Editing Agriculture (section)

== Environmental impact ==
{{Main|Environmental issues with agriculture}}

=== Effects and costs ===
[[File:Water pollution in the Wairarapa.JPG|upright|thumb|[[Water pollution]] in a rural stream due to [[Agricultural pollution in New Zealand|runoff from farming activity in New Zealand]]]]

Agriculture is both a cause of and sensitive to [[environmental degradation]], such as [[biodiversity loss]], [[desertification]], [[soil degradation]] and [[Effects of climate change on agriculture|climate change]], which cause decreases in crop yield.<ref>{{cite web |title=Making Peace with Nature: A scientific blueprint to tackle the climate, biodiversity and pollution emergencies |year=2021 |publisher=United Nations Environment Programme |url=https://www.unep.org/resources/making-peace-nature |access-date=9 June 2021 |archive-date=23 March 2021 |archive-url=https://web.archive.org/web/20210323211102/https://www.unep.org/resources/making-peace-nature |url-status=live}}</ref> Agriculture is one of the most important drivers of environmental pressures, particularly habitat change, climate change, water use and toxic emissions. Agriculture is the main source of toxins released into the environment, including [[insecticide]]s, especially those used on cotton.<ref>{{cite web |author=International Resource Panel |year=2010 |title=Priority products and materials: assessing the environmental impacts of consumption and production |url=http://www.unep.org/resourcepanel/Publications/PriorityProducts/tabid/56053/Default.aspx |url-status=dead |archive-url=https://web.archive.org/web/20121224061455/http://www.unep.org/resourcepanel/Publications/PriorityProducts/tabid/56053/Default.aspx |archive-date=24 December 2012 |access-date=7 May 2013 |publisher=United Nations Environment Programme |pages=13 & 40}}</ref><ref>{{cite book |last1=Frouz |first1=Jan |url=https://link.springer.com/book/10.1007/978-3-030-83225-4 |title=Applied Ecology: How agriculture, forestry and fisheries shape our planet |last2=Frouzová |first2=Jaroslava |date=2022 |isbn=978-3-030-83224-7 |pages=116 & 165 |doi=10.1007/978-3-030-83225-4 |access-date=19 December 2021 |archive-url=https://web.archive.org/web/20220129031136/https://link.springer.com/book/10.1007/978-3-030-83225-4 |archive-date=29 January 2022 |url-status=live |s2cid=245009867}}</ref> The 2011 UNEP Green Economy report stated that agricultural operations produced some 13 percent of anthropogenic global greenhouse gas emissions. This includes gases from the use of inorganic fertilizers, agro-chemical pesticides, and herbicides, as well as fossil fuel-energy inputs.<ref name="unep.org">{{cite web |title=Towards a Green Economy: Pathways to Sustainable Development and Poverty Eradication |publisher=UNEP |year=2011 |url=https://www.unenvironment.org/search/node?keys=Towards+a+Green+Economy%3A+Pathways+to+Sustainable+Development+and+Poverty+Eradication |access-date=9 June 2021 |archive-date=10 May 2020 |archive-url=https://web.archive.org/web/20200510022300/https://www.unenvironment.org/search/node?keys=Towards+a+Green+Economy:+Pathways+to+Sustainable+Development+and+Poverty+Eradication |url-status=live}}</ref>

Agriculture imposes multiple external costs upon society through effects such as pesticide damage to nature (especially herbicides and insecticides), nutrient runoff, excessive water usage, and loss of natural environment. A 2000 assessment of agriculture in the UK determined total external costs for 1996 of £2,343&nbsp;million, or £208 per hectare.<ref name=Pretty2000>{{cite journal |last1=Pretty |year=2000 |title=An assessment of the total external costs of UK agriculture |journal=Agricultural Systems |volume=65 |issue=2 |pages=113–136 |doi=10.1016/S0308-521X(00)00031-7 |first1=J. |display-authors=1 |last2=Brett |first2=C. |last3=Gee |first3=D. |last4=Hine |first4=R. E. |last5=Mason |first5=C. F. |last6=Morison |first6=J. I. L. |last7=Raven |first7=H. |last8=Rayment |first8=M. D. |last9=Van Der Bijl |first9=G. |url=https://www.researchgate.net/publication/222549141 |url-status=live |archive-url=https://web.archive.org/web/20170113233847/https://www.researchgate.net/publication/222549141 |archive-date=13 January 2017 |doi-access=free |bibcode=2000AgSys..65..113P}}</ref> A 2005 analysis of these costs in the US concluded that cropland imposes approximately $5 to $16&nbsp;billion ($30 to $96 per hectare), while livestock production imposes $714&nbsp;million.<ref name=Tegtmeier2005>{{cite journal |last1=Tegtmeier |first1=E. M. |last2=Duffy |first2=M. |year=2005 |title=External Costs of Agricultural Production in the United States |journal=The Earthscan Reader in Sustainable Agriculture |url=http://www.organicvalley.coop/fileadmin/pdf/ag_costs_IJAS2004.pdf |url-status=live |archive-url=https://web.archive.org/web/20090205134016/http://www.organicvalley.coop/fileadmin/pdf/ag_costs_IJAS2004.pdf |archive-date=5 February 2009}}</ref> Both studies, which focused solely on the fiscal impacts, concluded that more should be done to internalize external costs. Neither included subsidies in their analysis, but they noted that subsidies also influence the cost of agriculture to society.<ref name=Pretty2000 /><ref name=Tegtmeier2005 />

Agriculture seeks to increase yield and to reduce costs, often employing measures that cut biodiversity to very low levels. Yield increases with inputs such as fertilizers and removal of pathogens, predators, and competitors (such as weeds). Costs decrease with increasing scale of farm units, such as making fields larger; this means removing [[hedge]]s, ditches and other areas of habitat. Pesticides kill insects, plants and fungi. Effective yields fall with on-farm losses, which may be caused by poor production practices during harvesting, handling, and storage.<ref>{{Cite book |url=http://www.fao.org/documents/card/en/c/ca6122en |title=The State of Food and Agriculture 2019. Moving forward on food loss and waste reduction, In brief |publisher=[[Food and Agriculture Organization]] |year=2019 |page=12 |access-date=4 May 2021 |archive-date=29 April 2021 |archive-url=https://web.archive.org/web/20210429155350/http://www.fao.org/documents/card/en/c/ca6122en |url-status=live}}</ref>

The environmental effects of climate change show that research on pests and diseases that do not generally afflict areas is essential. In 2021, farmers discovered [[stem rust]] on wheat in the [[Champagne (province)|Champagne]] area of France, a disease that had previously only occurred in [[Morocco]] for 20 to 30 years. Because of climate change, insects that used to die off over the winter are now alive and multiplying.<ref>{{Cite web |title=French firm breeds plants that resist climate change |url=https://www.eib.org/en/stories/breeding-plants-climate-change |access-date=25 January 2023 |website=European Investment Bank |archive-date=2 February 2023 |archive-url=https://web.archive.org/web/20230202152944/https://www.eib.org/en/stories/breeding-plants-climate-change |url-status=live}}</ref><ref>{{Cite news |date=3 February 2017 |title=New virulent disease threatens wheat crops in Europe and North Africa – researchers |work=Reuters |url=https://www.reuters.com/article/mediterranean-food-infection-idAFL5N1FO2GJ |access-date=25 January 2023 |archive-date=25 January 2023 |archive-url=https://web.archive.org/web/20230125152806/https://www.reuters.com/article/mediterranean-food-infection-idAFL5N1FO2GJ |url-status=live}}</ref>

=== Livestock issues ===
[[File:Biogas.jpg|thumb|Farmyard [[anaerobic digester]] converts waste plant material and manure from livestock into [[biogas]] fuel.]]

A senior UN official, Henning Steinfeld, said that "Livestock are one of the most significant contributors to today's most serious environmental problems".<ref>{{cite web |url=http://www.fao.org/newsroom/en/news/2006/1000448/index.html |title=Livestock a major threat to environment |publisher=UN Food and Agriculture Organization |date=29 November 2006 |access-date=24 April 2013 |archive-url=https://web.archive.org/web/20080328062709/http://www.fao.org/newsroom/en/news/2006/1000448/index.html |archive-date=28 March 2008 |url-status=live}}</ref> Livestock production occupies 70% of all land used for agriculture, or 30% of the land surface of the planet. It is one of the largest sources of [[greenhouse gas]]es, responsible for 18% of the world's [[greenhouse gas emissions]] as measured in CO<sub>2</sub> equivalents. By comparison, all transportation emits 13.5% of the CO<sub>2</sub>. (This comparison later turned out to be an apples-and-oranges analogy<ref>{{Cite news |date=2010-03-24 |title=UN to look at climate meat link |url=http://news.bbc.co.uk/2/hi/8583308.stm |access-date=2025-04-21 |language=en-GB}}</ref>.) It produces 65% of human-related [[nitrous oxide]] (which has 296 times the [[global warming potential]] of CO<sub>2</sub>) and 37% of all human-induced [[methane]] (which is 23 times as warming as CO<sub>2</sub>.) It also generates 64% of the [[ammonia]] emission. Livestock expansion is cited as a key factor driving [[deforestation]]; in the Amazon basin 70% of [[Deforestation of the Amazon Rainforest|previously forested area]] is now occupied by pastures and the remainder used for feed crops.<ref name="LEAD">{{cite web |archive-url=https://web.archive.org/web/20080625012113/http://www.virtualcentre.org/en/library/key_pub/longshad/A0701E00.pdf |archive-date=25 June 2008 |last1=Steinfeld |first1=H. |last2=Gerber |first2=P. |last3=Wassenaar |first3=T. |last4=Castel |first4=V. |last5=Rosales |first5=M. |last6=de Haan |first6=C. |year=2006 |publisher=U.N. Food and Agriculture Organization |location=Rome |url=http://www.virtualcentre.org/en/library/key_pub/longshad/A0701E00.pdf |title=Livestock's Long Shadow – Environmental issues and options |access-date=5 December 2008}}</ref> Through deforestation and [[land degradation]], livestock is also driving reductions in biodiversity. A well documented phenomenon is [[woody plant encroachment]], caused by [[overgrazing]] in rangelands.<ref>{{Citation |last1=Archer |first1=Steven R. |title=Woody Plant Encroachment: Causes and Consequences |date=2017 |work=Rangeland Systems |pages=25–84 |editor-last=Briske |editor-first=David D. |place=Cham |publisher=Springer International Publishing |doi=10.1007/978-3-319-46709-2_2 |isbn=978-3-319-46707-8 |last2=Andersen |first2=Erik M. |last3=Predick |first3=Katharine I. |last4=Schwinning |first4=Susanne |last5=Steidl |first5=Robert J. |last6=Woods |first6=Steven R. |doi-access=free}}</ref> Furthermore, the [[United Nations Environment Programme]] (UNEP) states that "[[methane emissions]] from global livestock are projected to increase by 60 per cent by 2030 under current practices and consumption patterns."<ref name="unep.org" />

=== Land and water issues ===
{{See also|Environmental impact of irrigation}}
[[File:Share Of Water Withdrawal By Agriculture In Total Withdrawal, Top Countries (2020).svg|thumb|440x440px|Countries with the highest share of water withdrawal by agriculture in total withdrawal.]]
[[File:Crops Kansas AST 20010624.jpg|thumb|upright=1.1|Circular [[irrigated]] crop fields in [[Haskell County, Kansas|Kansas]]. Healthy, growing crops of [[maize|corn]] and [[sorghum]] are green (sorghum may be slightly paler). Wheat is brilliant gold. Fields of brown have been recently harvested and plowed or have lain in [[fallow]] for the year.]]

Land transformation, the use of land to yield goods and services, is the most substantial way humans alter the Earth's ecosystems, and is the driving force causing [[biodiversity loss]]. Estimates of the amount of land transformed by humans vary from 39 to 50%.<ref name="Vitousek">{{cite journal |last1=Vitousek |first1=P. M. |last2=Mooney |first2=H. A. |last3=Lubchenco |first3=J. |last4=Melillo |first4=J. M. |year=1997 |title=Human Domination of Earth's Ecosystems |journal=[[Science (journal)|Science]] |volume=277 |pages=494–499 |doi=10.1126/science.277.5325.494 |issue=5325 |citeseerx=10.1.1.318.6529 |s2cid=8610995}}</ref> It is estimated that 24% of land globally experiences land degradation, a long-term decline in ecosystem function and productivity, with cropland being disproportionately affected.<ref name="FAO GLADA">{{cite web |last1=Bai |first1=Z.G. |last2=Dent |first2=D.L. |last3=Olsson |first3=L. |last4=Schaepman |first4=M.E. |name-list-style=amp |date=November 2008 |title=Global assessment of land degradation and improvement: 1. identification by remote sensing |publisher=[[Food and Agriculture Organization]]/ISRIC |url=http://www.isric.org/isric/webdocs/docs/Report%202008_01_GLADA%20international_REV_Nov%202008.pdf |access-date=24 May 2013 |url-status=dead |archive-url=https://web.archive.org/web/20131213041558/http://www.isric.org/isric/webdocs/docs/Report%202008_01_GLADA%20international_REV_Nov%202008.pdf |archive-date=13 December 2013}}</ref> Land management is the driving factor behind degradation; 1.5&nbsp;billion people rely upon the degrading land. Degradation can be through deforestation, [[desertification]], [[soil erosion]], mineral depletion, [[soil acidification|acidification]], or [[Soil salinity|salinization]].<ref name="CS" /> In 2021, the global agricultural land area was 4.79 billion hectares (ha), down 2 percent, or 0.09 billion ha compared with 2000. Between 2000 and 2021, roughly two-thirds of agricultural land were used for permanent meadows and pastures (3.21 billion ha in 2021), which declined by 5 percent (0.17 billion ha). One-third of the total agricultural land was cropland (1.58 billion ha in 2021), which increased by 6 percent (0.09 billion ha).<ref name=":14"/>

[[Eutrophication]], excessive nutrient enrichment in [[aquatic ecosystem]]s resulting in [[algal bloom]]s and [[anoxic waters|anoxia]], leads to [[fish kill]]s, [[loss of biodiversity]], and renders water unfit for drinking and other industrial uses. Excessive fertilization and manure application to cropland, as well as high livestock stocking densities cause nutrient (mainly [[nitrogen]] and [[phosphorus]]) [[surface runoff|runoff]] and [[leaching (agriculture)|leaching]] from agricultural land. These nutrients are major [[nonpoint source pollution|nonpoint pollutants]] contributing to [[eutrophication]] of aquatic ecosystems and pollution of groundwater, with harmful effects on human populations.<ref name="Eutr">{{cite journal |last1=Carpenter |first1=S. R. |last2=Caraco |first2=N. F. |last3=Correll |first3=D. L. |last4=Howarth |first4=R. W. |last5=Sharpley |first5=A. N. |last6=Smith |first6=V. H. |year=1998 |title=Nonpoint Pollution of Surface Waters with Phosphorus and Nitrogen |journal=Ecological Applications |volume=8 |pages=559–568 |doi=10.1890/1051-0761(1998)008[0559:NPOSWW]2.0.CO;2 |issue=3 |hdl=1808/16724 |hdl-access=free}}</ref> Fertilizers also reduce terrestrial biodiversity by increasing competition for light, favoring those species that are able to benefit from the added nutrients.<ref name="Hautier Niklaus Hector">{{cite journal |last1=Hautier |first1=Y. |last2=Niklaus |first2=P. A. |last3=Hector |first3=A. |title=Competition for Light Causes Plant Biodiversity Loss After Eutrophication |journal=Science |volume=324 |issue=5927 |date=2009 |doi=10.1126/science.1169640 |pmid=19407202 |pages=636–638 |bibcode=2009Sci...324..636H |s2cid=21091204 |url=https://www.zora.uzh.ch/id/eprint/18666/2/Hautier_2009.pdf |type=Submitted manuscript |access-date=3 November 2018 |archive-date=2 November 2018 |archive-url=https://web.archive.org/web/20181102011324/https://www.zora.uzh.ch/id/eprint/18666/2/Hautier_2009.pdf |url-status=live}}</ref>

Agriculture simultaneously is facing growing freshwater demand and precipitation anomalies (droughts, floods, and extreme rainfall and weather events) on rainfed areas fields and grazing lands.<ref name=":9" /> Agriculture accounts for 70 percent of withdrawals of freshwater resources,<ref>{{cite web |editor-last=Molden |editor-first=D. |url=http://www.iwmi.cgiar.org/About_IWMI/Strategic_Documents/Annual_Reports/2006_2007/pdf/IWMI%20Annual%20Report%202006-07.pdf |title=Findings of the Comprehensive Assessment of Water Management in Agriculture |website=Annual Report 2006/2007 |publisher=[[International Water Management Institute]] |access-date=6 January 2014 |url-status=live |archive-url=https://web.archive.org/web/20140107031305/http://www.iwmi.cgiar.org/About_IWMI/Strategic_Documents/Annual_Reports/2006_2007/pdf/IWMI%20Annual%20Report%202006-07.pdf |archive-date=7 January 2014}}</ref><ref>{{Cite book |title=On Water |url=https://www.eib.org/en/publications/eib-big-ideas-on-water |access-date=7 December 2020 |year=2019 |doi=10.2867/509830 |author1=European Investment Bank |author2=Arthus-Bertrand, Yann |publisher=Publications Office of the European Union |isbn=978-9286143199 |archive-date=29 November 2020 |archive-url=https://web.archive.org/web/20201129051604/https://www.eib.org/en/publications/eib-big-ideas-on-water |url-status=live}}</ref> and an estimated 41 percent of current global irrigation water use occurs at the expense of environmental flow requirements.<ref name=":9" /> It is long known that aquifers in areas as diverse as northern China, the [[Ganges|Upper Ganges]] and the western US are being depleted, and new research extends these problems to aquifers in Iran, Mexico and Saudi Arabia.<ref>{{cite web |url=http://green.blogs.nytimes.com/2012/08/13/stressed-aquifers-around-the-globe/ |title=Stressed Aquifers Around the Globe |last=Li |first=Sophia |date=13 August 2012 |access-date=7 May 2013 |website=[[The New York Times]] |url-status=live |archive-url=https://web.archive.org/web/20130402141530/http://green.blogs.nytimes.com/2012/08/13/stressed-aquifers-around-the-globe/ |archive-date=2 April 2013}}</ref> Increasing pressure is being placed on water resources by industry and urban areas, meaning that [[water scarcity]] is increasing and agriculture is facing the challenge of producing more food for the world's growing population with reduced water resources.<ref>{{cite web |url=http://www.fao.org/ag/magazine/0511sp2.htm |title=Water Use in Agriculture |date=November 2005 |publisher=[[Food and Agriculture Organization]] |access-date=7 May 2013 |url-status=dead |archive-url=https://archive.today/20130615091527/http://www.fao.org/ag/magazine/0511sp2.htm |archive-date=15 June 2013}}</ref> While industrial withdrawals have declined in the past few decades and municipal withdrawals have increased only marginally since 2010, agricultural withdrawals have continued to grow at an ever faster pace.<ref name=":9" /> [[Farm water|Agricultural water]] usage can also cause major environmental problems, including the destruction of natural wetlands, the spread of water-borne diseases, and land degradation through salinization and waterlogging, when irrigation is performed incorrectly.<ref>{{cite web |url=http://www.fao.org/ag/magazine/0303sp1.htm |title=Water Management: Towards 2030 |date=March 2003 |publisher=[[Food and Agriculture Organization]] |access-date=7 May 2013 |url-status=dead |archive-url=https://web.archive.org/web/20130510184315/http://www.fao.org/ag/magazine/0303sp1.htm |archive-date=10 May 2013}}</ref>

=== Pesticides ===
{{Main|Environmental impact of pesticides}}
[[File:Crop spraying near St Mary Bourne - geograph.org.uk - 392462.jpg|thumb|Spraying a crop with a [[pesticide]]]]

Pesticide use has increased since 1950 to 2.5&nbsp;million short tons annually worldwide, yet crop loss from pests has remained relatively constant.<ref name="Pimentel pesticide">{{cite web |author1=Pimentel, D. |author2=Culliney, T. W. |author3=Bashore, T. |year=1996 |url=http://ipmworld.umn.edu/chapters/pimentel.htm |archive-url=https://web.archive.org/web/19990218073023/http://ipmworld.umn.edu/chapters/pimentel.htm |url-status=dead |archive-date=18 February 1999 |title=Public health risks associated with pesticides and natural toxins in foods |website=Radcliffe's IPM World Textbook |access-date=7 May 2013}}</ref> The World Health Organization estimated in 1992 that three million pesticide poisonings occur annually, causing 220,000 deaths.<ref name="WHO">''Our planet, our health: Report of the WHO commission on health and environment''. Geneva: [[World Health Organization]] (1992).</ref> Pesticides select for [[pesticide resistance]] in the pest population, leading to a condition termed the "pesticide treadmill" in which pest resistance warrants the development of a new pesticide.<ref name="CS Pest">"Strategies for Pest Control", pp. 355–383 in [[#Chrispeels|Chrispeels]]</ref>

An alternative argument is that the way to "save the environment" and prevent famine is by using pesticides and intensive high yield farming, a view exemplified by a quote heading the Center for Global Food Issues website: 'Growing more per acre leaves more land for nature'.<ref name="DAvery">{{cite book |last=Avery |first=D.T. |year=2000 |title=Saving the Planet with Pesticides and Plastic: The Environmental Triumph of High-Yield Farming |url=https://archive.org/details/savingplanetwith00aver |url-access=registration |publisher=[[Hudson Institute]] |location=Indianapolis |isbn=978-1558130692}}</ref><ref>{{cite web |publisher=cgfi.org |url=http://www.cgfi.org |title=Center for Global Food Issues |access-date=14 July 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160716190009/http://www.cgfi.org/ |archive-date=16 July 2016}}</ref> However, critics argue that a trade-off between the environment and a need for food is not inevitable,<ref name="WH">{{cite book |last1=Lappe |first1=F. M. |last2=Collins |first2=J. |last3=Rosset |first3=P. |date=1998 |chapter-url=http://oregonstate.edu/instruct/bi430-fs430/Documents-2004/10B-DEVEL%20WORLD/World%20Hunger--Twelve%20Myths.pdf |chapter=Myth 4: Food vs. Our Environment |url-status=dead |archive-url=https://web.archive.org/web/20210304102909/http://oregonstate.edu/instruct/bi430-fs430/Documents-2004/10B-DEVEL%20WORLD/World%20Hunger--Twelve%20Myths.pdf |archive-date=4 March 2021 |pages=42–57 |title=World Hunger, Twelve Myths |publisher=Grove Press |location=New York |isbn=978-0802135919 |via=Oregon State University}}</ref> and that pesticides can replace [[good agricultural practices|good agronomic practices]] such as crop rotation.<ref name="CS Pest" /> The [[Push–pull agricultural pest management]] technique involves intercropping, using plant aromas to repel pests from crops (push) and to lure them to a place from which they can then be removed (pull).<ref name=PushPull>{{Cite journal |author1=Cook, Samantha M. |author2=Khan, Zeyaur R. |author3=Pickett, John A. |year=2007 |title=The use of push-pull strategies in integrated pest management |journal=Annual Review of Entomology |volume=52 |pages=375–400 |doi=10.1146/annurev.ento.52.110405.091407 |pmid=16968206}}</ref>

=== Contribution to climate change ===
{{Main|2 = Greenhouse gas emissions from agriculture}}
[[File:World Farm-gate Greenhouse Gas Emissions By Activity.svg|thumb|World farm-gate greenhouse gas emissions by activity]]
Agriculture contributes towards [[climate change]] through [[greenhouse gas emissions]] and by the conversion of non-agricultural land such as [[forest]]s into agricultural land.<ref>Section 4.2: Agriculture's current contribution to greenhouse gas emissions, in: {{cite book |author=HLPE |title=Food security and climate change. A report by the High Level Panel of Experts (HLPE) on Food Security and Nutrition of the Committee on World Food Security |url=http://www.fao.org/cfs/cfs-hlpe/reports/hlpe-food-security-and-climate-change-report-elaboration-process/en/ |publisher=[[Food and Agriculture Organization of the United Nations]] |location=Rome, Italy |date=June 2012 |archive-url=https://web.archive.org/web/20141212075812/http://www.fao.org/cfs/cfs-hlpe/reports/hlpe-food-security-and-climate-change-report-elaboration-process/en/ |archive-date=12 December 2014 |pages=67–69}}</ref> The agriculture, forestry and land use sector contribute between 13% and 21% of global greenhouse gas emissions.<ref name="IPCC2022">{{cite book |chapter-url=https://ipcc.ch/report/ar6/wg3/downloads/report/IPCC_AR6_WGIII_Chapter07.pdf |chapter=Chapter 7: Agriculture, Forestry and Other Land Uses (AFOLU) |title=Climate Change 2022: Mitigation of Climate Change |display-authors=etal |last1=Nabuurs |first1=G-J. |last2=Mrabet |first2=R. |last3=Abu Hatab |first3=A. |last4=Bustamante |first4=M. |doi=10.1017/9781009157926.009 |page=750 |url=https://research.wur.nl/en/publications/agriculture-forestry-and-other-land-uses-afolu |url-status=live |archive-url=https://web.archive.org/web/20221226114238/https://ipcc.ch/report/ar6/wg3/downloads/report/IPCC_AR6_WGIII_Chapter07.pdf |archive-date=26 December 2022}}.</ref> Emissions of [[nitrous oxide]], [[methane]] make up over half of total greenhouse gas emission from agriculture.<ref name="FAO2020">{{cite report |author=FAO |year=2020 |title=Emissions due to agriculture. Global, regional and country trends 2000–2018. |issn=2709-0078 |series=FAOSTAT Analytical Brief Series |url=https://www.fao.org/3/cb3808en/cb3808en.pdf |url-status=live |archive-url=https://web.archive.org/web/20210617210116/https://www.fao.org/3/cb3808en/cb3808en.pdf |archive-date=17 June 2021 |volume=18 |location=Rome |page=2}}</ref> [[Animal husbandry]] is a major source of greenhouse gas emissions.<ref>{{Cite web |title=How livestock farming affects the environment |url=https://www.downtoearth.org.in/factsheet/how-livestock-farming-affects-the-environment-64218 |access-date=10 February 2022 |website=www.downtoearth.org.in |archive-date=30 January 2023 |archive-url=https://web.archive.org/web/20230130055211/https://www.downtoearth.org.in/factsheet/how-livestock-farming-affects-the-environment-64218 |url-status=dead}}</ref>

Approximately 57% of global GHG emissions from the production of food are from the production of animal-based food while plant-based foods contribute 29% and the remaining 14% is for other utilizations.<ref name=":12">{{Cite journal |last1=Xu |first1=Xiaoming |last2=Sharma |first2=Prateek |last3=Shu |first3=Shijie |last4=Lin |first4=Tzu-Shun |last5=Ciais |first5=Philippe |last6=Tubiello |first6=Francesco N. |last7=Smith |first7=Pete |last8=Campbell |first8=Nelson |last9=Jain |first9=Atul K. |date=2021 |title=Global greenhouse gas emissions from animal-based foods are twice those of plant-based foods |url=https://www.nature.com/articles/s43016-021-00358-x |journal=Nature Food |volume=2 |issue=9 |pages=724–732 |doi=10.1038/s43016-021-00358-x |pmid=37117472 |hdl=2164/18207 |s2cid=240562878 |issn=2662-1355 |hdl-access=free |access-date=14 March 2023 |archive-date=3 April 2023 |archive-url=https://web.archive.org/web/20230403203405/https://www.nature.com/articles/s43016-021-00358-x |url-status=live}}</ref> Farmland management and [[land-use change]] represented major shares of total emissions (38% and 29%, respectively), whereas rice and beef were the largest contributing plant- and animal-based commodities (12% and 25%, respectively).<ref name=":12" /> South and Southeast Asia and South America were the largest emitters of production-based GHGs.<ref name=":12" />

=== Effects of climate change on agriculture ===
{{Further|Effects of climate change on agriculture}}
Climate change put significant part of crops in danger already at 1.5 degrees of warming. While in North Anerica, Europe and central Asia the share of endangered crops is relatively little at this level of warming, in the [[Climate change in the Middle East and North Africa|Middle east and North Africa]] region for example, close to 50% of cropland is in danger. With further temperature rise the risk increase in all regions, in some more, in some less. Globally the cropland area in safe climatic zone decrease for all the major crop groups as warming exceed 1.5 degrees.<ref>{{cite journal |last1=Heikonen |first1=Sara |last2=Heino |first2=Matias |last3=Jalava |first3=Mika |last4=Siebert |first4=Stefan |last5=Viviroli |first5=Daniel |last6=Kummu |first6=Matti |title=Climate change threatens crop diversity at low latitudes |journal=Nature Food |date=4 March 2025 |volume=6 |issue=4 |pages=331–342 |doi=10.1038/s43016-025-01135-w |quote=At the level of crop groups, the global net change in cropland area within the SCS would be negative in all groups if global warming exceeded 1.5 °C |doi-access=free |pmid=40038529 |pmc=12018264 }}</ref><ref>{{cite web |title=Over 50% global crop production could be threatened at 1.5-2°C warming |url=https://www.downtoearth.org.in/climate-change/over-50-global-crop-production-could-be-threatened-at-15-2c-warming |website=Down to Earth |date=6 March 2025 |publisher=Nature Food |access-date=12 March 2025}}</ref>

=== Sustainability ===
[[File:TerracesBuffers.JPG|thumb|upright|Terraces, [[conservation tillage]] and conservation buffers reduce [[soil erosion]] and [[water pollution]] on this farm in Iowa.]]
{{main|Sustainable agriculture}}

Current farming methods have resulted in over-stretched water resources, high levels of erosion and reduced soil fertility. There is not enough water to continue farming using current practices; therefore how water, land, and [[ecosystem]] resources are used to boost crop yields must be reconsidered. A solution would be to give value to ecosystems, recognizing environmental and livelihood tradeoffs, and balancing the rights of a variety of users and interests.<ref>{{cite web |editor-last=Boelee |editor-first=E. |url=http://www.iwmi.cgiar.org/topics/ecosystems/ |title=Ecosystems for water and food security |year=2011 |publisher=IWMI/UNEP |access-date=24 May 2013 |url-status=live |archive-url=https://web.archive.org/web/20130523025920/http://www.iwmi.cgiar.org/Topics/Ecosystems/ |archive-date=23 May 2013}}</ref> Inequities that result when such measures are adopted would need to be addressed, such as the reallocation of water from poor to rich, the clearing of land to make way for more productive farmland, or the preservation of a wetland system that limits fishing rights.<ref>{{cite web |last=Molden |first=D. |url=http://www.iwmi.cgiar.org/news_room/pdf/The-scientist_com-Opinion_The%20Water_Deficit.pdf |title=Opinion: The Water Deficit |publisher=[[The Scientist (magazine)|The Scientist]] |access-date=23 August 2011 |url-status=live |archive-url=https://web.archive.org/web/20120113125654/http://www.iwmi.cgiar.org/news_room/pdf/The-scientist_com-Opinion_The%20Water_Deficit.pdf |archive-date=13 January 2012}}</ref>

Technological advancements help provide farmers with tools and resources to make farming more sustainable.<ref>{{cite web |url=http://croplife.intraspin.com/pesticides/paper.asp?id=461 |author=Safefood Consulting, Inc. |title=Benefits of Crop Protection Technologies on Canadian Food Production, Nutrition, Economy and the Environment |year=2005 |publisher=CropLife International |access-date=24 May 2013 |url-status=dead |archive-url=https://archive.today/20130706005846/http://croplife.intraspin.com/pesticides/paper.asp?id=461 |archive-date=6 July 2013}}</ref> Technology permits innovations like [[conservation tillage]], a farming process which helps prevent land loss to erosion, reduces water pollution, and enhances [[carbon sequestration]].<ref>{{cite journal |author=Trewavas, Anthony |title=A critical assessment of organic farming-and-food assertions with particular respect to the UK and the potential environmental benefits of no-till agriculture |journal=Crop Protection |year=2004 |pages=757–781 |doi=10.1016/j.cropro.2004.01.009 |volume=23 |issue=9 |bibcode=2004CrPro..23..757T}}</ref>

Agricultural automation can help address some of the challenges associated with climate change and thus facilitate adaptation efforts.<ref name=":5" /> For example, the application of digital automation technologies (e.g. in precision agriculture) can improve resource-use efficiency in conditions which are increasingly constrained for agricultural producers.<ref name=":5" /> Moreover, when applied to sensing and early warning, they can help address the uncertainty and unpredictability of weather conditions associated with accelerating climate change.<ref name=":5" />

Other potential sustainable practices include [[conservation agriculture]], [[agroforestry]], improved [[Convertible husbandry|grazing]], avoided grassland conversion, and [[biochar]].<ref>{{Cite journal |last1=Griscom |first1=Bronson W. |last2=Adams |first2=Justin |last3=Ellis |first3=Peter W. |last4=Houghton |first4=Richard A. |last5=Lomax |first5=Guy |last6=Miteva |first6=Daniela A. |last7=Schlesinger |first7=William H. |last8=Shoch |first8=David |last9=Siikamäki |first9=Juha V.|last10=Smith |first10=Pete |last11=Woodbury |first11=Peter |date=2017 |title=Natural climate solutions |journal=[[Proceedings of the National Academy of Sciences]] |volume=114 |issue=44 |pages=11645–11650 |doi=10.1073/pnas.1710465114 |pmid=29078344 |pmc=5676916 |bibcode=2017PNAS..11411645G |issn=0027-8424 |doi-access=free}}</ref><ref>{{Cite book |title=Negative Emissions Technologies and Reliable Sequestration: A Research Agenda |publisher=National Academies of Sciences, Engineering, and Medicine |year=2019 |isbn=978-0-309-48452-7 |pages=117, 125, 135 |doi=10.17226/25259 |pmid=31120708 |last1=National Academies Of Sciences |first1=Engineering |s2cid=134196575}}</ref> Current mono-crop farming practices in the United States preclude widespread adoption of sustainable practices, such as 2–3 crop rotations that incorporate grass or hay with annual crops, unless negative emission goals such as soil carbon sequestration become policy.<ref>{{Cite book |url=https://www.nap.edu/catalog/25259/negative-emissions-technologies-and-reliable-sequestration-a-research-agenda |title=Negative Emissions Technologies and Reliable Sequestration: A Research Agenda |publisher=[[National Academies of Sciences, Engineering, and Medicine]] |year=2019 |isbn=978-0-309-48452-7 |page=97 |doi=10.17226/25259 |pmid=31120708 |author1=[[National Academies of Sciences, Engineering, and Medicine]] |s2cid=134196575 |access-date=21 February 2020 |archive-date=22 November 2021 |archive-url=https://web.archive.org/web/20211122220642/https://www.nap.edu/read/25259/chapter/1 |url-status=live}}</ref>

The food demand of Earth's projected population, with current climate change predictions, could be satisfied by improvement of agricultural methods, expansion of agricultural areas, and a sustainability-oriented consumer mindset.<ref>{{Cite book |url=https://www.journals.elsevier.com/ecological-modelling |title=Ecological Modelling |url-status=live |archive-url=https://web.archive.org/web/20180123072613/https://www.journals.elsevier.com/ecological-modelling |archive-date=23 January 2018}}</ref>

=== Energy dependence ===
[[File:Baumwoll-Erntemaschine auf Feld.jpeg|thumb|left|[[Mechanised agriculture|Mechanized agriculture]]: from the first models in the 1940s, tools like a [[cotton picker]] could replace 50 farm workers, at the price of increased use of [[fossil fuel]].]]

Since the 1940s, agricultural productivity has increased dramatically, due largely to the increased use of energy-intensive mechanization, fertilizers and pesticides. The vast majority of this energy input comes from [[fossil fuel]] sources.<ref>{{cite news |url=https://www.independent.co.uk/news/science/world-oil-supplies-are-set-to-run-out-faster-than-expected-warn-scientists-453068.html |title=World oil supplies are set to run out faster than expected, warn scientists |archive-url=https://web.archive.org/web/20101021233714/http://www.independent.co.uk/news/science/world-oil-supplies-are-set-to-run-out-faster-than-expected-warn-scientists-453068.html |archive-date=21 October 2010 |work=[[The Independent]] |date=14 June 2007 |access-date=14 July 2016}}</ref> Between the 1960s and the 1980s, the Green Revolution transformed agriculture around the globe, with world grain production increasing significantly (between 70% and 390% for wheat and 60% to 150% for rice, depending on geographic area)<ref>{{cite web |title=The Future of the Green Revolution: Implications for International Grain Markets |last=Herdt |first=Robert W. |url=http://www.rockefellerfoundation.org/uploads/files/06132caf-3d72-49e4-817d-ae89e0249d18.pdf |publisher=The Rockefeller Foundation |date=30 May 1997 |access-date=16 April 2013 |page=2 |url-status=live |archive-url=https://web.archive.org/web/20121019153636/http://www.rockefellerfoundation.org/uploads/files/06132caf-3d72-49e4-817d-ae89e0249d18.pdf |archive-date=19 October 2012}}</ref> as [[world population]] doubled. Heavy reliance on [[petrochemical]]s has raised concerns that oil shortages could increase costs and reduce agricultural output.<ref name="ncseonline.org" />

Industrialized agriculture depends on [[fossil fuels]] in two fundamental ways: direct consumption on the farm and manufacture of inputs used on the farm. Direct consumption includes the use of lubricants and fuels to operate farm vehicles and machinery.<ref name="ncseonline.org">{{cite web |last=Schnepf |first=Randy |date=19 November 2004 |title=Energy use in Agriculture: Background and Issues |website=CRS Report for Congress |url=http://www.nationalaglawcenter.org/wp-content/uploads/assets/crs/RL32677.pdf |publisher=[[Congressional Research Service]] |access-date=26 September 2013 |url-status=live |archive-url=https://web.archive.org/web/20130927190908/http://www.nationalaglawcenter.org/wp-content/uploads/assets/crs/RL32677.pdf |archive-date=27 September 2013}}</ref>

Indirect consumption includes the manufacture of fertilizers, pesticides, and farm machinery.<ref name="ncseonline.org" /> In particular, the production of [[nitrogen fertilizer]] can account for over half of agricultural energy usage.<ref>{{cite journal |title=Energy and the food system |last1=Woods |first1=Jeremy |last2=Williams |first2=Adrian |last3=Hughes |first3=John K. |last4=Black |first4=Mairi |last5=Murphy |first5=Richard |date=August 2010 |doi=10.1098/rstb.2010.0172 |pmid=20713398 |pmc=2935130 |journal=[[Philosophical Transactions of the Royal Society]] |volume=365 |pages=2991–3006 |issue=1554 |doi-access=free}}</ref> Together, direct and indirect consumption by US farms accounts for about 2% of the nation's energy use. Direct and indirect energy consumption by U.S. farms peaked in 1979, and has since gradually declined.<ref name="ncseonline.org" /> [[Food systems]] encompass not just agriculture but off-farm processing, packaging, transporting, marketing, consumption, and disposal of food and food-related items. Agriculture accounts for less than one-fifth of food system energy use in the US.<ref name="ers.usda.gov">{{cite web |author1=Canning, Patrick |author2=Charles, Ainsley |author3=Huang, Sonya |author4=Polenske, Karen R. |author5=Waters, Arnold |year=2010 |title=Energy Use in the U.S. Food System |website=USDA Economic Research Service Report No. ERR-94 |publisher=United States Department of Agriculture |url=http://www.ers.usda.gov/Publications/ERR94/ |url-status=dead |archive-url=https://web.archive.org/web/20100918182458/http://www.ers.usda.gov/publications/err94/ |archive-date=18 September 2010}}</ref><ref name="css.snre.umich.edu">{{cite web |last1=Heller |first1=Martin |last2=Keoleian |first2=Gregory |year=2000 |title=Life Cycle-Based Sustainability Indicators for Assessment of the U.S. Food System |publisher=University of Michigan Center for Sustainable Food Systems |url=http://css.snre.umich.edu/css_doc/CSS00-04.pdf |access-date=17 March 2016 |url-status=dead |archive-url=https://web.archive.org/web/20160314094203/http://css.snre.umich.edu/css_doc/CSS00-04.pdf |archive-date=14 March 2016}}</ref>

=== Plastic pollution ===
{{Main|Plastic pollution|plasticulture}}
Plastic products are used extensively in agriculture, including to increase crop yields and improve the efficiency of water and agrichemical use. "Agriplastic" products include films to cover [[greenhouse]]s and tunnels, mulch to cover soil (e.g. to suppress weeds, [[Water conservation|conserve water]], increase soil temperature and aid fertilizer application), shade cloth, pesticide containers, seedling trays, protective mesh and irrigation tubing. The polymers most commonly used in these products are low- density polyethylene (LPDE), linear low-density polyethylene (LLDPE), polypropylene (PP) and polyvinyl chloride (PVC).<ref name=":0">{{Cite web |author=UN Environment |date=21 October 2021 |title=Drowning in Plastics – Marine Litter and Plastic Waste Vital Graphics |url=http://www.unep.org/resources/report/drowning-plastics-marine-litter-and-plastic-waste-vital-graphics |access-date=23 March 2022 |website=UNEP – UN Environment Programme |archive-date=21 March 2022 |archive-url=https://web.archive.org/web/20220321122658/https://www.unep.org/resources/report/drowning-plastics-marine-litter-and-plastic-waste-vital-graphics |url-status=live}}</ref>

The total amount of plastics used in agriculture is difficult to quantify. A 2012 study reported that almost 6.5&nbsp;million tonnes per year were consumed globally while a later study estimated that global demand in 2015 was between 7.3&nbsp;million and 9 million tonnes. Widespread use of plastic mulch and lack of systematic collection and management have led to the generation of large amounts of mulch residue. Weathering and degradation eventually cause the mulch to fragment. These fragments and larger pieces of plastic accumulate in soil. Mulch residue has been measured at levels of 50 to 260&nbsp;kg per hectare in topsoil in areas where mulch use dates back more than 10 years, which confirms that mulching is a major source of both microplastic and macroplastic [[soil contamination]].<ref name=":0" />

Agricultural plastics, especially plastic films, are not easy to recycle because of high contamination levels (up to 40–50% by weight contamination by pesticides, fertilizers, soil and debris, moist vegetation, silage juice water, and UV stabilizers) and collection difficulties . Therefore, they are often buried or abandoned in fields and watercourses or burned. These disposal practices lead to soil degradation and can result in contamination of soils and leakage of [[microplastics]] into the marine environment as a result of precipitation run-off and tidal washing. In addition, additives in residual plastic film (such as UV and thermal stabilizers) may have deleterious effects on crop growth, soil structure, nutrient transport and salt levels. There is a risk that plastic mulch will deteriorate [[soil quality]], deplete soil organic matter stocks, increase soil water repellence and emit greenhouse gases. Microplastics released through fragmentation of agricultural plastics can absorb and concentrate contaminants capable of being passed up the trophic chain.<ref name=":0" />