Editing Green Revolution (section)

===Environmental impact===
{{More citations needed section|date=June 2021}}
[[File:Irrigation1.jpg|thumb|Increased use of irrigation played a major role in the green revolution.]]

====Biodiversity====
There are varying opinions about the effect of the Green Revolution on wild biodiversity. One hypothesis speculates that by increasing production per unit of land area, agriculture will not need to expand into new, uncultivated areas to feed a growing human population.<ref name=Davies2003>{{cite journal| last=Davies| first=Paul| title=An Historical Perspective from the Green Revolution to the Gene Revolution| journal=Nutrition Reviews| volume=61| issue=6| pages=S124–34|date=June 2003| doi=10.1301/nr.2003.jun.S124-S134| pmid=12908744| doi-access=free}}</ref> However, [[land degradation]] and [[Plant nutrients in soil|soil nutrients]] depletion have forced farmers to clear  forested areas in order to maintain production.<ref name="Shiva1991">{{cite journal| last=Shiva| first=Vandana| title=The Green Revolution in the Punjab| journal=The Ecologist| volume=21| issue=2| pages=57–60|date=March–April 1991}}</ref> A counter-hypothesis speculates that biodiversity was sacrificed because traditional systems of agriculture that were displaced sometimes incorporated practices to preserve wild biodiversity, and because the Green Revolution expanded agricultural development into new areas where it was once unprofitable or too [[arid]]. For example, the development of wheat varieties tolerant to acid soil conditions with high aluminium content permitted the introduction of agriculture in the [[Cerrado]] [[tropical savanna climate|semi-humid]] [[tropical savanna]].<ref name="Davies2003"/> 

The world community has clearly acknowledged the negative aspects of [[agricultural expansion]] as the 1992 [[Earth Summit|Rio Treaty]], signed by 189 nations, has generated numerous national [[Biodiversity action plan|Biodiversity Action Plans]] which assign significant [[biodiversity loss]] to agriculture's expansion into new domains.

The Green Revolution has been criticized for an agricultural model which relied on a few staple and market profitable crops, and pursuing a model which limited the biodiversity of Mexico. One of the critics against these techniques  and the Green Revolution as a whole was [[Carl O. Sauer]], a geography professor at the [[University of California, Berkeley]]. According to Sauer these techniques of plant breeding would result in negative effects on the country's resources, and the culture:

<blockquote>
A good aggressive bunch of American agronomists and plant breeders could ruin the native resources for good and all by pushing their American commercial stocks... And Mexican agriculture cannot be pointed toward standardization on a few commercial types without upsetting native economy and culture hopelessly... Unless the Americans understand that, they'd better keep out of this country entirely. That must be approached from an appreciation of native economies as being basically sound.<ref>{{Cite book |last=Jennings |first=Bruce H. |title=Foundations of international agricultural research: Science and politics in Mexican Agriculture |publisher=Westview Press |year=1988 |location=Boulder |page=51}}</ref>
</blockquote>

==== Greenhouse gas emissions ====
Studies indicate that the Green Revolution has substantially increased emissions of the greenhouse gas {{CO2}}.<ref>{{cite journal |last1=Liu |first1=Xinrui |last2=Zhang |first2=Xiaodong |last3=Huang |first3=Yufei |last4=Chen |first4=Kaijie |last5=Wang |first5=Linfei |last6=Ma |first6=Jianmin |last7=Huang |first7=Tao |last8=Zhao |first8=Yuan |last9=Gao |first9=Hong |last10=Tao |first10=Shu |last11=Liu |first11=Junfeng |last12=Jian |first12=Xiaohu |last13=Luo |first13=Jinmu |title=The Direct Radiative Forcing Impact of Agriculture-Emitted Black Carbon Associated With India's Green Revolution |journal=Earth's Future |date=June 2021 |volume=9 |issue=6 |doi=10.1029/2021EF001975 |bibcode=2021EaFut...901975L |doi-access=free }}</ref> High yield agriculture has dramatic effects on the amount of carbon cycling in the atmosphere. The way in which farms are grown, in tandem with the seasonal [[Carbon cycle|carbon cycling]] of various crops, could alter the impact carbon in the atmosphere has on global warming. Wheat, rice, and soybean crops account for a significant amount of the increase in carbon in the atmosphere over the last 50 years.<ref>{{Cite web|url=http://www.climatecentral.org/news/green-revolution-brings-greater-co2-swings-18354|title='Green Revolution' Brings Greater {{CO2}} Swings|website=www.climatecentral.org|access-date=2016-10-10}}</ref> 

Poorly regulated applications of nitrogen fertilizer that exceed the amount used by plants, such as broadcast applications of [[urea]], result in emissions of [[nitrous oxide]], a potent greenhouse gas, and in water pollution.<ref name="WP122221">{{cite news |author1=Joshua Partlow |author2=Chris Mooney |title=Mexico's wheat fields help feed the world. They're also releasing a dangerous greenhouse gas. |url=https://www.washingtonpost.com/climate-environment/interactive/2021/mexico-fertilizer-nitrous-oxide-emissions/ |access-date=December 24, 2021 |newspaper=The Washington Post |date=December 22, 2021}}</ref> As the UN Special Rapporteur on the Right to Food, [[Michael Fakhri]] summarized in 2022, "food systems emit approximately one third of the world’s greenhouse gases and contribute to the alarming decline in the number of animal and plant species. Intensive industrial agriculture and export-oriented food policies have driven much of this damage. Ever since governments started adopting the Green Revolution in the 1950s, the world's food systems have been increasingly designed along industrial models, the idea being that, if people are able to purchase industrial inputs, then they can produce a large amount of food. Productivity was not measured in terms of human and environmental health, but exclusively in terms of commodity output and economic growth. This same system disrupted carbon, nitrogen and phosphorus cycles because it requires farmers to depend on fossil fuel- based machines and chemical inputs, displacing long-standing regenerative and integrated farming practices."<ref>{{Cite news |last=Fakhri |first=Michael |date=May 20, 2022 |title=Public statement by the United Nations Special Rapporteur on the right to food, Mr. Michael Fakhri}}</ref> The IPCC's synthesis of recent findings states similarly "intensive agriculture during the second half of the 20th century led to [[soil degradation]] and loss of natural resources and contributed to [[climate change]]."<ref name=":5" /> They further specify, "while the Green Revolution technologies substantially increased the yield of few crops and allowed countries to reduce hunger, they also resulted in inappropriate and excessive use of agrochemicals, inefficient water use, loss of beneficial biodiversity, water and soil pollution and significantly reduced crop and varietal diversity."

==== Land use ====
A 2021 study found that the Green Revolution led to a reduction in land used for agriculture.<ref name=":1" />