Editing Holocene (section)

==Overview==
The [[International Commission on Stratigraphy]] has defined the Holocene as starting approximately 11,700 years before 2000 [[Common Era|CE]] (11,650 [[Radiocarbon calibration|cal]] years [[Before present|BP]], or 9,700 BCE).<ref name="Walker, M. 2009. pp. 3"/> The Subcommission on Quaternary Stratigraphy (SQS) regards the term 'recent' as an incorrect way of referring to the Holocene, preferring the term 'modern' instead to describe current processes. It also observes that the term 'Flandrian' may be used as a synonym for Holocene, although it is becoming outdated.<ref>{{Citation |last1=Gibbard |first1=P. L. |title=Chapter 30 – The Quaternary Period |date=2020-01-01 |work=Geologic Time Scale 2020 |pages=1217–1255 |editor-last=Gradstein |editor-first=Felix M. |url=https://www.sciencedirect.com/science/article/pii/B9780128243602000309 |access-date=2022-04-21 |publisher=Elsevier |language=en |isbn=978-0-12-824360-2 |last2=Head |first2=M. J. |editor2-last=Ogg |editor2-first=James G. |editor3-last=Schmitz |editor3-first=Mark D. |editor4-last=Ogg |editor4-first=Gabi M.}}.</ref> The International Commission on Stratigraphy, however, considers the Holocene to be an epoch following the [[Pleistocene]] and specifically following the [[last glacial period]]. Local names for the [[Late Pleistocene|last glacial period]] include the [[Wisconsin glaciation|Wisconsinan]] in [[North America]],<ref name=Clayton1982>{{cite journal |last1=Clayton |first1=Lee |last2=Moran |first2=Stephen R. |title=Chronology of late wisconsinan glaciation in middle North America |journal=[[Quaternary Science Reviews]] |year=1982 |volume=1 |issue=1 |pages=55–82 |doi=10.1016/0277-3791(82)90019-1 |bibcode=1982QSRv....1...55C }}</ref> the [[Weichselian glaciation|Weichselian]] in Europe,<ref name=Svendsen1999>{{cite journal |last1=Svendsen |first1=John Inge |last2=Astakhov |first2=Valery I. |last3=Bolshiyanov |first3=Dimitri Yu. |last4=Demidov |first4=Igor |last5=Dowdeswell |first5=Julian A. |last6=Gataullin |first6=Valery |last7=Hjort |first7=Christian |last8=Hubberten |first8=Hans W. |last9=Larsen |first9=Eiliv |last10=Mangerud |first10=Jan |last11=Melles |first11=Martin |last12=Moller |first12=Per |last13=Saarnisto |first13=Matti |last14=Siegert |first14=Martin J. |title=Maximum extent of the Eurasian ice sheets in the Barents and Kara Sea region during the Weichselian |url=http://www.folk.uib.no/ngljm/PDF_files/SVENDSEN99.PDF |journal=[[Boreas (journal)|Boreas]] |date=March 1999 |volume=28 |issue=1 |pages=234–242 |doi=10.1111/j.1502-3885.1999.tb00217.x |bibcode=1999Borea..28..234S |s2cid=34659675 |access-date=2018-02-11 |archive-date=2018-02-12 |archive-url=https://web.archive.org/web/20180212083433/http://www.folk.uib.no/ngljm/PDF_files/SVENDSEN99.PDF |url-status=live }}</ref> the Devensian in Britain,<ref name=Eyles1989>{{cite journal |last1=Eyles |first1=Nicholas |last2=McCabe |first2=A. Marshall |title=The Late Devensian (<22,000 BP) Irish Sea Basin: The sedimentary record of a collapsed ice sheet margin |journal=[[Quaternary Science Reviews]] |year=1989 |volume=8 |issue=4 |pages=307–351 |doi=10.1016/0277-3791(89)90034-6 |bibcode=1989QSRv....8..307E }}</ref> the [[Llanquihue glaciation|Llanquihue]] in Chile<ref name="Denton1999">{{cite journal |last1=Denton |first1=G. H. |last2=Lowell |first2=T. V. |last3=Heusser |first3=C. J. |last4=Schluchter |first4=C. |last5=Andersern |first5=B. G. |last6=Heusser |first6=Linda E. |last7=Moreno |first7=P. I. |last8=Marchant |first8=D. R. |year=1999 |title=Geomorphology, stratigraphy, and radiocarbon chronology of LlanquihueDrift in the area of the Southern Lake District, Seno Reloncavi, and Isla Grande de Chiloe, Chile |url=https://pdfs.semanticscholar.org/6b41/4b24c6c33c9e713f114ae1692ada693e2517.pdf |url-status=dead |journal=Geografiska Annaler: Series A, Physical Geography |volume=81A |issue=2 |pages=167–229 |bibcode=1999GeAnA..81..167D |doi=10.1111/j.0435-3676.1999.00057.x |doi-broken-date=18 February 2025 |s2cid=7626031 |archive-url=https://web.archive.org/web/20180212084400/https://pdfs.semanticscholar.org/6b41/4b24c6c33c9e713f114ae1692ada693e2517.pdf |archive-date=2018-02-12}}</ref> and the Otiran in New Zealand.<ref name="Newnham2007">{{cite journal |last1=Newnham |first1=R. M. |last2=Vandergoes |first2=M. J. |last3=Hendy |first3=C. H. |last4=Lowe |first4=D. J. |last5=Preusser |first5=F. |date=February 2007 |title=A terrestrial palynological record for the last two glacial cycles from southwestern New Zealand |journal=[[Quaternary Science Reviews]] |volume=26 |issue=3–4 |pages=517–535 |bibcode=2007QSRv...26..517N |doi=10.1016/j.quascirev.2006.05.005}}</ref>

The Holocene can be subdivided into five time intervals, or [[chronozone]]s, based on climatic fluctuations:<ref>{{Cite journal |title=Quaternary stratigraphy of Norden: a proposal for terminology and classification |date=October 1, 1974 |url=http://folk.uib.no/ngljm/PDF_files/Mangerud%20et%20al%201974,%20Quat%20stratigraphy%20Norden.PDF |journal=[[Boreas (journal)|Boreas]] |last1= Mangerud |first1= Jan |last2= Anderson |first2= Svend T. |last3= Berglund |first3= Bjorn E. |last4=Donner |first4=Joakim J. |volume=3 |issue=3 |pages=109–128 |doi=10.1111/j.1502-3885.1974.tb00669.x |bibcode=1974Borea...3..109M |access-date=September 15, 2013 |archive-date=February 16, 2020 |archive-url= https://web.archive.org/web/20200216182249/https://folk.uib.no/ngljm/PDF_files/Mangerud%20et%20al%201974,%20Quat%20stratigraphy%20Norden.PDF |url-status=live }}</ref>{{Update inline|date=April 2023|?=yes|reason=Does this still hold after so many years? Holocene start date was redefined 35 years after these climatic chronzone dates}}
* [[Preboreal]] (10 ka–9 ka BP),
* [[Boreal (age)|Boreal]] (9 ka–8 ka BP),
* [[Atlantic (period)|Atlantic]] (8 ka–5 ka BP),
* [[Subboreal]] (5 ka–2.5 ka BP) and
* [[Subatlantic]] (2.5 ka BP–present).
: ''Note: "[[year|ka]] BP" means "kilo-annum [[Before Present]]", i.e. 1,000 years before 1950 (non-calibrated [[Radiocarbon dating|C14 dates]])''

Geologists working in different regions are studying sea levels, peat bogs, and [[ice core|ice-core]] samples, using a variety of methods, with a view toward further verifying and refining the [[Blytt-Sernander sequence|Blytt–Sernander sequence]]. This is a classification of climatic periods initially defined by plant remains in [[peat moss]]es.<ref>{{cite journal |last1= Viau |first1= André E. |last2= Gajewski |first2= Konrad |last3= Fines |first3= Philippe |last4= Atkinson |first4= David E. |last5= Sawada |first5= Michael C. |title= Widespread evidence of 1500 yr climate variability in North America during the past 14 000 yr |journal=Geology |date=1 May 2002 |volume=30 |issue= 5 |pages= 455–458 |doi= 10.1130/0091-7613(2002)030<0455:WEOYCV>2.0.CO;2|bibcode= 2002Geo....30..455V }}</ref> Though the method was once thought to be of little interest, based on <sup>14</sup>C dating of peats that was inconsistent with the claimed chronozones,<ref>{{cite encyclopedia |last1=Blackford |first1=J. |title=Peat bogs as sources of proxy climatic data: Past approaches and future research |year=1993 |encyclopedia=Climate change and human impact on the landscape |pages= 47–56 |publisher= Springer |location= Dordrecht |doi= 10.1007/978-94-010-9176-3_5 |isbn= 978-0-412-61860-4 |url= https://link.springer.com/content/pdf/10.1007/978-94-010-9176-3_5.pdf |access-date= 20 November 2020}}</ref> investigators have found a general correspondence across [[Eurasia]] and [[North America]]. The scheme was defined for [[Northern Europe]], but the [[Climate variability and change|climate changes]] were claimed to occur more widely. The periods of the scheme include a few of the final pre-Holocene oscillations of the last glacial period and then classify climates of more recent [[prehistory]].<ref>{{cite journal |last1=Schrøder |first1=N. |last2=Højlund Pedersen |first2=L. |last3=Juel Bitsch |first3= R. |year= 2004 |title= 10,000 years of climate change and human impact on the environment in the area surrounding Lejre |journal=The Journal of Transdisciplinary Environmental Studies |volume=3 |number=1 |pages= 1–27}}</ref>

[[Paleontologists]] have not defined any [[faunal stage]]s for the Holocene. If subdivision is necessary, periods of human technological development, such as the [[Mesolithic]], [[Neolithic]], and [[Bronze Age]], are usually used. However, the time periods referenced by these terms vary with the emergence of those technologies in different parts of the world.<ref>{{Cite web|title=Middle Ages {{!}} Definition, Dates, Characteristics, & Facts |url= https://www.britannica.com/event/Middle-Ages|access-date=2021-06-04|website=Encyclopædia Britannica |language= en|archive-date=2021-06-11|archive-url= https://web.archive.org/web/20210611203625/https://www.britannica.com/event/Middle-Ages|url-status=live}}</ref>

Some scholars have argued that a third epoch of the Quaternary, the [[Anthropocene]], has now begun.<ref>{{cite book |last=Pearce |first=Fred |author-link=Fred Pearce |year= 2007 |title=With Speed and Violence |url= https://archive.org/details/withspeedviolenc00pear |url-access=registration |page=[https://archive.org/details/withspeedviolenc00pear/page/21 21] |publisher= [[Beacon Press]] |isbn= 978-0-8070-8576-9}}</ref> This term has been used to denote the present time-interval in which many geologically significant conditions and processes have been profoundly altered by human activities. The 'Anthropocene' (a term coined by [[Paul J. Crutzen]] and [[Eugene F. Stoermer|Eugene Stoermer]] in 2000) was never a formally defined geological unit. The Subcommission on Quaternary Stratigraphy (SQS) of the [[International Commission on Stratigraphy]] (ICS) had a working group to determine whether it should be. In May 2019, members of the working group voted in favour of recognizing the Anthropocene as formal chrono-stratigraphic unit, with stratigraphic signals around the mid-twentieth century CE as its base. The exact criteria was still to be determined, after which the recommendation also had to be approved by the working group's parent bodies (ultimately the [[International Union of Geological Sciences]]).<ref>{{Cite web|url= http://quaternary.stratigraphy.org/workinggroups/anthropocene/|title=Working Group on the "Anthropocene"|date= January 4, 2016|work=Subcommission on Quaternary Stratigraphy|publisher=[[International Commission on Stratigraphy]] |access-date=June 18, 2017|archive-date=February 17, 2016|archive-url= https://web.archive.org/web/20160217014924/http://quaternary.stratigraphy.org/workinggroups/anthropocene/|url-status=live}}
</ref> In March 2024, after 15 years of deliberation, the Anthropocene Epoch proposal of the working group was voted down by a wide margin by the SQS, owing largely to its shallow sedimentary record and extremely recent proposed start date.<ref name="Zhong-2024a">{{Cite news |last=Zhong |first=Raymond |date=2024-03-05 |title=Are We in the 'Anthropocene,' the Human Age? Nope, Scientists Say. |url=https://www.nytimes.com/2024/03/05/climate/anthropocene-epoch-vote-rejected.html |access-date=2024-03-05 |work=The New York Times |language=en-US |issn=0362-4331}}</ref><ref name="Zhong-2024b">{{Cite news |last=Zhong |first=Raymond |date=2024-03-20 |title=Geologists Make It Official: We're Not in an 'Anthropocene' Epoch |url=https://www.nytimes.com/2024/03/20/climate/anthropocene-vote-upheld.html |access-date=2024-04-19 |work=The New York Times |language=en-US |issn=0362-4331}}</ref> The ICS and the International Union of Geological Sciences later formally confirmed, by a near unanimous vote, the rejection of the working group's Anthropocene Epoch proposal for inclusion in the Geologic Time Scale.<ref name="International Chronostratigraphic Chart">{{cite web |title=International Chronostratigraphic Chart |url=https://stratigraphy.org/chart |access-date=7 April 2024 |publisher=[[International Commission on Stratigraphy]]}}</ref><ref name="quaternary.stratigraphy.org">{{cite web |title=What is the Anthropocene? – current definition and status |url=http://quaternary.stratigraphy.org/working-groups/anthropocene/ |access-date=7 April 2024 |website=quaternary.stratigraphy.org |publisher=Subcommission on Quaternary Stratigraphy, Working Group on the 'Anthropocene'}}</ref><ref name="The Anthropocene">The Anthropocene: IUGS-ICS Statement. March 20, 2024. https://www.iugs.org/_files/ugd/f1fc07_ebe2e2b94c35491c8efe570cd2c5a1bf.pdf</ref>