Editing Fertilizer (section)

===Atmosphere===
[[File:AtmosphericMethane.png|thumb|Global [[methane]] concentrations (surface and atmospheric) for 2005; note distinct plumes]]
Through the increasing use of nitrogen fertilizer, which was used at a rate of about 110 million tons (of N) per year in 2012,<ref name=FAO2012>{{cite book|last1=FAO|title=Current world fertilizer trends and outlook to 2016|date=2012|publisher=Food and Agriculture Organization of the United Nations|location=Rome|page=13|url=ftp://ftp.fao.org/ag/agp/docs/cwfto16.pdf|archive-url=https://web.archive.org/web/20170518105637/ftp://ftp.fao.org/ag/agp/docs/cwfto16.pdf|url-status=dead|archive-date=2017-05-18|access-date=3 July 2014}}</ref><ref>{{cite journal |doi=10.1038/nature06592|bibcode = 2008Natur.451..293G | volume=451 |issue = 7176 | title=An Earth-system perspective of the global nitrogen cycle |journal=Nature |pages=293–296 |pmid=18202647 | last1 = Gruber | first1 = N | last2 = Galloway | first2 = JN|year = 2008 |doi-access = free }}</ref> adding to the already existing amount of reactive nitrogen, [[nitrous oxide]] (N<sub>2</sub>O) has become the third most important [[greenhouse gas]] after carbon dioxide and methane. It has a [[global warming potential]] 296 times larger than an equal mass of carbon dioxide and it also contributes to stratospheric ozone depletion.<ref>[http://www.initrogen.org/fileadmin/user_upload/2007_docs/2007-N-joint-policy-brief.pdf "Human alteration of the nitrogen cycle, threats, benefits and opportunities"] {{webarchive|url=https://web.archive.org/web/20090114121452/http://initrogen.org/fileadmin/user_upload/2007_docs/2007-N-joint-policy-brief.pdf |archive-url=https://ghostarchive.org/archive/20221009/http://initrogen.org/fileadmin/user_upload/2007_docs/2007-N-joint-policy-brief.pdf |archive-date=2022-10-09 |url-status=live |date=14 January 2009 }} [[UNESCO]]&nbsp;– [[Scientific Committee on Problems of the Environment|SCOPE]] Policy briefs, April 2007</ref>
By changing processes and procedures, it is possible to mitigate some, but not all, of these effects on anthropogenic [[climate change]].<ref name=Roy2002>{{cite journal|last1=Roy|first1=R. N.|last2=Misra|first2=R. V.|last3=Montanez|first3=A.|title=Decreasing reliance on mineral nitrogen-yet more food|journal=Ambio: A Journal of the Human Environment|date=2002|volume=31|issue=2|pages=177–183|doi=10.1579/0044-7447-31.2.177|pmid=12078007|bibcode=2002Ambio..31..177R |s2cid=905322|url=http://www.planta.cn/forum/files_planta/decreasing_reliance_on_mineral_nitrogenyet_more_food_364.pdf|access-date=3 July 2014|url-status=dead|archive-url=https://web.archive.org/web/20150924074035/http://www.planta.cn/forum/files_planta/decreasing_reliance_on_mineral_nitrogenyet_more_food_364.pdf|archive-date=24 September 2015}}</ref>

[[Methane emissions]] from crop fields (notably rice [[paddy field]]s) are increased by the application of ammonium-based fertilizers. These emissions contribute to global climate change as methane is a potent greenhouse gas.<ref name="Stimulation by ammonium-based fertilizers of methane oxidation in soil around rice roots">{{cite journal|last1=Bodelier|first1=Paul|author2=Peter Roslev|author3=Thilo Henckel|author4=Peter Frenzel|date=November 1999|title=Stimulation by ammonium-based fertilizers of methane oxidation in soil around rice roots |journal=Nature|volume=403|pages=421–424 |pmid=10667792|issue=6768|doi=10.1038/35000193 |bibcode=2000Natur.403..421B|s2cid=4351801}}</ref><ref name=Banger2012>{{cite journal|last1=Banger|first1=K.|last2=Tian|first2=H.|last3=Lu|first3=C.|title=Do nitrogen fertilizers stimulate or inhibit methane emissions from rice fields?|journal=Global Change Biology|date=2012|volume=18|issue=10|pages=3259–3267|doi=10.1111/j.1365-2486.2012.02762.x|pmid=28741830|bibcode=2012GCBio..18.3259B|s2cid=31666406 }}</ref>