today |url=http://www.universetoday.com/guide-to-space/earth/little-ice-age/ |date=19 October 2009 |access-date=22 September 2010}}</ref><ref>{{cite journal |last1=Pittenger |first1= Richard F. |last2=Gagosian |first2= Robert B. |title=Global Warming Could Have a Chilling Effect on the Military |url=http://handle.dtic.mil/100.2/ADA422382  |archive-url=https://web.archive.org/web/20120531100736/http://handle.dtic.mil/100.2/ADA422382  |url-status=dead  |archive-date=31 May 2012  |format=PDF |journal=Defense Horizons  |volume= 33  |date=October 2003 |access-date=22 September 2010 }}</ref> Some researchers have thus classified the LIA as a [[Bond event]].<ref>{{cite book |last1=Banerji |first1=Upasana S. |url=https://www.sciencedirect.com/book/9780323900850/holocene-climate-change-and-environment |title=Holocene Climate Change and Environment |last2=Padmalal |first2=D. |publisher=Elsevier |year=2021 |isbn=978-0-323-90085-0 |editor-last1=Kumaran |editor-first1=Navnith |location= |pages=293–339 |chapter=12 – Bond events and monsoon variability during Holocene—Evidence from marine and continental archives |doi=10.1016/B978-0-323-90085-0.00016-4 |s2cid=244441781 |access-date=9 September 2023 |editor-last2=Damodara |editor-first2=Padmalal |chapter-url=https://www.sciencedirect.com/science/article/abs/pii/B9780323900850000164}}</ref> In 2005 there was some concern that a [[shutdown of thermohaline circulation]] could happen again as a result of the present warming.<ref name="Leake2005">{{cite news| url=http://www.timesonline.co.uk/tol/news/uk/article520013.ece | work=The Times | location=London | title=Britain faces big chill as ocean current slows | first=Jonathan | last=Leake | date=8 May 2005 | access-date=11 May 2010 | url-status=dead | archive-date=February 8, 2007 | archive-url=https://web.archive.org/web/20070208064001/http://www.timesonline.co.uk/tol/news/uk/article520013.ece}}</ref><ref>{{Scientific American Frontiers|15| 5 |title=Hot Planet – Cold Comfort |url=https://www.pbs.org/saf/1505/index.html |network=PBS |date=16 February 2005 |transcript=Only a Little Ice Age |transcript-url=https://www.pbs.org/saf/1505/segments/1505-3.htm}}</ref>

More recent research indicates that the overall Atlantic Meridional Overturning Circulation may already be weaker now than it was during the LIA,<ref name="RahmstorfBox2015">{{cite journal |last1=Rahmstorf |first1=Stefan |last2=Box |first2=Jason E. |last3=Feulner |first3=Georg |last4=Mann |first4=Michael E. |last5=Robinson |first5=Alexander |last6=Rutherford |first6=Scott |last7=Schaffernicht |first7=Erik J. |year=2015 |title=Exceptional twentieth-century slowdown in Atlantic Ocean overturning circulation |url=https://eprints.ucm.es/32657/1/robinson10postprint.pdf |archive-url=https://web.archive.org/web/20160909080138/http://eprints.ucm.es/32657/1/robinson10postprint.pdf |archive-date=2016-09-09 |url-status=live |journal=[[Nature Climate Change]] |volume=5 |issue=5 |pages=475–480 |bibcode=2015NatCC...5..475R |doi=10.1038/nclimate2554 |issn=1758-678X }} {{Closed access}} [http://wedocs.unep.org/bitstream/handle/20.500.11822/17802/Exceptional_twentiethcentury_slowdown_in_Atla.pdf PDF in UNEP Document Repository] {{Webarchive|url=https://web.archive.org/web/20190712144829/http://wedocs.unep.org/bitstream/handle/20.500.11822/17802/Exceptional_twentiethcentury_slowdown_in_Atla.pdf |date=12 July 2019 }}</ref><ref name="Thorn2018">{{Cite journal |last1=Thornalley |first1=David JR |display-authors=etal  |date=11 April 2018 |title=Anomalously weak Labrador Sea convection and Atlantic overturning during the past 150 years |url=https://www.nature.com/articles/s41586-018-0007-4 |journal=[[Nature (journal)|Nature]] |volume=556 |issue=7700 |pages=227–230 |doi=10.1038/s41586-018-0007-4 |pmid=29643484 |bibcode=2018Natur.556..227T |s2cid=4771341 |access-date=3 October 2022}}</ref> or perhaps even over the past millennium.<ref>{{Cite journal |last1=Caesar |first1=L. |last2=McCarthy |first2=G.D. |last3=Thornalley |first3=D. J. R. |last4=Cahill |first4=N. |last5=Rahmstorf |first5=S. |date=25 February 2021 |title=Current Atlantic Meridional Overturning Circulation weakest in last millennium |url=https://www.nature.com/articles/s41561-021-00699-z |journal=Nature Geoscience |volume=14 |issue=3 |pages=118–120 |doi=10.1038/s41561-021-00699-z |bibcode=2021NatGe..14..118C |s2cid=232052381 |access-date=3 October 2022}}</ref> While there is still a robust debate about the present-day AMOC strength,<ref>{{Cite journal |last1=Kilbourne |first1=Kelly Halimeda |last2=et |first2=al. |date=17 February 2022 |title=Atlantic circulation change still uncertain |url=https://www.nature.com/articles/s41561-022-00896-4 |journal=[[Nature Geoscience]] |volume=15 |issue=3 |pages=165–167 |doi=10.1038/s41561-022-00896-4 |bibcode=2022NatGe..15..165K |s2cid=246901665 |access-date=3 October 2022|hdl=2117/363518 |hdl-access=free }}</ref><ref>{{Cite journal |last1=Caesar |first1=L. |last2=McCarthy |first2=G. D. |last3=Thornalley |first3=D. J. R. |last4=Cahill |first4=N. |last5=Rahmstorf |first5=S. |date=17 February 2022 |title=Reply to: Atlantic circulation change still uncertain |url=https://www.nature.com/articles/s41561-022-00897-3 |journal=[[Nature Geoscience]] |volume=15 |issue=3 |pages=168–170 |bibcode=2022NatGe..15..168C |doi=10.1038/s41561-022-00897-3 |s2cid=246901654 |access-date=3 October 2022}}</ref><ref>{{Cite journal |last1=Latif |first1=Mojib |last2=Sun |first2=Jing |last3=Visbeck |first3=Martin |last4=Bordbar |date=25 April 2022 |title=Natural variability has dominated Atlantic Meridional Overturning Circulation since 1900 |journal=[[Nature Climate Change]] |volume=12 |issue=5 |pages=455–460 |doi=10.1038/s41558-022-01342-4|bibcode=2022NatCC..12..455L |s2cid=248385988 |doi-access=free }}</ref> these findings make the link between AMOC and the LIA unlikely. However, some research instead suggests that a far more localized disruption of the [[North Atlantic Current|North Subpolar Gyre]] convection was involved in the LIA.<ref>{{Cite journal |last1=Arellano-Nava |first1=Beatriz |last2=Halloran |first2=Paul R. |last3=Boulton |first3=Chris A. |last4=Scourse  |first4=James |last5=Butler |first5=Paul G. |last6=Reynolds |first6=David J. |last7=Lenton |first7=Timothy  |date=25 August 2022 |title=Destabilisation of the Subpolar North Atlantic prior to the Little Ice Age |journal=[[Nature Communications]] |volume=13 |issue=1 |page=5008 |doi=10.1038/s41467-022-32653-x |pmid=36008418 |pmc=9411610 |bibcode=2022NatCo..13.5008A |s2cid=251842966 }}</ref> This is potentially relevant for the near future, as a minority of [[climate model]]s project a permanent collapse of this convection under some scenarios of future [[climate change]].<ref>{{Cite journal |last1=Swingedouw |first1=Didier |last2=Bily |first2=Adrien |last3=Esquerdo |first3=Claire |last4=Borchert |first4=Leonard F. |last5=Sgubin |first5=Giovanni |last6=Mignot |first6=Juliette |last7=Menary |first7=Matthew |date=2021 |title=On the risk of abrupt changes in the North Atlantic subpolar gyre in CMIP6 models |url=https://nyaspubs.onlinelibrary.wiley.com/doi/10.1111/nyas.14659 |journal=[[Annals of the New York Academy of Sciences]] |volume=1504 |issue=1 |pages=187–201 |bibcode=2021NYASA1504..187S |doi=10.1111/nyas.14659 |pmid=34212391 |s2cid=235712017|hdl=10447/638022 |hdl-access=free }}</ref><ref>{{Cite journal |last1=Armstrong McKay |first1=David |last2=Abrams |first2=Jesse |last3=Winkelmann |first3=Ricarda |last4=Sakschewski |first4=Boris |last5=Loriani |first5=Sina |last6=Fetzer |first6=Ingo |last7=Cornell |first7=Sarah |last8=Rockström |first8=Johan |last9=Staal |first9=Arie |last10=Lenton |first10=Timothy |date=9 September 2022 |title=Exceeding 1.5°C global warming could trigger multiple climate tipping points |url=https://www.science.org/doi/10.1126/science.abn7950 |journal=[[Science (journal)|Science]] |language=en |volume=377 |issue=6611 |pages=eabn7950 |doi=10.1126/science.abn7950 |issn=0036-8075 |pmid=36074831 |s2cid=252161375 |hdl=10871/131584|hdl-access=free }}</ref><ref>{{Cite web |last=Armstrong McKay |first=David |date=9 September 2022 |title=Exceeding 1.5°C global warming could trigger multiple climate tipping points – paper explainer |url=https://climatetippingpoints.info/2022/09/09/climate-tipping-points-reassessment-explainer/ |access-date=2 October 2022 |website=climatetippingpoints.info |language=en}}</ref>