Editing Fire (section)

=== Fossil record ===
{{Main|Fossil record of fire}}
The fossil record of fire first appears with the establishment of a land-based flora in the [[Middle Ordovician]] period, {{ma|470}}.<ref name="Wellman2000">{{cite journal |last1=Wellman |first1=C. H. |last2=Gray |first2=J. |year=2000 |title=The microfossil record of early land plants |journal=Philos Trans R Soc Lond B Biol Sci |volume=355 |issue=1398 |pages=717–31; discussion 731–2 |doi=10.1098/rstb.2000.0612 |pmc=1692785 |pmid=10905606}}</ref> These land plants contributed large amounts of [[oxygen]] to the atmosphere when they released it as a waste product. When this concentration rose above 13%, it permitted the possibility of [[wildfire]].<ref name="Jones1991">{{cite journal |last1=Jones |first1=Timothy P. |last2=Chaloner |first2=William G. |year=1991 |title=Fossil charcoal, its recognition and palaeoatmospheric significance |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=97 |issue=1–2 |pages=39–50 |bibcode=1991PPP....97...39J |doi=10.1016/0031-0182(91)90180-Y}}</ref> Wildfire is first recorded in the [[Late Silurian]] fossil record, {{Ma|420}}, by fossils of [[charcoal|charred]] plants.<ref name="DoiGMissing">{{cite journal |last1=Glasspool |first1=I. J. |last2=Edwards |first2=D. |last3=Axe |first3=L. |year=2004 |title=Charcoal in the Silurian as evidence for the earliest wildfire |journal=Geology |volume=32 |issue=5 |pages=381–383 |bibcode=2004Geo....32..381G |doi=10.1130/G20363.1}}</ref><ref name="Scott2006">{{cite journal |last1=Scott |first1=A. C. |last2=Glasspool |first2=I. J. |year=2006 |title=The diversification of Paleozoic fire systems and fluctuations in atmospheric oxygen concentration |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=103 |issue=29 |pages=10861–5 |bibcode=2006PNAS..10310861S |doi=10.1073/pnas.0604090103 |pmc=1544139 |pmid=16832054 |doi-access=free}}</ref> Apart from a controversial gap in the [[Late Devonian]], charcoal is present ever since.<ref name="Scott2006" /> The level of atmospheric oxygen is closely correlated with the amount of charcoal in the fossil record, clearly pointing to oxygen as the key factor in the prevalence of wildfire.<ref name="Bowman2009">{{cite journal |last1=Bowman |first1=D. M. J. S. |last2=Balch |first2=J. K. |last3=Artaxo |first3=P. |last4=Bond |first4=W. J. |last5=Carlson |first5=J. M. |last6=Cochrane |first6=M. A. |last7=d'Antonio |first7=C. M. |last8=Defries |first8=R. S. |last9=Doyle |first9=J. C. |last10=Harrison |first10=S. P. |last11=Johnston |first11=F. H. |last12=Keeley |first12=J. E. |last13=Krawchuk |first13=M. A. |last14=Kull |first14=C. A. |last15=Marston |first15=J. B. |year=2009 |title=Fire in the Earth system |journal=Science |volume=324 |issue=5926 |pages=481–4 |bibcode=2009Sci...324..481B |doi=10.1126/science.1163886 |pmid=19390038 |s2cid=22389421 |last16=Moritz |first16=M. A. |last17=Prentice |first17=I. C. |last18=Roos |first18=C. I. |last19=Scott |first19=A. C. |last20=Swetnam |first20=T. W. |last21=Van Der Werf |first21=G. R. |last22=Pyne |first22=S. J. |url=https://resolver.caltech.edu/CaltechAUTHORS:20090707-150808418 |access-date=2024-01-26 |archive-date=2024-05-27 |archive-url=https://web.archive.org/web/20240527111415/https://authors.library.caltech.edu/records/m358a-0c317 |url-status=live }}</ref> Fire also became more abundant when grasses became the dominant component of many ecosystems, around {{Ma|6|7}},<ref name="Retallack1997">{{cite journal |last1=Retallack |first1=Gregory J. |date=1997 |title=Neogene expansion of the North American prairie |journal=PALAIOS |volume=12 |issue=4 |pages=380–90 |bibcode=1997Palai..12..380R |doi=10.2307/3515337 |jstor=3515337}}</ref> providing excellent [[tinder]] for more rapid spread of fire.<ref name="Bowman2009" /> This widespread emergence of wildfire may have initiated a [[positive feedback]] process, whereby they produced a warmer, drier climate more conducive to fire.<ref name="Bowman2009" />