Editing Holocene extinction (section)

=== Scientific debate ===
[[File:Human population since 1800.png|alt=|thumb|World [[World population|human population]] since 1800 in billions. Data from the [https://population.un.org/wpp/ United Nations projections in 2019].]]
The description of recent extinction as a mass extinction has been debated among scientists. [[Stuart Pimm]], for example, asserts that the sixth mass extinction "is something that hasn't happened yet—we are on the edge of it."<ref name="Carrington">{{cite news |last=Carrington |first=Damian |date=10 July 2017 |title=Earth's sixth mass extinction event under way, scientists warn |work=The Guardian |url=https://www.theguardian.com/environment/2017/jul/10/earths-sixth-mass-extinction-event-already-underway-scientists-warn |access-date=November 4, 2017 |archive-date=2 January 2020 |archive-url=https://web.archive.org/web/20200102063436/https://www.theguardian.com/environment/2017/jul/10/earths-sixth-mass-extinction-event-already-underway-scientists-warn |url-status=live }}</ref> Several studies posit that the Earth has entered a sixth mass extinction event,<ref name="dirzo" /><ref name="Wake2008" /><ref name="Ceballos-Ehrlich-2017-05" /><ref name="Ceballos2020" /> including a 2015 paper by Barnosky et al.<ref name=ceballos/> and a November 2017 statement titled "[[World Scientists' Warning to Humanity#Second notice|World Scientists' Warning to Humanity: A Second Notice]]", led by eight authors and signed by 15,364 scientists from 184 countries which asserted, among other things, that "we have unleashed a mass extinction event, the sixth in roughly 540 million years, wherein many current life forms could be extirpated or at least committed to extinction by the end of this century."<ref name="WorldScientists">{{cite journal|vauthors=Ripple WJ, Wolf C, Newsome TM, Galetti M, Alamgir M, Crist E, Mahmoud MI, Laurance WF|title=World Scientists' Warning to Humanity: A Second Notice|journal=[[BioScience]] |volume=67|issue=12|pages=1026–1028|date=13 November 2017|doi=10.1093/biosci/bix125 |url=http://scientistswarning.forestry.oregonstate.edu/sites/sw/files/Warning_article_with_supp_11-13-17.pdf|quote=Moreover, we have unleashed a mass extinction event, the sixth in roughly 540 million years, wherein many current life forms could be annihilated or at least committed to extinction by the end of this century.|access-date=12 July 2018|url-status=dead|archive-date=15 December 2019|archive-url=https://web.archive.org/web/20191215010626/https://scientistswarning.forestry.oregonstate.edu/sites/sw/files/Warning_article_with_supp_11-13-17.pdf}}</ref> The [[World Wide Fund for Nature]]'s 2020 ''[[Living Planet Report]]'' says that [[wildlife]] populations have declined by 68% since 1970 as a result of [[overconsumption]], [[population growth]], and [[intensive farming]], which is further evidence that humans have unleashed a sixth mass extinction event; however, this finding has been disputed by one 2020 study, which posits that this major decline was primarily driven by a few extreme outlier populations, and that when these outliers are removed, the trend shifts to that of a decline between the 1980s and 2000s, but a roughly positive trend after 2000.<ref>{{cite news|last=Greenfield|first=Patrick|date=September 9, 2020|title=Humans exploiting and destroying nature on unprecedented scale – report|url=https://www.theguardian.com/environment/2020/sep/10/humans-exploiting-and-destroying-nature-on-unprecedented-scale-report-aoe|work=The Guardian|access-date=September 10, 2020|archive-date=October 21, 2021|archive-url=https://web.archive.org/web/20211021225045/https://www.theguardian.com/environment/2020/sep/10/humans-exploiting-and-destroying-nature-on-unprecedented-scale-report-aoe|url-status=live}}</ref><ref>{{cite news|last=Briggs|first=Helen|date=September 10, 2020|title=Wildlife in 'catastrophic decline' due to human destruction, scientists warn|url=https://www.bbc.com/news/science-environment-54091048|work=BBC|access-date=September 10, 2020|archive-date=January 10, 2021|archive-url=https://web.archive.org/web/20210110233814/https://www.bbc.com/news/science-environment-54091048|url-status=live}}</ref><ref name="Lewis2020">{{cite news|last=Lewis|first=Sophie|date=September 9, 2020|title=Animal populations worldwide have declined by almost 70% in just 50 years, new report says|url=https://www.cbsnews.com/news/biodiversity-endangered-species-animal-population-decline-world-wildlife-fund-report-2020-09-09/|work=[[CBS News]]|access-date=October 22, 2020|archive-date=September 10, 2020|archive-url=https://web.archive.org/web/20200910152119/https://www.cbsnews.com/news/biodiversity-endangered-species-animal-population-decline-world-wildlife-fund-report-2020-09-09/|url-status=live}}</ref><ref>{{Cite journal|last1=Leung|first1=Brian|last2=Hargreaves|first2=Anna L.|last3=Greenberg|first3=Dan A.|last4=McGill|first4=Brian|last5=Dornelas|first5=Maria|last6=Freeman|first6=Robin|date=December 2020|title=Clustered versus catastrophic global vertebrate declines|journal=Nature|volume=588|issue=7837|pages=267–271|doi=10.1038/s41586-020-2920-6|pmid=33208939|bibcode=2020Natur.588..267L|hdl=10023/23213|s2cid=227065128|issn=1476-4687|url=https://discovery.ucl.ac.uk/id/eprint/10116420/3/Freeman_Leung_et_al_Vertebrate_Declines_final3e.pdf|hdl-access=free|access-date=2024-04-26|archive-date=2023-12-03|archive-url=https://web.archive.org/web/20231203132327/https://discovery.ucl.ac.uk/id/eprint/10116420/3/Freeman_Leung_et_al_Vertebrate_Declines_final3e.pdf|url-status=live}}</ref> A 2021 report in ''Frontiers in Conservation Science'' which cites both of the aforementioned studies, says "population sizes of vertebrate species that have been monitored across years have declined by an average of 68% over the last five decades, with certain population clusters in extreme decline, thus presaging the imminent extinction of their species," and asserts "that we are already on the path of a sixth major extinction is now scientifically undeniable."<ref name="Bradshaw2021">{{cite journal|last1=Bradshaw |first1=Corey J. A.|last2=Ehrlich|first2=Paul R. |last3=Beattie|first3=Andrew |last4=Ceballos |first4=Gerardo|last5=Crist|first5=Eileen|last6=Diamond|first6=Joan|last7=Dirzo|first7=Rodolfo |last8=Ehrlich|first8=Anne H.|last9=Harte|first9=John|last10=Harte|first10=Mary Ellen|last11=Pyke |first11=Graham |last12=Raven|first12=Peter H.|last13=Ripple|first13=William J.|last14=Saltré |first14=Frédérik|last15=Turnbull|first15=Christine|last16=Wackernagel|first16=Mathis|last17=Blumstein |first17=Daniel T.|date=2021 |title=Underestimating the Challenges of Avoiding a Ghastly Future |journal=Frontiers in Conservation Science|volume=1|issue=|pages=|doi=10.3389/fcosc.2020.615419|doi-access=free|bibcode=2021FrCS....1.5419B }}</ref> A January 2022 [[review article]] published in ''Biological Reviews'' builds upon previous studies documenting biodiversity decline to assert that a sixth mass extinction event caused by anthropogenic activity is currently under way.<ref name="Cowie">{{cite journal |last1=Cowie |first1=Robert H. |last2=Bouchet |first2=Philippe |last3=Fontaine |first3=Benoît |date=2022 |title=The Sixth Mass Extinction: fact, fiction or speculation? |journal=Biological Reviews |volume=97 |issue=2 |pages=640–663 |doi=10.1111/brv.12816 |pmid=35014169 |pmc=9786292 |quote=Our review lays out arguments clearly demonstrating that there is a biodiversity crisis, quite probably the start of the Sixth Mass Extinction. |s2cid=245889833}}</ref><ref>{{cite news|last=Sankaran|first=Vishwam|date=January 17, 2022|title=Study confirms sixth mass extinction is currently underway, caused by humans|work=[[The Independent]]|url=https://www.independent.co.uk/climate-change/news/sixth-mass-extinction-global-biodiversity-b1994346.html|access-date=January 17, 2022|archive-date=January 17, 2022|archive-url=https://web.archive.org/web/20220117205431/https://www.independent.co.uk/climate-change/news/sixth-mass-extinction-global-biodiversity-b1994346.html|url-status=live}}</ref> A December 2022 study published in ''[[Science Advances]]'' states that "the planet has entered the sixth mass extinction" and warns that current anthropogenic trends, particularly regarding climate and [[land-use change]]s, could result in the loss of more than a tenth of plant and animal species by the end of the century.<ref>{{cite journal |last1=Strona |first1= Giovanni |last2=Bradshaw |first2=Corey J. A. |date=16 December 2022 |title=Coextinctions dominate future vertebrate losses from climate and land use change|url= |journal=Science Advances|volume=8 |issue=50 |pages= eabn4345|doi=10.1126/sciadv.abn4345|pmid= 36525487 |pmc= 9757742 |bibcode= 2022SciA....8N4345S |s2cid= 254803380 |access-date=}}</ref><ref>{{cite news |last=Greenfield |first=Patrick |date=16 December 2022 |title=More than 1 in 10 species could be lost by end of century, study warns|url=https://www.theguardian.com/environment/2022/dec/16/more-than-1-in-10-species-could-be-lost-by-end-of-century-study-warns-aoe|work=The Guardian |location= |access-date=18 December 2022}}</ref> 12% of all bird species are threatened with extinction.<ref>{{Cite journal |last1=Pimm |first1=Stuart |last2=Raven |first2=Peter |last3=Peterson |first3=Alan |last4=Şekercioğlu |first4=Çağan H. |last5=Ehrlich |first5=Paul R. |date=18 July 2006 |title=Human impacts on the rates of recent, present, and future bird extinctions |journal=[[Proceedings of the National Academy of Sciences of the United States of America]] |language=en |volume=103 |issue=29 |pages=10941–10946 |doi=10.1073/pnas.0604181103 |doi-access=free |issn=0027-8424 |pmc=1544153 |pmid=16829570 }}</ref> A 2023 study published in ''Biological Reviews'' found that, of 70,000 monitored species, some 48% are experiencing population declines from anthropogenic pressures, whereas only 3% have increasing populations.<ref>{{cite news |author=<!--not stated--> |date=May 23, 2023 |title=Biodiversity: Almost half of animals in decline, research shows |url=https://www.bbc.com/news/uk-northern-ireland-65681648 |work=BBC |location= |access-date=May 23, 2023 |archive-date=July 17, 2023 |archive-url=https://web.archive.org/web/20230717222234/https://www.bbc.com/news/uk-northern-ireland-65681648 |url-status=live }}</ref><ref>{{cite journal |last1=Finn|first1=Catherine|last2=Grattarola|first2=Florencia |last3=Pincheira-Donoso|first3=Daniel |date=2023 |title=More losers than winners: investigating Anthropocene defaunation through the diversity of population trends|url= |journal=Biological Reviews|volume= 98|issue= 5|pages= 1732–1748|doi=10.1111/brv.12974|pmid=37189305 |s2cid=258717720 |access-date=}}</ref><ref>{{cite news|last=Paddison|first=Laura|date=May 22, 2023|title=Global loss of wildlife is 'significantly more alarming' than previously thought, according to a new study|url=https://www.cnn.com/2023/05/22/world/wildlife-crisis-biodiversity-scn-climate-intl/index.html|work=CNN|location=|access-date=May 23, 2023|archive-date=May 25, 2023|archive-url=https://web.archive.org/web/20230525012839/https://www.cnn.com/2023/05/22/world/wildlife-crisis-biodiversity-scn-climate-intl/index.html|url-status=live}}</ref>

According to the [[UNDP]]'s 2020 [[Human Development Report]], ''The Next Frontier: Human Development and the Anthropocene'':

{{blockquote|text=The planet's biodiversity is plunging, with a quarter of species facing extinction, many within decades. Numerous experts believe we are living through, or on the cusp of, a mass species extinction event, the sixth in the history of the planet and the first to be caused by a single organism—us.<ref>{{cite web|url=http://hdr.undp.org/sites/default/files/hdr_2020_overview_english.pdf|title=The Next Frontier: Human Development and the Anthropocene|date=December 15, 2020|page=3|publisher=UNDP|access-date=December 16, 2020|archive-date=December 16, 2020|archive-url=https://web.archive.org/web/20201216001954/http://hdr.undp.org/sites/default/files/hdr_2020_overview_english.pdf|url-status=live}}</ref>}}

The 2022 ''Living Planet Report'' found that vertebrate wildlife populations have plummeted by an average of almost 70% since 1970, with agriculture and fishing being the primary drivers of this decline.<ref>{{cite news |last=Greenfield|first=Patrick |date=October 12, 2022 |title=Animal populations experience average decline of almost 70% since 1970, report reveals |url=https://www.theguardian.com/environment/2022/oct/13/almost-70-of-animal-populations-wiped-out-since-1970-report-reveals-aoe|work=The Guardian |access-date=October 15, 2022}}</ref><ref>{{cite news|last=Einhorn|first=Catrin|date=October 12, 2022|title=Researchers Report a Staggering Decline in Wildlife. Here's How to Understand It.|url=https://www.nytimes.com/2022/10/12/climate/living-planet-index-wildlife-declines.html|work=The New York Times|location=|access-date=October 15, 2022|archive-date=October 14, 2022|archive-url=https://web.archive.org/web/20221014202709/https://www.nytimes.com/2022/10/12/climate/living-planet-index-wildlife-declines.html|url-status=live}}</ref>

Some scientists, including [[Rodolfo Dirzo]] and [[Paul R. Ehrlich]], contend that the sixth mass extinction is largely unknown to most people globally and is also misunderstood by many in the scientific community. They say it is not the disappearance of species, which gets the most attention, that is at the heart of the crisis, but "the existential threat of myriad population extinctions."<ref name="Dirzo2022">{{cite journal |last1=Dirzo |first1=Rodolfo|last2=Ceballos|first2=Gerardo|last3=Ehrlich |first3=Paul R. |date=2022 |title=Circling the drain: the extinction crisis and the future of humanity |journal=[[Philosophical Transactions of the Royal Society B]] |volume=377|issue=1857 |pages= |doi=10.1098/rstb.2021.0378|pmid=35757873 |pmc=9237743}}</ref>