Editing Holocene extinction (section)

==== Agriculture and climate change ====
[[File:Operação Hymenaea, Julho-2016 (29399454651).jpg|thumb|[[Deforestation of the Amazon rainforest|Deforestation]] in the [[Maranhão]] state, Brazil, in July 2016]]
Recent investigations into the practice of landscape burning during the [[Neolithic Revolution]] have a major implication for the current debate about the timing of the Anthropocene and the role that humans may have played in the production of greenhouse gases prior to the [[Industrial Revolution]].<ref name="Ruddiman-2009" /> Studies of early hunter-gatherers raise questions about the current use of population size or density as a [[Proxy (climate)|proxy]] for the amount of land clearance and anthropogenic burning that took place in pre-industrial times.<ref name="Lynch-2011">{{Cite web|url=https://climate.nasa.gov/news/649/|title=Secrets from the past point to rapid climate change in the future|last=Lynch|first=Patrick|date=15 December 2011|publisher=NASA's Earth Science News Team|access-date=2 April 2016|archive-date=29 June 2016|archive-url=https://web.archive.org/web/20160629173812/https://climate.nasa.gov/news/649/|url-status=live}}</ref><ref name="Ruddiman-2013">{{Cite journal|last=Ruddiman|first=W.F.|date=2013|title=The Anthropocene|journal=Annual Review of Earth and Planetary Sciences|volume=41|pages=45–68|doi=10.1146/annurev-earth-050212-123944|bibcode=2013AREPS..41...45R}}</ref> Scientists have questioned the correlation between population size and early territorial alterations.<ref name="Ruddiman-2013" /> Ruddiman and Ellis' research paper in 2009 makes the case that early farmers involved in systems of agriculture used more land per capita than growers later in the Holocene, who intensified their labor to produce more food per unit of area (thus, per laborer); arguing that agricultural involvement in rice production implemented thousands of years ago by relatively small populations created significant environmental impacts through large-scale means of deforestation.<ref name="Ruddiman-2009" />

While a number of human-derived factors are recognized as contributing to rising atmospheric concentrations of CH<sub>4</sub> (methane) and CO<sub>2</sub> (carbon dioxide), deforestation and territorial clearance practices associated with agricultural development may have contributed most to these concentrations globally in earlier millennia.<ref name="Cruzten-2002" /><ref name="Ruddiman-2009" /><ref name="Tollefson-2011" /> Scientists that are employing a variance of [[Archaeology|archaeological]] and paleoecological data argue that the processes contributing to substantial human modification of the environment spanned many thousands of years on a global scale and thus, not originating as late as the [[Industrial Revolution]]. Palaeoclimatologist [[William Ruddiman]] has argued that in the early Holocene 11,000 years ago, atmospheric carbon dioxide and methane levels fluctuated in a pattern which was different from the Pleistocene epoch before it.<ref name="Ruddiman-2003"/><ref name="Lynch-2011" /><ref name="Tollefson-2011">{{Cite journal|last=Tollefson|first=Jeff|date=2011-03-25|title=The 8,000-year-old climate puzzle|url=http://www.nature.com/news/2011/110325/full/news.2011.184.html|journal=Nature News|doi=10.1038/news.2011.184|doi-access=free|access-date=2016-04-08|archive-date=2021-03-08|archive-url=https://web.archive.org/web/20210308145040/https://www.nature.com/news/2011/110325/full/news.2011.184.html|url-status=live}}</ref> He argued that the patterns of the significant decline of CO<sub>2</sub> levels during the last ice age of the Pleistocene inversely correlate to the Holocene where there have been dramatic increases of CO<sub>2</sub> around 8000 years ago and CH<sub>4</sub> levels 3000 years after that.<ref name="Tollefson-2011" /> The correlation between the decrease of CO<sub>2</sub> in the Pleistocene and the increase of it during the [[Holocene]] implies that the causation of this spark of greenhouse gases into the atmosphere was the growth of [[Agriculture|human agriculture]] during the Holocene.<ref name="Ruddiman-2003"/><ref name="Tollefson-2011" />