View source for Earth:Climate change and agriculture

{{short description|Climate change's effects on agriculture}}
[[File:Greenhouse Gas Emissions by Economic Sector.svg|thumb|upright=1.5|right|Global greenhouse gas emissions attributed to different economic sectors as per the IPCC AR5 report. 3/4ths of emissions are directly produced, while 1/4th are produced by electricity and heat production that supports the sector.]]
[[File:Net crops tropicalvsworld.png|thumb|upright=1.5|Graph of net crop production worldwide and in selected tropical countries. Raw data from the United Nations.<ref>{{Cite web|url=http://www.fao.org/faostat/en/|title=FAOSTAT|website=www.fao.org}}</ref>]]

'''Climate change and agriculture''' are interrelated processes, both of which take place on a global scale. [[Earth:Global warming|Global warming]] affects [[Earth:Agriculture|agriculture]] in a number of ways, including through changes in [[Earth:Instrumental temperature record|average temperatures]], rainfall, and climate [[Earth:Extreme weather|extremes]] (e.g., [[Earth:Heat wave|heat wave]]s); changes in pests and [[Disease|disease]]s; changes in atmospheric [[Chemistry:Carbon dioxide|carbon dioxide]] and ground-level [[Chemistry:Ozone|ozone]] concentrations; changes in the [[Biology:Nutrition|nutrition]]al quality of some foods;<ref name=science-news>{{cite news |first=Susan |last=Milius | name-list-format = vanc |url= https://www.sciencenews.org/article/nutrition-climate-change-top-science-stories-2017-yir |title=Worries grow that climate change will quietly steal nutrients from major food crops|date=13 December 2017|work=Science News|access-date=21 January 2018}}</ref> and changes in sea level.<ref>Hoffmann, U., Section B: Agriculture - a key driver and a major victim of global warming, in: Lead Article, in: Chapter 1, in {{harvnb|Hoffmann|2013|pp=3, 5}}</ref>

Climate change is already affecting agriculture, with effects unevenly distributed across the world.<ref name="porter summary">Porter, J.R., ''et al''., Executive summary, in: [http://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap7_FINAL.pdf Chapter 7: Food security and food production systems] (archived [https://web.archive.org/web/20141105164634/https://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap7_FINAL.pdf 5 November 2014]), in {{harvnb|IPCC AR5 WG2 A|2014|pp=488–489}}
</ref> Future climate change will likely negatively affect [[Earth:Crop yield|crop production]] in low latitude countries, while effects in northern [[Earth:Latitude|latitude]]s may be positive or negative.<ref name="porter summary"/> Animal agriculture, although lesser than vehicles, is also responsible for {{CO2}} greenhouse gas production and a percentage of the world's methane, and future land infertility, and the displacement of local species.

Agriculture contributes to climate change both by anthropogenic emissions of [[Chemistry:Greenhouse gas|greenhouse gas]]es and by the conversion of non-agricultural land such as [[Earth:Forest|forest]]s into agricultural land.<ref>Section 4.2: Agriculture’s current contribution to greenhouse gas emissions, in: {{harvnb|HLPE|2012|pp=67–69}}
</ref><ref>{{Cite journal|last=Sarkodie|first=Samuel A.|last2=Ntiamoah|first2=Evans B.|last3=Li|first3=Dongmei|date=2019|title=Panel heterogeneous distribution analysis of trade and modernized agriculture on CO2 emissions: The role of renewable and fossil fuel energy consumption|url=https://onlinelibrary.wiley.com/doi/abs/10.1111/1477-8947.12183|journal=Natural Resources Forum|language=en|volume=43|issue=3|pages=135–153|doi=10.1111/1477-8947.12183|issn=1477-8947|doi-access=free}}</ref> In 2010, agriculture, forestry and land-use change were estimated to contribute 20–25% of global annual emissions.<ref>Blanco, G., ''et al''., Section 5.3.5.4: Agriculture, Forestry, Other Land Use, in: [http://report.mitigation2014.org/report/ipcc_wg3_ar5_chapter5.pdf Chapter 5: Drivers, Trends and Mitigation] (archived [https://web.archive.org/web/20141230092610/http://report.mitigation2014.org/report/ipcc_wg3_ar5_chapter5.pdf 30 December 2014)], in: {{harvnb|IPCC AR5 WG3|2014|p=383}} Emissions aggregated using 100-year [[Physics:Global warming potential|global warming potential]]s from the IPCC Second Assessment Report</ref>. In 2020, the [[Social:European Union|European Union]]'s Scientific Advice Mechanism estimated that the food system as a whole contributed 37% of total greenhouse gas emissions, and that this figure was on course to increase by 30–40% by 2050 due to population growth and dietary change.<ref>{{Cite book|last=Science Advice for Policy by European Academies|first=|url=https://www.sapea.info/wp-content/uploads/sustainable-food-system-report.pdf|title=A sustainable food system for the European Union|publisher=SAPEA|year=2020|isbn=978-3-9820301-7-3|location=Berlin|pages=39|doi=10.26356/sustainablefood}}</ref>

A range of policies can reduce the risk of negative climate change impacts on agriculture<ref>Porter, J.R., ''et al''., Section 7.5: Adaptation and Managing Risks in Agriculture and Other Food System Activities, in [http://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap7_FINAL.pdf Chapter 7: Food security and food production systems] (archived [https://web.archive.org/web/20141105164634/https://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap7_FINAL.pdf 5 November 2014]), in {{harvnb|IPCC AR5 WG2 A|2014|pp=513–520}}</ref><ref>Oppenheimer, M., ''et al''., Section 19.7. Assessment of Response Strategies to Manage Risks, in: [http://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap19_FINAL.pdf Chapter 19: Emergent risks and key vulnerabilities] (archived [https://web.archive.org/web/20141105164634/https://ipcc-wg2.gov/AR5/images/uploads/WGIIAR5-Chap19_FINAL.pdf 5 November 2014]), in {{harvnb|IPCC AR5 WG2 A|2014|p=1080}}</ref> and greenhouse gas emissions from the agriculture sector.<ref>SUMMARY AND RECOMMENDATIONS, in: {{harvnb|HLPE|2012|pp=12–23}}</ref><ref>Current climate change policies are described in {{harvnb|Annex I NC|2014}} and {{harvnb|Non-Annex I NC|2014}}</ref><ref>Smith, P., ''et al''., Executive summary, in: [http://report.mitigation2014.org/report/ipcc_wg3_ar5_chapter5.pdf Chapter 5: Drivers, Trends and Mitigation] (archived [https://web.archive.org/web/20141230092610/http://report.mitigation2014.org/report/ipcc_wg3_ar5_chapter5.pdf 30 December 2014)], in: {{harvnb|IPCC AR5 WG3|2014|pp=816–817}}
</ref>

== Impact of climate change on agriculture ==
[[File:Corn and soybean temperature response (ARS USDA).png|thumb|upright=2|right|alt=refer to caption and image description|For each plant variety, there is an optimal temperature for vegetative growth, with growth dropping off as temperatures increase or decrease. Similarly, there is a range of temperatures at which a plant will produce seed. Outside of this range, the plant will not reproduce. As the graphs show, maize will fail to reproduce at temperatures above 95&nbsp;°F (35&nbsp;°C) and [[Biology:Soybean|soybean]] above 102&nbsp;°F (38.8&nbsp;°C).<ref>{{Include-USGov
 | agency=US Global Change Research Program (USGCRP)
 | source={{cite web |title=Corn and Soybean Temperature Response |url=http://nca2009.globalchange.gov/corn-and-soybean-temperature-response |access-date=2013-05-30 |url-status=dead |archive-url=https://web.archive.org/web/20130512133320/http://nca2009.globalchange.gov/corn-and-soybean-temperature-response |archive-date=12 May 2013}}, in: {{citation
 |year            = 2017
 |title           = Global Climate Change Impacts in the United States
 |editor          = Karl, T.R.
 |publisher       = Cambridge University Press
 |isbn            = 978-0-521-14407-0
 |url             = http://nca2009.globalchange.gov/
 |display-editors = etal
}}
}}
</ref>]]
Despite technological advances, such as improved varieties, genetically modified organisms, and [[Earth:Irrigation|irrigation]] systems, weather is still a key factor in agricultural productivity, as well as [[Chemistry:Soil|soil]] properties and natural communities. The effect of climate on agriculture is related to variabilities in local climates rather than in global climate patterns. The Earth's average surface temperature has increased by 1.5&nbsp;°F (0.83&nbsp;°C) since 1880. Consequently, in making an assessment agronomists must consider each [[Earth:Ecoregion|local area]].

On the other hand, agricultural trade has grown in recent years, and now provides significant amounts of food, on a national level to major importing countries, as well as comfortable [[Finance:Gross domestic product|income]] to exporting ones. The international aspect of trade and security in terms of food implies the need to also consider the [[Biology:Effects of global warming|effects of climate change]] on a global scale.

A 2008 study published in ''Science'' suggested that, due to climate change, "southern Africa could lose more than 30% of its main crop, maize, by 2030. In South Asia losses of many regional staples, such as rice, millet and maize could top 10%".<ref>{{cite news | url=http://news.bbc.co.uk/2/hi/science/nature/7220807.stm | title=Climate 'could devastate crops' | date=31 January 2008 |work=BBC News}}</ref>{{sfn|Lobell|others|2008a}}

The [[Organization:Intergovernmental Panel on Climate Change|Intergovernmental Panel on Climate Change]] (IPCC) has produced several reports that have assessed the [[Scientific literature|scientific literature]] on climate change. The [[Earth:IPCC Third Assessment Report|IPCC Third Assessment Report]], published in 2001, concluded that the poorest countries would be hardest hit, with reductions in crop yields in most tropical and sub-tropical regions due to decreased water availability, and new or changed insect pest incidence. In Africa and Latin America many rainfed crops are near their maximum temperature tolerance, so that yields are likely to fall sharply for even small climate changes; falls in agricultural productivity of up to 30% over the 21st century are projected. Marine life and the fishing industry will also be severely affected in some places.

In the report published in 2014 the [[Organization:Intergovernmental Panel on Climate Change|Intergovernmental Panel on Climate Change]] says that the world may reach "a threshold of global warming beyond which current agricultural practices can no longer support large human civilizations." by the middle of the 21st century. In 2019 it published reports in which it says that millions already suffer from food insecurity due to climate change and predicted decline in global crop production of 2% - 6% by decade.<ref>{{cite web |last1=Smith |first1=K.R. |last2=Woodward |first2=A. |last3=Campbell-Lendrum |first3=D. |last4=Chadee |first4=D.D. |last5=Honda |first5=Y. |last6=Liu |first6=Q. |last7=Olwoch |first7=J.M. |last8=Revich |first8=B. |last9=Sauerborn |first9=R. |title=Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Chapter11: : Human health: impacts, adaptation, and co-benefits. Section: 11.8.2 (Limits to Food Production and Human Nutrition). Page 736. |url=https://www.ipcc.ch/site/assets/uploads/2018/02/WGIIAR5-Chap11_FINAL.pdf |website=Intergovermental Pannel On Climate Change |publisher=Intergovermental Pannel On Climate Change |accessdate=29 October 2019}}</ref><ref>{{cite news |last1=Little |first1=Amanda |title=Climate Change Is Likely to Devastate the Global Food Supply. But There's Still Reason to Be Hopeful |url=https://time.com/5663621/climate-change-food-supply/ |access-date=30 August 2019 |agency=Time |date=28 August 2019}}</ref>

Climate change can reduce yields by the amplification of [[Rossby wave|rossby wave]]s. There is a possibility that the effects are already existing.<ref>{{cite news |last1=Rosane |first1=Olivia |title=Study Finds 'Underexplored Vulnerability in the Food System': Jet Stream-Fueled Global Heat Waves |url=https://www.ecowatch.com/food-system-climate-change-2641559399.html |accessdate=11 December 2019 |agency=Ecowatch |date=10 December 2019}}</ref>

Climate change induced by increasing [[Chemistry:Greenhouse gas|greenhouse gas]]es is likely to affect crops differently from region to region. For example, average crop yield is expected to drop down to 50% in Pakistan according to the [[Company:Met Office|Met Office]] scenario whereas corn production in Europe is expected to grow up to 25% in optimum hydrologic conditions.

More favourable effects on yield tend to depend to a large extent on realization of the potentially beneficial effects of carbon dioxide on crop growth and increase of efficiency in water use. Decrease in potential yields is likely to be caused by shortening of the growing period, decrease in water availability and poor [[Biology:Vernalization|vernalization]].

In the long run, the climatic change could affect agriculture in several ways :
* ''productivity'', in terms of [[Quantity|quantity]] and [[Finance:Quality (business)|quality]] of crops
* ''agricultural practices'', through changes of water use (irrigation) and agricultural inputs such as [[Biology:Herbicide|herbicide]]s, [[Biology:Insecticide|insecticide]]s and [[Chemistry:Fertilizer|fertilizer]]s
* ''environmental effects'', in particular in relation of frequency and intensity of soil drainage (leading to nitrogen leaching), soil erosion, reduction of [[Biology:Biodiversity|crop diversity]]
* ''rural space'', through the loss and gain of cultivated lands, land [[Finance:Speculation|speculation]], land renunciation, and hydraulic amenities.
* ''adaptation'', organisms may become more or less competitive, as well as humans may develop urgency to develop more competitive organisms, such as flood resistant or [[Earth:Crop tolerance to seawater|salt resistant]] varieties of rice.

They are large uncertainties to uncover, particularly because there is lack of information on many specific local regions, and include the uncertainties on magnitude of climate change, the effects of technological changes on productivity, global food demands, and the numerous possibilities of adaptation.

Most agronomists believe that agricultural production will be mostly affected by the severity and pace of climate change, not so much by gradual trends in climate. If change is gradual, there may be enough time for biota adjustment. Rapid climate change, however, could harm agriculture in many countries, especially those that are already suffering from rather poor soil and climate conditions, because there is less time for optimum [[Biology:Natural selection|natural selection]] and adaption.

But much remains unknown about exactly how [[Earth:Climate change|climate change]] may affect farming and [[Earth:Food security|food security]], in part because the role of farmer behaviour is poorly captured by crop-climate models.  For instance, Evan Fraser, a geographer at the University of Guelph in Ontario {{wipe|Canada}}, has conducted a number of studies that show that the socio-economic context of farming may play a huge role in determining whether a [[Earth:Drought|drought]] has a major, or an insignificant impact on crop production.<ref>{{cite journal | last1 = Fraser | first1 = E | year = 2007a | title = Travelling in antique lands: Studying past famines to understand present vulnerabilities to climate change | journal = Climate Change | volume = 83 | issue = 4| pages = 495–514 | doi=10.1007/s10584-007-9240-9 | bibcode = 2007ClCh...83..495F}}</ref><ref name="Simelton, E. 2009">{{cite journal | vauthors = Simelton E, Fraser E, Termansen M | year = 2009 | title = Typologies of crop-drought vulnerability: an empirical analysis of the socio-economic factors that influence the sensitivity and resilience to drought of three major food crops in China (1961–2001) | journal = Environmental Science & Policy | volume = 12 | issue = 4| pages = 438–452 | doi=10.1016/j.envsci.2008.11.005}}</ref> In some cases, it seems that even minor droughts have big impacts on food security (such as what happened in Ethiopia in the early 1980s where a minor drought triggered a massive famine), versus cases where even relatively large weather-related problems were adapted to without much hardship.<ref>{{cite journal | vauthors = Fraser ED, Termansen M, Sun N, Guan D, Simelton E, Dodds P, Feng K, Yu Y | year = 2008 | title = Quantifying socio economic characteristics of drought sensitive regions: evidence from Chinese provincial agricultural data | journal = Comptes Rendus Geoscience | volume = 340 | issue = 9–10| pages = 679–688 | doi=10.1016/j.crte.2008.07.004| bibcode = 2008CRGeo.340..679F }}</ref> Evan Fraser combines socio-economic models along with climatic models to identify "vulnerability hotspots"<ref name="Simelton, E. 2009"/> One such study has identified US maize (corn) production as particularly vulnerable to climate change because it is expected to be exposed to worse droughts, but it does not have the socio-economic conditions that suggest farmers will adapt to these changing conditions.<ref>{{cite journal | vauthors = Fraser ED, Simelton E, Termansen M, Gosling SN, South A | year = 2013 | title = 'Vulnerability hotspots': integrating socio-economic and hydrological models to identify where cereal production may decline due to climate change induced drought | journal = Agricultural and Forest Meteorology | volume = 170 | pages = 195–205 | doi=10.1016/j.agrformet.2012.04.008 | bibcode = 2013AgFM..170..195F}}</ref> Other studies rely instead on projections of key agro-meteorological or agro-climate indices, such as growing season length, plant heat stress, or start of field operations, identified by land management stakeholders and that provide useful information on mechanisms driving climate change impact on agriculture.<ref>{{cite journal | vauthors = Harding AE, Rivington M, Mineter MJ, Tett SF | year = 2015 | title = Agro-meteorological indices and climate model uncertainty over the UK | journal = Climatic Change | volume = 128 | issue =1 | pages = 113–126 | doi=10.1007/s10584-014-1296-8| bibcode = 2015ClCh..128..113H | doi-access = free }}</ref><ref>{{cite journal | vauthors =Monier E, Xu L, Snyder R | year = 2016 | title = Uncertainty in future agro-climate projections in the United States and benefits of greenhouse gas mitigation | journal = Environmental Research Letters | volume = 11 | issue = 5 | pages = 055001 | doi=10.1088/1748-9326/11/5/055001| bibcode = 2016ERL....11e5001M | doi-access = free }}</ref>

=== Pest insects and climate change ===
Global warming could lead to an increase in pest insect populations, harming yields of staple crops like [[Biology:Wheat|wheat]], [[Biology:Soybean|soybean]]s, and corn.<ref name="Live Science">{{Cite news|url=http://www.livescience.com/4296-global-warming-trigger-insect-population-boom.html|title=Global Warming Could Trigger Insect Population Boom|work=Live Science|access-date=2017-05-02}}</ref> While warmer temperatures create longer growing seasons, and faster growth rates for plants, it also increases the metabolic rate and number of breeding cycles of insect populations.<ref name="Live Science"/> Insects that previously had only two breeding cycles per year could gain an additional cycle if warm growing seasons extend, causing a population boom. Temperate places and higher [[Earth:Latitude|latitude]]s are more likely to experience a dramatic change in insect populations.<ref>{{Cite journal|last=Stange|first=Erik| name-list-format = vanc |date=November 2010|title=Climate Change Impact: Insects|url=http://www.els.net/WileyCDA/ElsArticle/refId-a0022555.html|journal=Norwegian Institute for Nature Research}}</ref>

The [[Organization:University of Illinois at Urbana–Champaign|University of Illinois]] conducted studies to measure the effect of warmer temperatures on soybean plant growth and Japanese beetle populations.<ref name="Union of Concerned Scientists">{{Cite news|url=http://www.ucsusa.org/global_warming/science_and_impacts/impacts/Global-warming-insects.html#.WOwzzDvy|title=Crops, Beetles, and Carbon Dioxide|work=Union of Concerned Scientists|access-date=2017-05-02|language=en}}</ref> Warmer temperatures and elevated CO<sub>2</sub> levels were simulated for one field of soybeans, while the other was left as a control. These studies found that the soybeans with elevated CO<sub>2</sub> levels grew much faster and had higher yields, but attracted [[Biology:Japanese beetle|Japanese beetle]]s at a significantly higher rate than the control field.<ref name="Union of Concerned Scientists"/> The beetles in the field with increased CO<sub>2</sub> also laid more eggs on the soybean plants and had longer lifespans, indicating the possibility of a rapidly expanding population. DeLucia projected that if the project were to continue, the field with elevated CO<sub>2</sub> levels would eventually show lower yields than that of the control field.<ref name="Union of Concerned Scientists"/>

The increased CO<sub>2</sub> levels deactivated three genes within the soybean plant that normally create chemical defenses against pest insects. One of these defenses is a protein that blocks digestion of the soy leaves in insects. Since this gene was deactivated, the beetles were able to digest a much higher amount of plant matter than the beetles in the control field. This led to the observed longer lifespans and higher egg-laying rates in the experimental field.<ref name="Union of Concerned Scientists"/>

There are a few proposed solutions to the issue of expanding pest populations. One proposed solution is to increase the number of pesticides used on future crops.<ref name="agadapt.ucdavis.edu">{{Cite web|url=http://agadapt.ucdavis.edu/pestsdiseases/|title=Agricultural Adaptation to Climate Change|access-date=2 May 2017|archive-url=https://web.archive.org/web/20170504021853/http://agadapt.ucdavis.edu/pestsdiseases/|archive-date=4 May 2017|url-status=dead}}</ref> This has the benefit of being relatively cost effective and simple, but may be ineffective. Many pest insects have been building up an [[Biology:Pesticide resistance|immunity]] to these pesticides. Another proposed solution is to utilize [[Biology:Biological pest control|biological control agents]].<ref name="agadapt.ucdavis.edu"/> This includes things like planting rows of native vegetation in between rows of crops. This solution is beneficial in its overall environmental impact. Not only are more native plants getting planted, but pest insects are no longer building up an immunity to pesticides. However, planting additional native plants requires more room, which destroys additional acres of public land. The cost is also much higher than simply using pesticides.<ref>{{Cite journal|last=Stange|first=Erik| name-list-format = vanc |date=November 2010|title=Climate Change Impact: Insects|journal=Norwegian Institute for Nature Research}}</ref>

=== Plant diseases and climate change ===
Although research is limited, research has shown that climate change may alter the developmental stages of pathogens that can affect crops.<ref name=":0">{{cite journal | vauthors = Coakley SM, Scherm H, Chakraborty S | title = Climate change and plant disease management | journal = Annual Review of Phytopathology | volume = 37 | pages = 399–426 | date = September 1999 | pmid = 11701829 | doi = 10.1146/annurev.phyto.37.1.399 }}</ref> The biggest consequence of climate change on the dispersal of pathogens is that the geographical distribution of hosts and pathogens could shift, which would result in more crop losses.<ref name=":0" /> This could affect competition and recovery from disturbances of plants. It has been predicted that the effect of climate change will add a level of complexity to figuring out how to maintain sustainable agriculture.<ref name=":0" />

===Observed impacts===

Effects of regional climate change on agriculture have been limited.<ref name=rosen>{{cite book | vauthors = Rosenzweig C | contribution = Executive summary | title = Chapter 1: Assessment of Observed Changes and Responses in Natural and Managed Systems | series = Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change | publisher = Print version: CUP. This version: IPCC website | year = 2007 | location = Cambridge University Press (CUP): Cambridge, UK | isbn = 978-0-521-88010-7 | url = http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch1s1-es.html | veditors = Parry MC | access-date = 2011-06-25 | display-editors = etal | archive-url = https://web.archive.org/web/20181102223808/http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch1s1-es.html | archive-date = 2 November 2018 | url-status = dead }}</ref> Changes in crop [[Earth:Phenology|phenology]] provide important evidence of the response to recent regional climate change.<ref>{{cite book | vauthors = Rosenzweig C | contribution = 1.3.6.1 Crops and livestock | title = Chapter 1: Assessment of Observed Changes and Responses in Natural and Managed Systems | series = Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change | url = http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch1s1-3-6-1.html | veditors = Parry ML | publisher = Print version: CUP. This version: IPCC website | year = 2007 | location = Cambridge University Press (CUP): Cambridge, UK | isbn = 978-0-521-88010-7 | access-date = 2011-06-25 | display-editors = etal | archive-url = https://web.archive.org/web/20181103092229/http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch1s1-3-6-1.html | archive-date = 3 November 2018 | url-status = dead }}</ref> Phenology is the study of natural phenomena that recur periodically, and how these phenomena relate to climate and seasonal changes.<ref>{{cite book | contribution = Definition of "phenology" | title = Appendix I: Glossary | series = Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change | url = http://www.ipcc.ch/publications_and_data/ar4/wg2/en/annexessglossary-p-z.html | veditors = Parry ML | publisher = Print version: CUP. This version: IPCC website | year = 2007 | location = Cambridge University Press (CUP): Cambridge, UK | isbn = 978-0-521-88010-7 | access-date = 2011-06-25 | display-editors = etal | archive-url = https://web.archive.org/web/20111108191024/http://www.ipcc.ch/publications_and_data/ar4/wg2/en/annexessglossary-p-z.html | archive-date = 8 November 2011 | url-status = dead }}</ref> A significant advance in phenology has been observed for agriculture and forestry in large parts of the Northern Hemisphere.<ref name=rosen/>

Droughts have been occurring more frequently because of global warming and they are expected to become more frequent and intense in Africa, southern Europe, the Middle East, most of the Americas, Australia, and Southeast Asia.<ref>{{Cite journal | last1 = Dai | first1 = A. | doi = 10.1002/wcc.81 | title = Drought under global warming: A review | journal = Wiley Interdisciplinary Reviews: Climate Change | volume = 2 | pages = 45–65 | year = 2011 | url = https://zenodo.org/record/1229380 | bibcode = 2011AGUFM.H42G..01D }}</ref> Their impacts are aggravated because of increased water demand, population growth, urban expansion, and environmental protection efforts in many areas.<ref>{{Cite journal | vauthors = Mishra AK, Singh VP | doi = 10.1016/j.jhydrol.2011.03.049 | title = Drought modeling – A review | journal = Journal of Hydrology | volume = 403 | issue = 1–2 | pages = 157–175 | year = 2011 | bibcode = 2011JHyd..403..157M }}</ref> Droughts result in crop failures and the loss of pasture grazing land for livestock.<ref>{{Cite journal | vauthors = Ding Y, Hayes MJ, Widhalm M | doi = 10.1108/09653561111161752 | title = Measuring economic impacts of drought: A review and discussion | journal = Disaster Prevention and Management | volume = 20 | issue = 4 | pages = 434–446 | year = 2011 | url = http://digitalcommons.unl.edu/natrespapers/196 }}</ref>

==== Examples ====
[[File:Banana farm Chinawal.jpg|thumb|upright|Banana farm at Chinawal village in Jalgaon district, India]]
As of the decade starting in 2010, many hot countries have thriving agricultural sectors.

Jalgaon district, India, has an average temperature which ranges from 20.2&nbsp;°C in December to 29.8&nbsp;°C in May, and an average precipitation of 750&nbsp;mm/year.<ref>{{Cite web|title = Weather statistics for Jalgaon|url = http://www.yr.no/place/india/Maharashtra/Jalgaon/statistics.html|website = yr.no|access-date = 2016-01-27|first = NRK og Meteorologisk|last = institutt}}</ref> It produces bananas at a rate that would make it the world's seventh-largest banana producer if it were a country.<ref>{{cite news|last1=Damodaran|first1=Harish|title=The story of Jalgaon district in Maharashtra as the 'new' banana republic|url=http://indianexpress.com/article/india/india-others/a-different-banana-republic/|newspaper=Indian Express}}</ref>

During the period 1990–2012, Nigeria had an average temperature which ranged from a low of 24.9&nbsp;°C in January to a high of 30.4&nbsp;°C in April.<ref>{{Cite web |title=Climate Change Knowledge Portal 2.0 |url=http://sdwebx.worldbank.org/climateportal/index.cfm?page=country_historical_climate&ThisRegion=Africa&ThisCCode=NGA |publisher=World Bank |access-date=2016-01-27}}</ref> According to the Food and Agriculture Organization of the {{wipe|United Nations}} (FAO), Nigeria is by far the world's largest producer of yams, producing over 38 million tonnes in 2012. The second through 8th largest yam producers were all nearby African countries, with the largest non-African producer, Papua New Guinea, producing less than 1% of Nigerian production.<ref>{{cite web |title=FAOSTAT Agricultural production |url=http://faostat.fao.org/site/339/default.aspx |publisher=Food and Agriculture Association of the United Nations |url-status=dead |archive-url=https://web.archive.org/web/20110713020710/http://faostat.fao.org/site/339/default.aspx |archive-date=13 July 2011}}</ref>

In 2013, according to the FAO, {{wipe|Brazil}} and {{wipe|India}} were by far the world's leading producers of [[Biology:Sugarcane|sugarcane]], with a combined production of over 1 billion tonnes, or over half of worldwide production.<ref name=FAOSTAT>{{cite web |publisher = Food and Agriculture Organization of the United Nations |title=Crop production |url =http://faostat3.fao.org/faostat-gateway/go/to/download/Q/QC/E |access-date=2015-01-27}}</ref>

In the summer of 2018, heat waves probably linked to climate change cause much lower than average yield in many parts of the world, especially in Europe. Depending on conditions during August, more crop failures could rise global food prices.<ref name="This Summer’s Heat Waves Could Be the Strongest Climate Signal Yet">{{cite news |last1=BERWYN |first1=BOB |title=This Summer's Heat Waves Could Be the Strongest Climate Signal Yet |url=https://insideclimatenews.org/news/27072018/summer-2018-heat-wave-wildfires-climate-change-evidence-crops-flooding-deaths-records-broken |access-date=9 August 2018 |agency=Inside Climate News |issue=Climate change |date=28 July 1018}}</ref> losses are compared to those of 1945, the worst harvest in memory.  last year was the third time in four years that global wheat, rice and maize production failed to meet demand, forcing governments and food companies to release stocks from storage. India last week released 50% of its food stocks. Lester Brown, the head of Worldwatch, an independent research organisation, predicted that food prices will rise in the next few months.

According to the UN report "Climate Change and Land: an IPCC special report on climate change, desertification, land degradation, sustainable land management, food security, and greenhouse gas fluxes in terrestrial ecosystems",<ref>{{Cite web|url=https://www.ipcc.ch/srccl/|title=Special Report on Climate Change and Land — IPCC site}}</ref><ref>{{Cite web|url=https://www.nytimes.com/2019/08/08/climate/climate-change-food-supply.html|title=Climate Change Threatens the World’s Food Supply, United Nations Warns|first=Christopher|last=Flavelle|date=8 August 2019|via=NYTimes.com}}</ref> food prices will rise by 80% by 2050 and food shortages are likely to occur. Some authors also suggested that the food shortages will probably affect poorer parts of the world far more than richer ones

To prevent hunger, instability, new waves of climate refugees, international help will be needed to countries who will miss the money to buy enough food and for also for stopping conflicts.<ref name="Heatwave devastates Europe's crops">{{cite news |last1=Vidal |first1=John |last2=Stewart |first2=Heather | name-list-format = vanc |title=Heatwave devastates Europe's crops |url= https://www.theguardian.com/guardianweekly/story/0,12674,1039838,00.html |access-date=9 August 2018 |agency=The Guardian |issue=Climate Change}}</ref><ref name="Conference Fortieth Session">{{cite web |last1=Graziano da Silva |first1=FAO Director-General José |title=Conference Fortieth Session |url=http://www.fao.org/about/who-we-are/director-gen/faodg-statements/detail/en/c/902584/ |website=Food and Agriculture Organization of the United Nations |access-date=9 August 2018}}</ref>(see also [[Earth:Climate change adaptation|Climate change adaptation]]).

At the beginning of the 21 century, floods probably linked to climate change shortened the planting season in the Midwest region in {{wipe|United States}}, what cause damage to the agriculture sector. In May 2019 the floods reduced the projected [[Biology:Maize|corn]] yield from 15 billion bushels to 14.2.<ref>{{cite news |last1=Higgins |first1=Eoin |title=Climate Crisis Brings Historic Delay to Planting Season, Pressuring Farmers and Food Prices |url=https://www.ecowatch.com/climate-crisis-farmers-planting-season-2638398287.html |access-date=30 May 2019 |agency=Ecowatch |date=29 May 2019}}</ref>

===Projections of impacts===
As part of the IPCC's [[Earth:IPCC Fourth Assessment Report|Fourth Assessment Report]], Schneider ''et al.'' (2007) projected the potential future effects of climate change on agriculture.<ref name=tab191>{{cite book | vauthors = Schneider SH | contribution = 19.3.1 Introduction to Table 19.1 | title = Chapter 19: Assessing Key Vulnerabilities and the Risk from Climate Change | series = Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change | url = http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch19s19-3-1.html | veditors = Parry ML | publisher = Print version: CUP. This version: IPCC website | year = 2007 | location = Cambridge University Press (CUP): Cambridge, UK | isbn = 978-0-521-88010-7 | access-date = 2011-05-04 | display-editors = etal | archive-url = https://web.archive.org/web/20130312103028/http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch19s19-3-1.html | archive-date = 12 March 2013 | url-status = dead }}</ref> With low to medium confidence, they concluded that for about a 1 to 3&nbsp;°C global mean temperature increase (by 2100, relative to the 1990–2000 average level) there would be productivity decreases for some cereals in low latitudes, and productivity increases in high latitudes. In the IPCC Fourth Assessment Report, "low confidence" means that a particular finding has about a 2 out of 10 chance of being correct, based on expert judgement. "Medium confidence" has about a 5 out of 10 chance of being correct.<ref name="parry uncertainty assessment">{{cite book | vauthors = Parry ML | contribution = Box TS.2. Communication of uncertainty in the Working Group II Fourth Assessment | title = Technical summary | series = Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change | url = http://www.ipcc.ch/publications_and_data/ar4/wg2/en/tssts-1.html | veditors = Parry ML | publisher = Print version: CUP. This version: IPCC website | year = 2007 | location = Cambridge University Press (CUP): Cambridge, UK | isbn = 978-0-521-88010-7 | access-date = 2011-05-04 | display-editors = etal }}
</ref> Over the same time period, with medium confidence, global production potential was projected to:<ref name=tab191/>
* increase up to around 3&nbsp;°C,
* very likely decrease above about 3&nbsp;°C.

Most of the studies on global agriculture assessed by Schneider ''et al.'' (2007) had not incorporated a number of critical factors, including changes in extreme events, or the spread of pests and diseases. Studies had also not considered the development of specific practices or technologies to aid adaptation to climate change.<ref>{{cite book | vauthors = Schneider SH | contribution = 19.3.2.1 Agriculture | title = Chapter 19: Assessing Key Vulnerabilities and the Risk from Climate Change | series = Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change | url = http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch19s19-3-2-1.html | veditors = Parry ML | publisher = Print version: CUP. This version: IPCC website | year = 2007 | page = 790 | location = Cambridge University Press (CUP): Cambridge, UK | isbn = 978-0-521-88010-7 | access-date = 2011-05-04 | display-editors = etal | archive-url = https://web.archive.org/web/20120819151402/http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch19s19-3-2-1.html | archive-date = 19 August 2012 | url-status = dead }}</ref>

The US National Research Council (US NRC, 2011)<ref name="us nrc 2011 fig 5.1">
[http://www.nap.edu/openbook.php?record_id=12877&page=161 Figure 5.1], p.161, in: Sec 5.1 FOOD PRODUCTION, PRICES, AND HUNGER, in: Ch 5: Impacts in the Next Few Decades and Coming Centuries, in: {{harvnb|US NRC|2011}}
</ref> assessed the literature on the effects of climate change on crop yields. US NRC (2011)<ref name="us nrc 2011 text">
Sec 5.1 FOOD PRODUCTION, PRICES, AND HUNGER, [http://www.nap.edu/openbook.php?record_id=12877&page=160 pp.160-162], in: Ch 5: Impacts in the Next Few Decades and Coming Centuries, in {{harvnb|US NRC|2011}}
</ref> stressed the uncertainties in their projections of changes in crop yields. A meta-analysis in 2014 revealed consensus that yield is expected to decrease in the second half of the century, and with greater effect in tropical than temperate regions.<ref>{{Cite journal|last=Challinor|first=A. J.|last2=Watson|first2=J.|last3=Lobell|first3=D. B.|last4=Howden|first4=S. M.|last5=Smith|first5=D. R.|last6=Chhetri|first6=N.|date=2014|title=A meta-analysis of crop yield under climate change and adaptation|journal=Nature Climate Change|language=en|volume=4|issue=4|pages=287–291|doi=10.1038/nclimate2153|issn=1758-678X|url=http://eprints.whiterose.ac.uk/78340/13/Challinor-etal-AR5-RevisionsFinal_with_coversheet.pdf}}</ref>

Writing in the journal ''Nature Climate Change'', Matthew Smith and Samuel Myers (2018) estimated that food crops could see a reduction of [[Biology:Protein|protein]], [[Chemistry:Iron|iron]] and [[Chemistry:Zinc|zinc]] content in common food crops of 3 to 17%.<ref>{{Cite journal|last=Smith|first=Matthew R.|last2=Myers|first2=Samuel S. | name-list-format = vanc |date=2018-08-27|title=Impact of anthropogenic CO2 emissions on global human nutrition|journal=Nature Climate Change|language=En|volume=8|issue=9|pages=834–839|doi=10.1038/s41558-018-0253-3|issn=1758-678X|bibcode=2018NatCC...8..834S}}</ref> This is the projected result of food grown under the expected atmospheric carbon-dioxide levels of 2050. Using data from the UN Food and Agriculture Organization as well as other public sources, the authors analyzed 225 different staple foods, such as [[Biology:Wheat|wheat]], [[Biology:Rice|rice]], [[Biology:Maize|maize]], vegetables, roots and [[Biology:Fruit|fruit]]s.<ref>{{Cite web|url=https://www.theguardian.com/science/2018/aug/27/climate-change-will-make-hundreds-of-millions-more-people-nutrient-deficient|title=Climate change will make hundreds of millions more people nutrient deficient|last=Davis|first=Nicola| name-list-format = vanc |date=2018-08-27|website=the Guardian|language=en|access-date=2018-08-29}}</ref> The effect of projected for this century levels of atmospheric carbon dioxide on the nutritional quality of plants is not limited only to the above-mentioned crop categories and nutrients. A 2014 meta-analysis has shown that crops and wild plants exposed to elevated carbon dioxide levels at various latitudes have lower density of several minerals such as magnesium, iron, zinc, and potassium.<ref name="eLife 2014">{{Cite journal|last=Loladze|first=Irakli| name-list-format = vanc |date=2014-05-07|title=Hidden shift of the ionome of plants exposed to elevated CO2 depletes minerals at the base of human nutrition| journal=eLife|language=En|volume=3|issue=9|pages=e02245|doi=10.7554/eLife.02245|pmid=24867639|pmc=4034684}}</ref>

{|
| [[File:Projected changes in crop yields at different latitudes with global warming.png|thumb|upright=2|alt=Refer to caption|Projected changes in crop yields at different latitudes with global warming. This graph is based on several studies.<ref name="us nrc 2011 fig 5.1"/>]]
| [[File:Projected changes in yields of selected crops with global warming.png|thumb|upright=2|alt=Refer to caption|Projected changes in yields of selected crops with global warming. This graph is based on several studies.<ref name="us nrc 2011 fig 5.1"/>]]
|}

Their central estimates of changes in crop yields are shown above. Actual changes in yields may be above or below these central estimates.<ref name="us nrc 2011 text"/> US NRC (2011)<ref name="us nrc 2011 fig 5.1"/> also provided an estimated the "likely" range of changes in yields. "Likely" means a greater than 67% chance of being correct, based on expert judgement. The likely ranges are summarized in the image descriptions of the two graphs.

====Food security====

The IPCC Fourth Assessment Report also describes the impact of climate change on [[Earth:Food security|food security]].<ref name="easterling sub saharan africa">{{cite book | vauthors = Easterling WE | contribution = 5.6.5 Food security and vulnerability | title = Chapter 5: Food, Fibre, and Forest Products | series = Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change | url = http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch5s5-6-5.html | veditors = Parry ML | year = 2007 | publisher = Cambridge University Press | isbn = 978-0-521-88010-7 | display-editors = etal | access-date = 25 June 2011 | archive-url = https://web.archive.org/web/20181102224228/http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch5s5-6-5.html | archive-date = 2 November 2018 | url-status = dead }}</ref> Projections suggested that there could be large decreases in [[Philosophy:Hunger|hunger]] globally by 2080, compared to the (then-current) 2006 level.<ref name="easterling food security">
{{cite book | vauthors = Easterling WE | contribution = Executive summary | title = Chapter 5: Food, Fibre, and Forest Products | series = Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change | url = http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch5s5-es.html | veditors = Parry ML | year = 2007 | publisher = Cambridge University Press | isbn = 978-0-521-88010-7 | display-editors = etal }}
</ref> Reductions in hunger were driven by projected [[Social:Social change|social]] and [[Finance:Economic development|economic development]]. For reference, the Food and Agriculture Organization has estimated that in 2006, the number of people undernourished globally was 820 million.<ref>
{{cite web
 | date=30 October 2006
 | title=World hunger increasing
 | publisher=Food and Agriculture Organization (FAO) Newsroom
 | url=http://www.fao.org/newsroom/en/news/2006/1000433/index.html
 | access-date=2011-07-07}}
</ref> Three [[Software:Climate change scenario|scenarios]] ''without'' climate change ([[Earth:Special Report on Emissions Scenarios|SRES]] A1, B1, B2) projected 100-130 million undernourished by the year 2080, while another scenario without climate change (SRES A2) projected 770 million undernourished. Based on an expert assessment of all of the evidence, these projections were thought to have about a 5-in-10 chance of being correct.<ref name="parry uncertainty assessment"/>

The same set of greenhouse gas and socio-economic scenarios were also used in projections that included the effects of climate change.<ref name="easterling food security"/> ''Including'' climate change, three scenarios (SRES A1, B1, B2) projected 100-380 million undernourished by the year 2080, while another scenario with climate change (SRES A2) projected 740–1,300 million undernourished. These projections were thought to have between a 2-in-10 and 5-in-10 chance of being correct.<ref name="parry uncertainty assessment"/>

Projections also suggested regional changes in the global distribution of hunger.<ref name="easterling food security"/> By 2080, [[Place:Sub-Saharan Africa|sub-Saharan Africa]] may overtake [[Earth:Asia|Asia]] as the world's most food-insecure region. This is mainly due to projected social and economic changes, rather than climate change.<ref name="easterling sub saharan africa"/>

In South America, a phenomenon known as the El Nino Oscillation Cycle, between floods and drought on the Pacific Coast has made as much as a 35% difference in Global yields of wheat and grain.<ref>Howden, M. e. (2007). Adapting Agriculture to Climate Change. Proceedings of the National Academy of Sciences of the United States of America 104/50, 19691-19696</ref>

Looking at the four key components of food security we can see the impact climate change has had. "Access to food is largely a matter of household and individual-level income and of capabilities and rights" (Wheeler et al.,2013).  Access has been affected by the thousands of crops being destroyed, how communities are dealing with climate shocks and adapting to climate change. Prices on food will rise due to the shortage of food production due to conditions not being favourable for crop production. Utilization is affected by floods and drought where water resources are contaminated, and the changing temperatures create vicious stages and phases of disease. Availability is affected by the contamination of the crops, as there will be no food process for the products of these crops as a result. Stability is affected through price ranges and future prices as some food sources are becoming scarce due to climate change, so prices will rise.

====Individual studies====

[[File:Projected effect of climate change on agricultural productivity for different regions (Cline, 2007).png|alt=Refer to caption and adjacent text|thumb|upright=2|right|Projections by Cline (2008)<ref name="cline projections"/>]]
Cline (2008)<ref name="cline projections">
{{harvnb|Cline|2008}}
</ref> looked at how climate change might affect agricultural productivity in the 2080s. His study assumes that no efforts are made to reduce anthropogenic greenhouse gas emissions, leading to global warming of 3.3&nbsp;°C above the pre-industrial level. He concluded that global agricultural productivity could be negatively affected by climate change, with the worst effects in developing countries (see graph opposite).

Lobell ''et al.'' (2008a)<ref>
{{harvnb|Lobell|others|2008a}} (paywall). {{harvnb|Lobell|others|2008b}} can be freely accessed.
</ref> assessed how climate change might affect 12 food-insecure regions in 2030. The purpose of their analysis was to assess where adaptation measures to climate change should be prioritized. They found that without sufficient adaptation measures, South Asia and South Africa would likely suffer negative impacts on several crops which are important to large food insecure human populations.

Battisti and Naylor (2009)<ref name="battisti seasonal temp">{{harvnb|Battisti|Naylor|2009}}</ref> looked at how increased seasonal temperatures might affect agricultural productivity. Projections by the IPCC suggest that with climate change, high seasonal temperatures will become widespread, with the likelihood of extreme temperatures increasing through the second half of the 21st century. Battisti and Naylor (2009)<ref name="battisti seasonal temp"/> concluded that such changes could have very serious effects on agriculture, particularly in the tropics. They suggest that major, near-term, investments in adaptation measures could reduce these risks.

"[[Earth:Climate change|Climate change]] merely increases the urgency of reforming trade policies to ensure that global [[Earth:Food security|food security]] needs are met"<ref name="ictsd">[http://ictsd.org/i/press/press-releases/61231/ Ending hunger will require trade policy reform], Press Release, International Centre for Trade and Sustainable Development, 12 October 2009.</ref> said C. Bellmann, ICTSD Programmes Director.  A 2009 ICTSD-IPC study by Jodie Keane<ref name="study">[http://ictsd.org/downloads/2009/10/draft-ictsd-ipc-paper.pdf Climate change, agriculture and aid for trade], by Jodie Keane, ICTSD-IPC</ref> suggests that [[Earth:Climate change|climate change]] could cause farm output in [[Place:Sub-Saharan Africa|sub-Saharan Africa]] to decrease by 12% by 2080 - although in some African countries this figure could be as much as 60%, with agricultural exports declining by up to one fifth in others. Adapting to [[Earth:Climate change|climate change]] could cost the agriculture sector $14bn globally a year, the study finds.

===Regional impacts===

======Africa======
[[File:African crop production.png|thumb|African crop production. Raw data from the United Nations.<ref>{{Cite web|url=http://www.fao.org/faostat/en/|title=FAOSTAT|website=www.fao.org}}</ref>]]
Agriculture is a particularly important sector in Africa, contributing towards livelihoods and economies across the continent. On average, agriculture in Sub-Saharan Africa contributes 15% of the total GDP.<ref name=":2">{{Cite book|title=OECD‑FAO Agricultural Outlook 2016‑2025|last=OECD/FAO|publisher=OECD Publishing|year=2016|isbn=978-92-64-25323-0|url=http://www.fao.org/3/a-i5778e.pdf|pages=59–61}}</ref> Africa's geography makes it particularly vulnerable to climate change, and seventy per cent of the population rely on rain-fed agriculture for their livelihoods. Smallholder farms account for 80% of cultivated lands in sub-Saharan Africa.<ref name=":2" /> The Intergovernmental Panel on Climate Change (IPCC) (2007:13)<ref name="ar4 summary of regional impacts">
{{cite book|title=Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change | veditors = Parry ML, etal |author=IPCC|publisher=Cambridge University Press|year=2007|chapter=Summary for Policymakers: C. Current knowledge about future impacts|chapter-url=http://www.ipcc.ch/publications_and_data/ar4/wg2/en/spmsspm-c.html}}
</ref> projected that climate variability and change would severely compromise agricultural production and access to food. This projection was assigned "high confidence". Cropping systems, livestock and fisheries will be at greater risk of pest and diseases as a result of future climate change.<ref name=":3">{{Cite journal| vauthors = Dhanush D, Bett BK, Boone RB, Grace D, Kinyangi J, Lindahl JF, Mohan CV, Ramírez Villegas J, Robinson TP, Rosenstock TS, Smith J |date=2015|title=Impact of climate change on African agriculture: focus on pests and diseases|url=https://cgspace.cgiar.org/rest/bitstreams/55241/retrieve|journal=CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS)}}</ref> Research program on Climate Change, Agriculture and Food Security (CCAFS) have identified that crop pests already account for approximately 1/6th of farm productivity losses.<ref name=":3" /> Similarly, climate change will accelerate the prevalence of pests and diseases and increase the occurrence of highly impactful events.<ref name=":3" /> The impacts of climate change on agricultural production in Africa will have serious implications for food security and livelihoods. Between 2014 and 2018, Africa had the highest levels of food insecurity in the world.<ref>{{Cite web|url=http://www.fao.org/state-of-food-security-nutrition/en/|title=SOFI 2019 - The State of Food Security and Nutrition in the World|website=www.fao.org|publisher=Food and Agriculture Organization of the United Nations|language=en|access-date=2019-08-08}}</ref>

'''East Africa'''

In East Africa, climate change is anticipated to intensify the frequency and intensity of drought and flooding, which can have an adverse impact on the agricultural sector. Climate change will have varying effects on agricultural production in East Africa.  Research from the International Food Policy Research Institute (IFPRI) suggest an increase in maize yields for most East Africa, but yield losses in parts of Ethiopia, Democratic Republic of Congo (DRC), Tanzania and northern Uganda.<ref>{{Cite web|url=http://www.ifpri.org/publication/east-african-agriculture-and-climate-change-comprehensive-analysis|title=East African agriculture and climate change: A comprehensive analysis |date=2013|website=[[Organization:International Food Policy Research Institute|International Food Policy Research Institute]] (IFPRI)|language=en|access-date=2019-09-21}}</ref> Projections of climate change are also anticipated to reduce the potential of the cultivated land to produce crops of high quantity and quality.<ref>{{Cite book | vauthors = Kurukulasuriya P, Mendelsohn R |title=How Will Climate Change Shift Agro-Ecological Zones And Impact African Agriculture? |date=2008-09-25|publisher=The World Bank|series=Policy Research Working Papers|doi=10.1596/1813-9450-4717|hdl = 10986/6994}}</ref>

In Tanzania there is currently no clear signal in future climate projections for rainfall.<ref name=":4">{{Cite web|url=https://futureclimateafrica.org/resource/future-climate-projections-for-tanzania/|title=Future Climate For Africa|website=Brief: future climate projections for Tanzania|publisher=Future Climate For Africa|language=en|access-date=2019-08-08}}</ref> However, there is a higher likelihood of intense future rainfall events.<ref name=":4" /> As of 2005, the net result was expected to be that 33% less maize—the country's staple crop—would be grown.<ref>{{cite web|url=https://www.theguardian.com/climatechange/story/0,12374,1517935,00.html|title=In the land where life is on hold| first = John | last = Vidal | name-list-format = vanc |date=30 June 2005|website=The Guardian|location=UK|access-date=2008-01-22}}</ref>

'''Southern Africa'''

Climate change will exacerbate the vulnerability of the Agricultural sector in most Southern African countries which are already limited by poor infrastructure and a lag in technological inputs and innovation.<ref>{{cite web |url=https://www.climatelinks.org/sites/default/files/asset/document/2016%20CRM%20Fact%20Sheet%20-%20Southern%20Africa.pdf |title=Fact sheet |website=www.climatelinks.org |format=PDF|access-date=2020-07-12}}</ref> Maize accounts for nearly half of the cultivated land in Southern Africa, and under future climate change, yields could decrease by 30%<ref>{{Cite web|url=http://www.ifpri.org/publication/overview-southern-african-agriculture-and-climate-change|title=Overview [in Southern African Agriculture and Climate Change]|website=www.ifpri.org|access-date=2019-08-08}}</ref> Temperatures increases also encourage a wide spread of weeds and pests<ref>http://cdm15738.contentdm.oclc.org/utils/getfile/collection/p15738coll2/id/127787/filename/127998.pdf</ref> In December 2019, 45 million peoples in southern Africa required help because of crop failure. The drought reduces the water stream in Victoria falls by 50%. The droughts became more frequent in the region.<ref>{{cite news |last1=Rosane |first1=Oivia |title=Victoria Falls Dries Drastically After Worst Drought in a Century |url=https://www.ecowatch.com/victoria-falls-drought-2641553066.htmlOlivia |accessdate=11 December 2019 |agency=Ecowatch |date=9 December 2019}}</ref>

'''West Africa'''

Climate change will significantly affect agriculture in West Africa by increasing the variability in food production, access and availability.<ref>https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20090027893.pdf</ref> The region has already experienced a decrease in rainfall along the coasts of Nigeria, Sierra Leone, Guinea and Liberia.<ref>{{cite web |url= http://ebrary.ifpri.org/utils/getfile/collection/p15738coll2/id/127449/filename/127660.pdf|title= Data |website=ebrary.ifpri.org |format=PDF|access-date=2020-07-12}}</ref> This has resulted in lower crop yield, causing farmers to seek new areas for cultivation.<ref>{{Cite web|url=http://www.fao.org/food-chain-crisis/how-we-work/plant-protection/fallarmyworm/en/|title=Fall Armyworm {{!}} FOOD CHAIN CRISIS {{!}} Food and Agriculture Organization of the United Nations|website=www.fao.org|access-date=2019-08-08}}</ref>  Staple crops such as maize, rice and sorghum will be impacted by low rainfall events with possible increase in food insecurity.<ref>{{Cite book|date=1997|editor-last=Asenso-Okyere|editor-first=W. K.|editor2-last=Benneh|editor2-first=George|editor3-last=Tims|editor3-first=Wouter | name-list-format = vanc |title=Sustainable Food Security in West Africa|language=en-gb|doi=10.1007/978-1-4615-6105-7|isbn=978-1-4613-7797-9}}</ref>

'''Central Africa'''<br />Higher rainfall intensity, prolonged dry spells and high temperatures are expected to negatively impact cassava, maize and bean production in Central Africa.<ref name=":5">{{Cite web|url=https://www.climatelinks.org/file/4614/download?token=rlgPz1eX|title=CLIMATE RISKS IN THE CENTRAL AFRICA REGIONAL PROGRAM FOR THE ENVIRONMENT (CARPE) AND CONGO BASIN|website=Climatelinks}}</ref> Floods and erosion occurrence are expected to damage the already limited transportation infrastructure in the region leading to post harvest losses.<ref name=":5" /> Exportation of economic crops like coffee and cocoa are on the rise within the region but these crops are highly vulnerable to climate change.<ref name=":5" /> Conflicts and political instability have had an impact on agriculture contribution to the regional GDP and this impact will be exacerbated by climatic risks.<ref>{{Cite web|url=https://www.un.org/en/africa/osaa/pdf/pubs/2013africanagricultures.pdf|title=Agriculture in Africa|date=2013|website=United Nations}}</ref>

====Asia====

In [[Place:East Asia|East]] and [[Place:Southeast Asia|Southeast Asia]], IPCC (2007:13)<ref name="ar4 summary of regional impacts"/> projected that [[Earth:Crop yield|crop yield]]s could increase up to 20% by the mid-21st century. In [[Place:Central Asia|Central]] and South Asia, projections suggested that yields might decrease by up to 30%, over the same time period. These projections were assigned "medium confidence." Taken together, the risk of hunger was projected to remain very high in several developing countries.

More detailed analysis of rice yields by the [[Organization:International Rice Research Institute|International Rice Research Institute]] forecast 20% reduction in yields over the region per degree Celsius of temperature rise. Rice becomes sterile if exposed to temperatures above 35 degrees for more than one hour during flowering and consequently produces no grain.<ref>{{Cite journal|last=Singh|first=Saroj Kumar| name-list-format = vanc |date=2016|title=Climate Change: Impact on Indian Agriculture & its Mitigation|journal=Journal of Basic and Applied Engineering Research|volume=3|issue=10|pages=857–859}}</ref><ref>{{Cite book|url=https://books.google.com/books?id=st52DQAAQBAJ&pg=PA330|title=Reconsidering the Impact of Climate Change on Global Water Supply, Use, and Management|last=Rao|first=Prakash|last2=Patil|first2=Yogesh | name-list-format = vanc |publisher=IGI Global|year=2017|isbn=978-1-5225-1047-5|page=330|language=en}}</ref>

A 2013 study by the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) aimed to find science-based, pro-poor approaches and techniques that would enable Asia's agricultural systems to cope with climate change, while benefitting poor and vulnerable farmers. The study's recommendations ranged from improving the use of climate information in local planning and strengthening weather-based agro-advisory services, to stimulating diversification of rural household incomes and providing incentives to farmers to adopt natural resource conservation measures to enhance forest cover, replenish groundwater and use [[Engineering:Renewable energy|renewable energy]].<ref>[http://exploreit.icrisat.org/sites/default/files/uploads/1378286859_PolicyBrief23.pdf ''Vulnerability to Climate Change: Adaptation Strategies and layers of Resilience''], ICRISAT, Policy Brief No. 23, February 2013</ref> A 2014 study found that warming had increased maize yields in the Heilongjiang region of China had increased by between 7 and 17% per decade as a result of rising temperatures.<ref>{{Cite journal | vauthors = Meng Q, Hou P, Lobell DB, Wang H, Cui Z, Zhang F, Chen X | doi = 10.1007/s10584-013-1009-8| title = The benefits of recent warming for maize production in high latitude China| journal = Climatic Change| volume = 122| issue = 1–2| pages = 341–349| year = 2013 | hdl = 10.1007/s10584-013-1009-8| hdl-access = free}}</ref>

Due to climate change, livestock production will be decreased in Bangladesh by diseases, scarcity of forage, heat stress and breeding strategies.<ref>{{Cite journal|last=Chowdhury|first=Q M Monzur Kader | name-list-format = vanc |year=2016|title=Impact of Climate Change on Livestock in Bangladesh: A Review of What We Know and What We Need to Know |url=http://ajaset.e-palli.com/wp-content/uploads/2013/12/IMPACT-OF-CLIMATE-CHANGE-ON-LIVESTOCK-IN-BANGLADESH-A-REVIEW-OF-WHAT-WE-KNOW-AND-WHAT-WE-NEED-TO-KNOW.pdf|journal=American Journal of Agricultural Science Engineering and Technology|volume=3 |issue=2|pages=18–25|via=e-palli}}</ref>

These issues dealing with agriculture are important to consider because countries in Asia rely on this sector for exports for other countries. This in turn contributes to more land degradation to keep up with this global demand which in turn causes cascading environmental effects.{{Citation needed|date=April 2020}} Environmental factor#Socioeconomic Drivers

====Australia and New Zealand====

Hennessy ''et al.''. (2007:509)<ref name="hennessy australia and new zealand">
{{cite book | year = 2007 | chapter = Chapter 11: Australia and New Zealand: Executive summary | title = Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change | veditors = Parry ML | display-editors = etal | publisher = Cambridge University Press | vauthors = Hennessy K | chapter-url = http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch11s11-es.html | display-authors = etal }}
</ref> assessed the literature for {{wipe|Australia}} and [[Earth:New Zealand|New Zealand]]. They concluded that without further adaptation to climate change, projected impacts would likely be substantial: By 2030, production from agriculture and forestry was projected to decline over much of southern and eastern Australia, and over parts of eastern New Zealand; In New Zealand, initial benefits were projected close to major rivers and in western and southern areas. Hennessy ''et al.''. (2007:509)<ref name="hennessy australia and new zealand"/> placed high confidence in these projections.

====Europe====

With high confidence, IPCC (2007:14)<ref name="ar4 summary of regional impacts"/> projected that in [[Place:Southern Europe|Southern Europe]], climate change would reduce crop productivity. In [[Place:Central Europe|Central]] and [[Place:Eastern Europe|Eastern Europe]], forest productivity was expected to decline. In [[Place:Northern Europe|Northern Europe]], the initial effect of climate change was projected to increase crop yields. The 2019 [[Organization:European Environment Agency|European Environment Agency]] report "Climate change adaptation in the agricultural sector in Europe" again confirmed this. According to this 2019 report, projections indicate that yields of non-irrigated crops like wheat, corn and sugar beet would decrease in southern Europe by up to 50% by 2050 (under a high-end emission scenario). This could result in a substantial decrease in farm income by that date. Also farmland values are projected to decrease in parts of southern Europe by more than 80% by 2100, which could result in land abandonment. The trade patterns are also said to be impacted, in turn affecting agricultural income. Also, increased food demand worldwide could exert pressure on food prices in the coming decades.<ref>{{Cite web|url=https://www.eea.europa.eu/highlights/climate-change-threatens-future-of|title=Climate change threatens future of farming in Europe — European Environment Agency|website=www.eea.europa.eu}}</ref>

In 2020, the [[Social:European Union|European Union]]'s Scientific Advice Mechanism published a detailed review of the EU's policies related to the food system, especially the [[Social:Common Agricultural Policy|Common Agricultural Policy]] and the Common Fisheries Policy, in relation to their sustainability.<ref>{{Cite book|last=Science Advice for Policy by European Academies|first=|url=https://www.sapea.info/wp-content/uploads/sustainable-food-system-review.pdf|title=A sustainable food system for the European Union: A systematic review of the European policy ecosystem|publisher=SAPEA|year=2020|isbn=978-3-9820301-7-3|location=Berlin|pages=|doi=10.26356/sustainablefoodreview}}</ref>

====Latin America====

The major agricultural products of Latin American regions include livestock and grains, such as [[Biology:Maize|maize]], [[Biology:Wheat|wheat]], soybeans, and [[Biology:Rice|rice]].<ref name="ref 1">{{cite journal| vauthors = Jones P, Thornton P|title=The potential impacts of climate change on maize production in Africa and Latin America in 2055|journal=Global Environmental Change|date=April 2003|volume=13|issue=1|pages=51–59|doi=10.1016/S0959-3780(02)00090-0}}</ref><ref name="ref 2" /> Increased temperatures and altered hydrological cycles are predicted to translate to shorter growing seasons, overall reduced biomass production, and lower grain yields.<ref name="ref 2">{{cite journal| vauthors = Baethgen WE |title=Vulnerability of the agricultural sector of Latin America to climate change|journal=Climate Research|date=1997|volume=9|pages=1–7|doi=10.3354/cr009001|bibcode=1997ClRes...9....1B|url=https://www.int-res.com/articles/cr/9/c009p001.pdf}}</ref><ref name="ref 3">{{cite journal| vauthors = Mendelsohn R, Dinar A |title=Climate Change, Agriculture, and Developing Countries: Does Adaptation Matter?|journal=The World Bank Research Observer|date=1 August 1999|volume=14|issue=2|pages=277–293|doi=10.1093/wbro/14.2.277}}</ref> {{wipe|Brazil}}, Mexico and {{wipe|Argentina}} alone contribute 70-90% of the total agricultural production in Latin America.<ref name="ref 2"/> In these and other dry regions, maize production is expected to decrease.<ref name="ref 1"/><ref name="ref 2"/> A study summarizing a number of impact studies of climate change on agriculture in Latin America indicated that wheat is expected to decrease in Brazil, Argentina and Uruguay.<ref name="ref 2"/> Livestock, which is the main agricultural product for parts of Argentina, Uruguay, southern Brazil, Venezuela, and Colombia is likely to be reduced.<ref name="ref 1"/><ref name="ref 2"/> Variability in the degree of production decrease among different regions of Latin America is likely.<ref name="ref 1"/> For example, one 2003 study that estimated future maize production in Latin America predicted that by 2055 maize in eastern Brazil will have moderate changes while Venezuela is expected to have drastic decreases.<ref name="ref 1" />

Suggested potential adaptation strategies to mitigate the impacts of global warming on agriculture in Latin America include using plant breeding technologies and installing irrigation infrastructure.<ref name="ref 2" />

===== Climate justice and subsistence farmers in Latin America =====

Several studies that investigated the impacts of climate change on agriculture in Latin America suggest that in the poorer countries of Latin America, agriculture composes the most important economic sector and the primary form of sustenance for small farmers.<ref name="ref 1"/><ref name="ref 2"/><ref name="ref 3"/><ref name="ref 4">{{cite journal | vauthors = Morton JF | title = The impact of climate change on smallholder and subsistence agriculture | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 104 | issue = 50 | pages = 19680–5 | date = December 2007 | pmid = 18077400 | pmc = 2148357 | doi = 10.1073/pnas.0701855104 }}</ref> [[Biology:Maize|Maize]] is the only grain still produced as a sustenance crop on small farms in Latin American nations.<ref name="ref 2"/> Scholars argue that the projected decrease of this grain and other crops will threaten the welfare and the economic development of subsistence communities in Latin America.<ref name="ref 1"/><ref name="ref 2"/><ref name="ref 3"/> Food security is of particular concern to rural areas that have weak or non-existent food markets to rely on in the case food shortages.<ref name="ref 5">{{cite journal |last1=Timmons Roberts |first1=J. |title=The International Dimension of Climate Justice and the Need for International Adaptation Funding |journal=Environmental Justice |date=December 2009 |volume=2 |issue=4 |pages=185–190 |doi=10.1089/env.2009.0029 }}</ref>

According to scholars who considered the environmental justice implications of climate change, the expected impacts of climate change on subsistence farmers in Latin America and other developing regions are unjust for two reasons.<ref name="ref 4"/><ref name="ref 6">{{cite journal |last1=Davies |first1=Mark |last2=Guenther |first2=Bruce |last3=Leavy |first3=Jennifer |last4=Mitchell |first4=Tom |last5=Tanner |first5=Thomas | name-list-format = vanc |title=Climate Change Adaptation, Disaster Risk Reduction and Social Protection: Complementary Roles in Agriculture and Rural Growth? |journal=IDS Working Papers |date=February 2009 |volume=2009 |issue=320 |pages=01–37 |doi=10.1111/j.2040-0209.2009.00320_2.x |url=http://opendocs.ids.ac.uk/opendocs/handle/123456789/2545 }}</ref> First, subsistence farmers in developing countries, including those in Latin America are disproportionately vulnerable to climate change<ref name="ref 6"/> Second, these nations were the least responsible for causing the problem of anthropogenic induced climate.<ref name="ref 6" />

According to researchers John F. Morton and T. Roberts, disproportionate vulnerability to climate disasters is socially determined.<ref name="ref 4"/><ref name="ref 6"/> For example, socioeconomic and policy trends affecting smallholder and subsistence farmers limit their capacity to adapt to change.<ref name="ref 4"/> According to W. Baethgen who studied the vulnerability of Latin American agriculture to climate change, a history of policies and economic dynamics has negatively impacted rural farmers.<ref name="ref 2"/> During the 1950s and through the 1980s, high inflation and appreciated real exchange rates reduced the value of agricultural exports.<ref name="ref 2"/> As a result, farmers in Latin America received lower prices for their products compared to world market prices.<ref name="ref 2"/> Following these outcomes, Latin American policies and national crop programs aimed to stimulate agricultural intensification.<ref name="ref 2"/> These national crop programs benefitted larger commercial farmers more. In the 1980s and 1990s low world market prices for cereals and livestock resulted in decreased agricultural growth and increased rural poverty.<ref name="ref 2"/>

In the book, Fairness in Adaptation to Climate Change, the authors describe the global injustice of climate change between the rich nations of the north, who are the most responsible for global warming and the southern poor countries and minority populations within those countries who are most vulnerable to climate change impacts.<ref name="ref 6"/>

Adaptive planning is challenged by the difficulty of predicting local scale climate change impacts.<ref name="ref 4"/> An expert that considered opportunities for climate change adaptation for rural communities argues that a crucial component to adaptation should include government efforts to lessen the effects of food shortages and famines.<ref name="ref 7">{{cite book |editor-last=Adger |editor-first=Neil |editor2=Jouni Paavola |editor3=Saleemul Huq |display-editors=etal |title=Fairness in adaptation to climate change |date=2006 |publisher=MIT Press |location=Cambridge, MA |isbn=978-0-262-01227-0}}</ref> This researcher also claims that planning for equitable adaptation and agricultural sustainability will require the engagement of farmers in decision making processes.<ref name="ref 7"/>

====North America====
A number of studies have been produced which assess the impacts of climate change on agriculture in [[Earth:North America|North America]]. The IPCC Fourth Assessment Report of agricultural impacts in the region cites 26 different studies.<ref>{{cite book | vauthors = Field CB | contribution=Sec. 14.4.4 Agriculture, forestry and fisheries | title=Chapter 14: North America | series=Climate change 2007: impacts, adaptation and vulnerability: contribution of Working Group II to the fourth assessment report of the Intergovernmental Panel on Climate Change | url=http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch14s14-4-4.html | veditors = Parry ML | year=2007 | publisher=Cambridge University Press | isbn=978-0-521-88010-7 | display-authors=0}}</ref> With high confidence, IPCC (2007:14–15)<ref name="ar4 summary of regional impacts"/> projected that over the first few decades of this century, moderate climate change would increase aggregate yields of rain-fed agriculture by 5–20%, but with important variability among regions. Major challenges were projected for crops that are near the warm end of their suitable range or which depend on highly utilized water resources.

Droughts are becoming more frequent and intense in arid and semiarid western North America as temperatures have been rising, advancing the timing and magnitude of spring snow melt floods and reducing river flow volume in summer.<ref>{{cite web|url=http://www.ncdc.noaa.gov/billions/events|title=Billion-Dollar Weather and Climate Disasters: Table of Events - National Centers for Environmental Information (NCEI)|first=Adam|last=Smith | name-list-format = vanc }}</ref> Direct effects of climate change include increased heat and water stress, altered crop [[Earth:Phenology|phenology]], and disrupted symbiotic interactions. These effects may be exacerbated by climate changes in river flow, and the combined effects are likely to reduce the abundance of native trees in favour of non-native herbaceous and drought-tolerant competitors, reduce the habitat quality for many native animals, and slow litter decomposition and [[Earth:Nutrient|nutrient]] cycling. Climate change effects on human water demand and irrigation may intensify these effects.<ref>{{cite journal|last1= Perry|first1= Laura G.|last2= Andersen|first2= Douglas C.|last3= Reynolds|first3= Lindsay V.|last4= Nelson|first4= S. Mark|last5= Shafroth|first5= Patrick B. | name-list-format = vanc |year=2012 |title=Vulnerability of riparian ecosystems to elevated CO2 and climate change in arid and semiarid western North America |url=http://www.fort.usgs.gov/Products/Publications/23228/23228.pdf |journal=Global Change Biology |volume=18 |issue=3 |pages=821–842 |doi=10.1111/j.1365-2486.2011.02588.x |url-status=dead |archive-url=https://web.archive.org/web/20130526135544/http://www.fort.usgs.gov/Products/Publications/23228/23228.pdf |archive-date=26 May 2013|bibcode= 2012GCBio..18..821P}}</ref>

The US Global Change Research Program (2009) assessed the literature on the impacts of climate change on agriculture in the United States, finding that many crops will benefit from increased atmospheric {{CO2}} concentrations and low levels of warming, but that higher levels of warming will negatively affect growth and yields; that extreme weather events will likely reduce crop yields; that weeds, [[Disease|disease]]s and [[Biology:Insect|insect]] pests will benefit from warming, and will require additional pest and [[Earth:Weed control|weed control]]; and that increasing {{CO2}} concentrations will reduce the land's ability to supply adequate livestock feed, while increased heat, disease, and weather extremes will likely reduce livestock productivity.<ref>{{cite book | author=USGCRP | year=2009 | title=Global Climate Change Impacts in the United States | chapter=Agriculture | veditors = Karl TR, Melillo J, Peterson T, Hassol SJ | publisher=Cambridge University Press | isbn=978-0-521-14407-0 | url=http://www.globalchange.gov/publications/reports/scientific-assessments/us-impacts | chapter-url=http://www.globalchange.gov/publications/reports/scientific-assessments/us-impacts/climate-change-impacts-by-sector/agriculture}}</ref>

====Polar regions====

Anisimov ''et al.''. (2007:655)<ref>{{cite book |year=2007 |chapter=Chapter 15: Polar regions (Arctic and Antarctic): Executive summary | title=Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change | editor=Parry, ML |display-editors=0 |publisher=Cambridge University Press | vauthors = Anisimov OA |chapter-url=http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch15s15-es.html|display-authors=0}}</ref> assessed the literature for the polar region (Arctic and [[Earth:Antarctica|Antarctica]]). With medium confidence, they concluded that the benefits of a less severe climate were dependent on local conditions. One of these benefits was judged to be increased agricultural and forestry opportunities.

''{{wipe|The Guardian}}'' reported on how climate change had affected agriculture in Iceland. Rising temperatures had made the widespread sowing of [[Biology:Barley|barley]] possible, which had been untenable twenty years ago. Some of the warming was due to a local (possibly temporary) effect via ocean currents from the Caribbean, which had also affected fish stocks.<ref>{{cite news |url=https://www.theguardian.com/climatechange/story/0,12374,1517939,00.html |title=Frozen assets |first=Paul |last=Brown | name-list-format = vanc |work=The Guardian |date=30 June 2005 |access-date=2008-01-22}}</ref>

====Small islands====


In a literature assessment, Mimura ''et al.'' (2007:689)<ref>
{{cite book | year = 2007 | chapter = Chapter 16: Small islands: Executive summary | title = Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change | veditors = Parry ML | display-editors = etal | publisher = Cambridge University Press | vauthors = Mimura N | chapter-url = http://www.ipcc.ch/publications_and_data/ar4/wg2/en/ch16s16-es.html | display-authors = etal }}
</ref> concluded that on small islands, subsistence and commercial agriculture would very likely be adversely affected by climate change. This projection was assigned "high confidence."

=== Climate change impacts affecting poverty alleviation===

Researchers at the Overseas Development Institute (ODI) have investigated the potential impacts climate change could have on agriculture, and how this would affect attempts at alleviating poverty in the developing world.<ref name="ccandpoverty"/> They argued that the effects from moderate climate change are likely to be mixed for developing countries. However, the vulnerability of the poor in developing countries to short-term impacts from climate change, notably the increased frequency and severity of adverse weather events is likely to have a negative impact. This, they say, should be taken into account when defining agricultural policy.<ref name="ccandpoverty">{{cite web |url=http://www.odi.org.uk/resources/details.asp?id=1231&title=climate-change-agricultural-policy-poverty-reduction-much-know |title= Climate change, agricultural policy and poverty reduction – how much do we know? |year=2007 |publisher=Overseas Development Institute}}</ref>

=== Crop development models ===

Models for climate behavior are frequently inconclusive. In order to further study effects of global warming on agriculture, other types of models, such as ''crop development models'', ''yield prediction'', quantities of ''water or fertilizer consumed'', can be used. Such models condense the knowledge accumulated of the climate, soil, and effects observed of the results of various agricultural practices. They thus could make it possible to test strategies of adaptation to modifications of the environment.

Because these models are necessarily simplifying natural conditions (often based on the assumption that weeds, disease and insect pests are controlled), it is not clear whether the results they give will have an ''in-field'' reality. However, some results are partly validated with an increasing number of experimental results.

Other models, such as ''insect and disease development'' models based on climate projections are also used (for example simulation of [[Biology:Aphid|aphid]] reproduction or [[Biology:Septoria|septoria]] (cereal fungal disease) development).

Scenarios are used in order to estimate climate changes effects on crop development and yield. Each scenario is defined as a set of meteorological variables, based on generally accepted projections. For example, many models are running simulations based on doubled [[Chemistry:Carbon dioxide|carbon dioxide]] projections, temperatures raise ranging from 1&nbsp;°C up to 5&nbsp;°C, and with rainfall levels an increase or decrease of 20%. Other parameters may include [[Physics:Humidity|humidity]], wind, and solar activity. Scenarios of crop models are testing farm-level adaptation, such as sowing date shift, climate adapted species (vernalisation need, heat and cold resistance), [[Earth:Irrigation|irrigation]] and fertilizer adaptation, resistance to disease. Most developed models are about wheat, maize, rice and [[Biology:Soybean|soybean]].

=== Temperature potential effect on growing period ===

Duration of crop [[Biology:Cell growth|growth]] [[Biology:Biological life cycle|cycles]] are above all, related to temperature. An increase in temperature will speed up development.<ref>{{Cite book|url=https://books.google.com/?id=2qR8Jdrd4EQC&pg=PT33&lpg=PT33&dq=Duration+of+crop+growth+cycles+are+above+all,+related+to+temperature.+An+increase+in+temperature+will+speed+up+development.#v=onepage&q=Duration%20of%20crop%20growth%20cycles%20are%20above%20all,%20related%20to%20temperature.%20An%20increase%20in%20temperature%20will%20speed%20up%20development.&f=false|title=Global Warming: The Causes and Consequences|last=Haldar|first=Ishita| name-list-format = vanc |date=2010-12-23|publisher=Mind Melodies|isbn=9789380302812|language=en}}</ref> In the case of an annual crop, the duration between [[Earth:Sowing|sowing]] and harvesting will shorten (for example, the duration in order to harvest corn could shorten between one and four weeks). The shortening of such a cycle could have an adverse effect on productivity because [[Biology:Senescence|senescence]] would occur sooner.<ref>{{Cite book|url=https://books.google.com/?id=94qdDwAAQBAJ&pg=PA119&dq=The+shortening+of+such+a+cycle+could+have+an+adverse+effect+on+productivity+because+senescence+would+occur#v=onepage&q=The%20shortening%20of%20such%20a%20cycle%20could%20have%20an%20adverse%20effect%20on%20productivity%20because%20senescence%20would%20occur&f=false|title=Effect of High Temperature on Crop Productivity and Metabolism of Macro Molecules|last=Bhattacharya|first=Amitav| name-list-format = vanc |date=2019-06-14|publisher=Academic Press|isbn=9780128176054|language=en}}</ref>

=== Effect of elevated carbon dioxide on crops ===
Elevated atmospheric carbon dioxide affects plants in a variety of ways. Elevated [[Chemistry:Carbon dioxide|CO<sub>2</sub>]] increases crop yields and growth through an increase in photosynthetic rate, and it also decreases water loss as a result of stomatal closing.<ref>{{Cite news|url=https://www.nasa.gov/feature/goddard/2016/nasa-study-rising-carbon-dioxide-levels-will-help-and-hurt-crops|title=Rising Carbon Dioxide Levels Will Help and Hurt Crops|last=Hille|first=Karl| name-list-format = vanc |date=2016-05-03|work=NASA|access-date=2018-11-29|language=en}}</ref> It limits the [[Physics:Vaporization|vaporization]] of water reaching the stem of the plant. [[Biology:Crassulacean acid metabolism|"Crassulacean Acid Metabolism"]] oxygen is all along the layer of the leaves for each plant leaves taking  in CO<sub>2</sub>and release O<sub>2</sub>. The growth response is greatest in [[Biology:C3 carbon fixation|C<sub>3</sub> plants]], [[Biology:C4 carbon fixation|C<sub>4</sub> plants]], <nowiki/>are also enhanced but to a lesser extent, and [[Biology:Crassulacean acid metabolism|CAM Plants]] are the least enhanced species.<ref>{{Cite journal| vauthors = Jongen M, Jones MB |date=1998|title=Effects of Elevated Carbon Dioxide on Plant Biomass Production and Competition in a Simulated Neutral Grassland Community|journal=Annals of Botany|volume=82|issue=1|pages=111–123|jstor=42765089|doi=10.1006/anbo.1998.0654|doi-access=free}}</ref> The stoma in these "CAM plant" stores remain shut all day to reduce exposure. rapidly rising levels of carbon dioxide in the atmosphere affect plants' absorption of nitrogen, which is the nutrient that restricts crop growth in most terrestrial ecosystems. Today's concentration of 400 ppm plants are relatively starved for nutrition. The optimum level of CO2 for plant growth is about 5 times higher. Increased mass of CO2 increases [[Earth:Photosynthesis|photosynthesis]], this CO2 potentially stunts the growth of the plant. It limit's the [[Chemistry:Reduction potential|reduction]] that crops lose through [[Earth:Transpiration|transpiration]].

Increase in global temperatures will cause an increase in evaporation rates and annual evaporation levels. Increased evaporation will lead to an increase in storms in some areas, while leading to accelerated drying of other areas. These storm impacted areas will likely experience increased levels of precipitation and increased flood risks, while areas outside of the storm track will experience less precipitation and increased risk of droughts.<ref>{{Cite web|url=https://pmm.nasa.gov/resources/faq/how-does-climate-change-affect-precipitation|title=How does climate change affect precipitation? {{!}} Precipitation Measurement Missions|website=pmm.nasa.gov|language=en|access-date=2018-11-29}}</ref> Water stress affects plant development and quality in a variety of ways first off drought can cause poor germination and impaired seedling development in plants.<ref>{{cite journal| vauthors = Farooq M, Wahid A, Kobayashi N, Fujita D, Basra SM |date=March 2009 |title=Plant drought stress: effects, mechanisms and management|url=https://www.agronomy-journal.org/articles/agro/abs/2009/01/a7175/a7175.html|journal=Agronomy for Sustainable Development|language=en|volume=29|issue=1|pages=185–212|doi=10.1051/agro:2008021 }}</ref> At the same time plant growth relies on cellular division, cell enlargement, and differentiation. Drought stress impairs mitosis and cell elongation via loss of [[Biology:Turgor pressure|turgor pressure]] which results in poor growth.<ref name=":1">{{cite journal | vauthors = Fahad S, Bajwa AA, Nazir U, Anjum SA, Farooq A, Zohaib A, Sadia S, Nasim W, Adkins S, Saud S, Ihsan MZ, Alharby H, Wu C, Wang D, Huang J | display-authors = 6 | title = Crop Production under Drought and Heat Stress: Plant Responses and Management Options | journal = Frontiers in Plant Science | volume = 8 | pages = 1147 | date = 2017-06-29 | pmid = 28706531 | pmc = 5489704 | doi = 10.3389/fpls.2017.01147 }}</ref> Development of leaves is also dependent upon turgor pressure, concentration of nutrients, and carbon assimilates all of which are reduced by drought conditions, thus drought stress lead to a decrease in leaf size and number.<ref name=":1" /> Plant height, biomass, leaf size and stem girth has been shown to decrease in Maize under water limiting conditions.<ref name=":1" /> Crop yield is also negatively effected by drought stress, the reduction in crop yield results from a decrease in photosynthetic rate, changes in leaf development, and altered allocation of resources all due to drought stress.<ref name=":1" /> Crop plants exposed to drought stress suffer from reductions in leaf water potential and transpiration rate, however [[Biology:Water-use efficiency|water-use efficiency]] has been shown to increase in some crop plants such as wheat while decreasing in others such as potatoes.<ref>{{cite journal | vauthors = Kahiluoto H, Kaseva J, Balek J, Olesen JE, Ruiz-Ramos M, Gobin A, Kersebaum KC, Takáč J, Ruget F, Ferrise R, Bezak P, Capellades G, Dibari C, Mäkinen H, Nendel C, Ventrella D, Rodríguez A, Bindi M, Trnka M | display-authors = 6 | title = Decline in climate resilience of European wheat | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 116 | issue = 1 | pages = 123–128 | date = January 2019 | pmid = 30584094 | pmc = 6320549 | doi = 10.1073/pnas.1804387115 }}</ref><ref>{{cite journal | vauthors = Abbate PE, Dardanelli JL, Cantarero MG, Maturano M, Melchiori RJ, Suero EE |title=Climatic and Water Availability Effects on Water-Use Efficiency in Wheat |journal=Crop Science |date=2004 |volume=44 |issue=2 |pages=474–483 |doi=10.2135/cropsci2004.4740 }}</ref><ref name=":1" /> Plants need water for the uptake of nutrients from the soil, and for the transport of nutrients throughout the plant, drought conditions limit these functions leading to stunted growth. Drought stress also causes a decrease in photosynthetic activity in plants due to the reduction of photosynthetic tissues, stomatal closure, and reduced performance of photosynthetic machinery. This reduction in photosynthetic activity contributes to the reduction in plant growth and yields.<ref name=":1" /> Another factor influencing reduced plant growth and yields include the allocation of resources; following drought stress plants will allocate more resources to roots to aid in water uptake increasing root growth and reducing the growth of other plant parts while decreasing yields.<ref name=":1" />

==== Effect on quality ====
According to the IPCC's TAR, "The importance of climate change impacts on grain and forage quality emerges from new research. Climate change can alter the adequacy ratios for specific macronutrients, carbohydrates and protein.<ref>{{Cite journal|last=Leisner|first=Courtney P.|date=2020-04-01|title=Review: Climate change impacts on food security- focus on perennial cropping systems and nutritional value|url=http://www.sciencedirect.com/science/article/pii/S0168945220300145|journal=Plant Science|language=en|volume=293|pages=110412|doi=10.1016/j.plantsci.2020.110412|issn=0168-9452|doi-access=free}}</ref> For rice, the amylose content of the grain—a major determinant of cooking quality—is increased under elevated CO<sub>2</sub>" (Conroy et al., 1994). Cooked rice grain from plants grown in high-{{CO2}} environments would be firmer than that from today's plants. However, concentrations of iron and zinc, which are important for human nutrition, would be lower (Seneweera and Conroy, 1997). Moreover, the protein content of the grain decreases under combined increases of temperature and CO<sub>2</sub> (Ziska et al., 1997).<ref>[http://www.grida.no/climate/ipcc_tar/wg2/208.htm "Climate Change 2001: Working Group II: Impacts, Adaptation and Vulnerability"] {{webarchive|url=https://web.archive.org/web/20090805194046/http://www.grida.no/climate/ipcc_tar/wg2/208.htm |date=5 August 2009 }} IPCC</ref> Studies using FACE have shown that increases in CO<sub>2</sub> lead to decreased concentrations of micronutrients in crop and non-crop plants with negative consequences for human nutrition,<ref>{{cite journal|doi=10.1016/S0169-5347(02)02587-9|title=Rising atmospheric {{CO2}} and human nutrition: toward globally imbalanced plant stoichiometry?|year=2002| vauthors = Loladze I |journal=Trends in Ecology & Evolution|volume=17|pages=457–461|issue=10}}</ref><ref name="eLife 2014"/> including decreased B vitamins in rice.<ref name="Zhu2018">{{cite journal | vauthors = Zhu C, Kobayashi K, Loladze I, Zhu J, Jiang Q, Xu X, Liu G, Seneweera S, Ebi KL, Drewnowski A, Fukagawa NK, Ziska LH | display-authors = 6 | title = 2) levels this century will alter the protein, micronutrients, and vitamin content of rice grains with potential health consequences for the poorest rice-dependent countries | journal = Science Advances | volume = 4 | issue = 5 | pages = eaaq1012 | date = May 2018 | pmid = 29806023 | pmc = 5966189 | doi = 10.1126/sciadv.aaq1012 }}</ref><ref>{{cite web |url=https://www.sciencenews.org/article/carbon-dioxide-increases-rice-loses-b-vitamins-nutrients |title=As CO2 increases, rice loses B vitamins and other nutrients | first = Susan | last = Milius | name-list-format = vanc |date=23 May 2018 |website=Sciencenews.org |access-date=2 July 2018}}</ref> This may have knock-on effects on other parts of [[Earth:Ecosystem|ecosystem]]s as herbivores will need to eat more food to gain the same amount of protein.<ref>{{cite journal| first1 = Carlos E. | last1 = Coviella | first2 = John T. | last2 = Trumble | name-list-format = vanc |journal=Conservation Biology|volume= 13|issue= 4|year=1999|title=Effects of Elevated Atmospheric Carbon Dioxide on Insect-Plant Interactions|jstor=2641685|pages=700–712|doi=10.1046/j.1523-1739.1999.98267.x}}</ref>

Studies have shown that higher CO<sub>2</sub> levels lead to reduced plant uptake of nitrogen (and a smaller number showing the same for trace elements such as zinc) resulting in crops with lower nutritional value.<ref name="The Food, the Bad, and the Ugly">[http://www.grist.org/news/maindish/2005/07/12/scherer-plantchem/ The Food, the Bad, and the Ugly] ''Scherer, Glenn'' Grist July, 2005</ref><ref>[https://www.newscientist.com/article/mg17623715-200-plague-of-plenty/ Plague of Plenty] New Scientist Archive</ref><ref>[https://www.politico.com/agenda/story/2017/09/13/food-nutrients-carbon-dioxide-000511/ The Great Nutrient Collapse] ''Bottemiller Evich, Helena'' Politico, 2017</ref> This would primarily impact on populations in poorer countries less able to compensate by eating more food, more varied diets, or possibly taking supplements.

Reduced nitrogen content in grazing plants has also been shown to reduce animal productivity in sheep, which depend on microbes in their gut to digest plants, which in turn depend on nitrogen intake.<ref name="The Food, the Bad, and the Ugly"/> Because of the lack of water available to crops in warmer countries they struggle to survive as they suffer from dehydration, taking into account the increasing demand for water outside of agriculture as well as other agricultural demands.<ref>{{Cite web|url=http://eprints.maynoothuniversity.ie/2886/1/JS_Irish_Agriculture.pdf|title=Climate Change and Irish Agriculture}}</ref>

=== Effect of hail ===
In North America, fewer hail days will occur overall due to climate change, but storms with larger hail might become more common (including hail that is larger than 1.6-inch).<ref name=nclimate3321>{{cite journal |last1=Brimelow |first1=Julian C. |last2=Burrows |first2=William R. |last3=Hanesiak |first3=John M. | name-list-format = vanc |title=The changing hail threat over North America in response to anthropogenic climate change |journal=Nature Climate Change |date=26 June 2017 |volume=7 |issue=7 |pages=516–522 |doi=10.1038/nclimate3321 |bibcode=2017NatCC...7..516B }}</ref><ref>{{cite journal | vauthors = Botzen WJ, Bouwer LM, Van den Bergh JC |title=Climate change and hailstorm damage: Empirical evidence and implications for agriculture and insurance |journal=Resource and Energy Economics |date=August 2010 |volume=32 |issue=3 |pages=341–362 |doi=10.1016/j.reseneeco.2009.10.004 }}</ref><ref name=nclimate3321/> Hail that is larger than 1.6-inch can quite easily break (glass) greenhouses.<ref>{{Cite web|url=https://www.theverge.com/2017/6/26/15873162/hailstorms-increase-north-america-climate-change-extreme-weather|title=Bigger hail might pummel the US as climate change gathers more force|first=Alessandra|last=Potenza|date=26 June 2017|website=The Verge}}</ref>

=== Agricultural surfaces and climate changes ===
Climate change may increase the amount of arable land in high-latitude region by reduction of the amount of frozen lands. A 2005 study reports that temperature in Siberia has increased three-degree Celsius in average since 1960 (much more than the rest of the world).<ref>German Research Indicates Warming in Siberia, Global Warming Today, Global Warming Today</ref> However, reports about the impact of global warming on Russian agriculture<ref>Federal Service for Hydrometeorology and Environmental Monitoring 5Roshydromet), Strategic Forecast of Climate Change in the Russian Federation 2010–2015 and Its Impact on Sectors of the Russian Economy (Moscow 2005)</ref> indicate conflicting probable effects: while they expect a northward extension of farmable lands,<ref>{{cite journal |first1=Alexey O. |last1=Kokorin |first2=Inna G. | name-list-format = vanc |year=2007 |last2=Gritsevich |title=The Danger of Climate Change for Russia – Expected Losses and Recommendations |journal=Russian Analytical Digest |issue=23 |pages=2–4 |url=https://ethz.ch/content/dam/ethz/special-interest/gess/cis/center-for-securities-studies/pdfs/RAD-23-2-4.pdf }}</ref> they also warn of possible productivity losses and increased risk of drought.<ref>{{cite news |last1=Pearce |first1=Fred |title=Global warming 'will hurt Russia' |url=https://www.newscientist.com/article/dn4232-global-warming-will-hurt-russia/ |work=New Scientist |date=3 October 2003 }}</ref>

Sea levels are expected to get up to one meter higher by 2100, though this projection is disputed. A rise in the sea level would result in an agricultural [[Earth:Land consumption|land loss]], in particular in areas such as South East Asia. [[Earth:Erosion|Erosion]], [[Earth:Sea level rise|submergence of shorelines]], [[Earth:Salinity|salinity]] of the [[Earth:Water table|water table]] due to the increased sea levels, could mainly affect agriculture through [[Earth:Inundation|inundation]] of low-lying lands.

Low-lying areas such as Bangladesh, India and Vietnam will experience major loss of rice crop if sea levels rise as expected by the end of the century. Vietnam for example relies heavily on its southern tip, where the Mekong Delta lies, for rice planting. Any rise in sea level of no more than a meter will drown several km<sup>2</sup> of rice paddies, rendering Vietnam incapable of producing its main staple and export of rice.<ref>{{cite journal|title=Coping With Climate Change|first=Reiner|last=Wassmann| name-list-format = vanc |journal=Rice Today|publisher=IRRI|date=July–September 2007|pages=10–15|url=http://www.irri.org/publications/today/pdfs/6-3/10-15.pdf |access-date=2009-10-07 |url-status=dead |archive-url=https://web.archive.org/web/20090327094148/http://www.irri.org/publications/today/pdfs/6-3/10-15.pdf |archive-date=27 March 2009 }}</ref>

=== Erosion and fertility ===
The warmer atmospheric temperatures observed over the past decades are expected to lead to a more vigorous hydrological cycle, including more extreme rainfall events.  [[Earth:Erosion|Erosion]] and soil degradation is more likely to occur.  Soil fertility would also be affected by global warming. Increased erosion in agricultural landscapes from anthropogenic factors can occur with losses of up to 22% of soil carbon in 50 years.<ref>{{Cite journal|last=Doetterl|first=Sebastian|last2=Oost|first2=Kristof Van|last3=Six|first3=Johan| name-list-format = vanc |date=2012-05-01|title=Towards constraining the magnitude of global agricultural sediment and soil organic carbon fluxes|journal=Earth Surface Processes and Landforms|language=en|volume=37|issue=6|pages=642–655|doi=10.1002/esp.3198|issn=1096-9837|hdl=2078.1/123112|bibcode=2012ESPL...37..642D}}</ref> However, because the ratio of soil organic carbon to nitrogen is mediated by soil biology such that it maintains a narrow range, a doubling of soil organic carbon is likely to imply a doubling in the storage of [[Chemistry:Nitrogen|nitrogen]] in soils as organic nitrogen, thus providing higher available nutrient levels for plants, supporting higher yield potential. The demand for imported fertilizer nitrogen could decrease, and provide the opportunity for changing costly [[Biology:Fertilisation|fertilisation]] strategies.

Due to the extremes of climate that would result, the increase in precipitations would probably result in greater risks of erosion, whilst at the same time providing soil with better hydration, according to the intensity of the rain. The possible evolution of the [[Chemistry:Organic matter|organic matter]] in the soil is a highly contested issue: while the increase in the temperature would induce a greater rate in the production of minerals, lessening the soil organic matter content, the atmospheric CO<sub>2</sub> concentration would tend to increase it.

=== Potential effects of global climate change on pests, diseases and weeds ===
A very important point to consider is that weeds would undergo the same acceleration of cycle as cultivated crops, and would also benefit from carbonaceous fertilization. Since most weeds are C3 plants, they are likely to compete even more than now against C4 crops such as corn. However, on the other hand, some results make it possible to think that weedkillers could increase in effectiveness with the temperature increase.<ref>{{cite journal |title=Early Summer Weed Control|url=http://extension.unl.edu/statewide/sw3/6.17.15%20Early%20Summer%20Weed%20Control.pdf|journal=-}}</ref>

Global warming would cause an increase in rainfall in some areas, which would lead to an increase of atmospheric humidity and the duration of the wet seasons. Combined with higher temperatures, these could favour the development of [[Biology:Fungi|fungal]] diseases. Similarly, because of higher temperatures and humidity, there could be an increased pressure from insects and [[Biology:Vector (epidemiology)|disease vectors]].

=== Glacier retreat and disappearance ===
The continued [[Biology:Effects of global warming#Glacier retreat and disappearance|retreat of glaciers]] will have a number of different quantitative impacts. In the areas that are heavily dependent on [[Earth:Surface runoff|water runoff]] from glaciers that melt during the warmer summer months, a continuation of the current retreat will eventually deplete the glacial ice and substantially reduce or eliminate runoff. A reduction in runoff will affect the ability to [[Earth:Irrigation|irrigate]] crops and will reduce summer stream flows necessary to keep dams and reservoirs replenished.

Approximately 2.4&nbsp;billion people live in the [[Earth:Drainage basin|drainage basin]] of the Himalayan rivers.<ref>{{cite web | url = http://www.peopleandplanet.net/pdoc.php?id=3024 | title = Big melt threatens millions, says UN | archive-url = https://web.archive.org/web/20080219045312/http://www.peopleandplanet.net/pdoc.php?id=3024 | archive-date = 19 February 2008 | work = People & the Planet }}</ref> {{wipe|India}}, China, {{wipe|Pakistan}}, Afghanistan, Bangladesh, Nepal and Myanmar could experience floods followed by severe droughts in coming decades.<ref>{{cite web |url= http://english.peopledaily.com.cn/90001/90781/90879/6222327.html |work = People's Daily Online | title = Glaciers melting at alarming speed}}</ref> In {{wipe|India}} alone, the Ganges provides water for drinking and farming for more than 500 million people.<ref>{{cite web |url= http://www.rediff.com/news/2007/jul/24indus.htm | title = Ganges, Indus may not survive: climatologists | date = 24 July 2007 | work = Rediff.com India Limited }}</ref><ref>{{cite news|url=http://news.bbc.co.uk/2/hi/science/nature/3998967.stm|title=Himalaya glaciers melt unnoticed|date=10 November 2004|via=bbc.co.uk}}</ref> The west coast of North America, which gets much of its water from glaciers in mountain ranges such as the Rocky Mountains and Sierra Nevada, also would be affected.<ref>{{cite web | url = https://www.sciencedaily.com/releases/2008/03/080317154235.htm | title = Glaciers Are Melting Faster Than Expected, UN Reports | work = ScienceDaily }}</ref>

=== Ozone and UV-B ===
Some scientists think agriculture could be affected by any decrease in stratospheric ozone, which could increase biologically dangerous [[Physics:Ultraviolet|ultraviolet radiation B]]. Excess ultraviolet radiation B can directly affect [[Biology:Plant physiology|plant physiology]] and cause massive amounts of [[Biology:Mutation|mutation]]s, and indirectly through changed [[Biology:Pollinator|pollinator]] behavior, though such changes are not simple to quantify.<ref>{{cite news|last=Brown|first=Paul| name-list-format = vanc |date=26 April 2005|url=https://www.theguardian.com/uk_news/story/0,,1470944,00.html |title=Ozone layer least fragile on record|work=The Guardian}}</ref> However, it has not yet been ascertained whether an increase in greenhouse gases would decrease stratospheric ozone levels.

In addition, a possible effect of rising temperatures is significantly higher levels of [[Earth:Tropospheric ozone|ground-level ozone]], which would substantially lower yields.<ref>{{cite web|first=Michael|last=McCarthy| name-list-format = vanc |date=27 April 2005|title=Climate change poses threat to food supply, scientists say |work=The Independent |url=http://news.independent.co.uk/world/environment/story.jsp?story%3D633349 |access-date=2009-10-07 |url-status=dead |archive-url=https://web.archive.org/web/20050627000215/http://news.independent.co.uk/world/environment/story.jsp?story=633349 |archive-date=27 June 2005}}</ref>

=== ENSO effects on agriculture ===
ENSO (El Niño Southern Oscillation) will affect monsoon patterns more intensely in the future as climate change warms up the ocean's water. Crops that lie on the equatorial belt or under the tropical Walker circulation, such as rice, will be affected by varying monsoon patterns and more unpredictable weather. Scheduled planting and harvesting based on weather patterns will become less effective.

Areas such as Indonesia where the main crop consists of rice will be more vulnerable to the increased intensity of ENSO effects in the future of climate change. University of Washington professor, David Battisti, researched the effects of future ENSO patterns on the Indonesian rice agriculture using [IPCC]'s 2007 annual report<ref>IPCC. Climate Change 2007: Synthesis Report. United Nations Environment Programme, 2007:Ch5, 8, and 10.[http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr.pdf]</ref> and 20 different logistical models mapping out climate factors such as wind pressure, sea-level, and humidity, and found that rice harvest will experience a decrease in yield. Bali and Java, which holds 55% of the rice yields in Indonesia, will be likely to experience 9–10% probably of delayed monsoon patterns, which prolongs the hungry season. Normal planting of rice crops begin in October and harvest by January. However, as climate change affects ENSO and consequently delays planting, harvesting will be late and in drier conditions, resulting in less potential yields.<ref>{{cite journal | vauthors = Naylor RL, Battisti DS, Vimont DJ, Falcon WP, Burke MB | title = Assessing risks of climate variability and climate change for Indonesian rice agriculture | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 104 | issue = 19 | pages = 7752–7 | date = May 2007 | pmid = 17483453 | pmc = 1876519 | doi = 10.1073/pnas.0701825104 | bibcode = 2007PNAS..104.7752N }}</ref>

== Mitigation and adaptation==
{{main|Earth:Climate change mitigation|Earth:Climate change adaptation}}

=== In developed countries ===
Several mitigation measures for use in developed countries have been proposed:
<ref>{{Cite web|url=https://cgspace.cgiar.org/bitstream/handle/10568/71051/SBSTA44-Agricultural-practices-technologies.pdf|title=Climate change adaptation in agriculture: practices and technologies}}</ref>
* breeding more resilient crop varieties, and diversification of crop species
* using improved agroforestry species
* capture and retention of rainfall, and use of improved irrigation practices
* Increasing forest cover and Agroforestry
* use of emerging water harvesting techniques (such as [[Earth:Contour trenching|contour trenching]], ...)

=== In developing countries ===
The Intergovernmental Panel on Climate Change (IPCC) has reported that agriculture is responsible for over a quarter of total global greenhouse gas emissions.<ref name="IPCC">IPCC. 2007. Climate Change 2007: Synthesis Report. Contributions of Working Groups I, Ii, and Iiito the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Geneva:
IPCC</ref> Given that agriculture's share in global [[Finance:Gross domestic product|gross domestic product]] (GDP) is about 4%, these figures suggest that [[Earth:Agriculture|agriculture]] is highly [[Chemistry:Greenhouse gas|greenhouse gas]] intensive. Innovative agricultural practices and technologies can play a role in [[Earth:Climate|climate]] change mitigation<ref name="mitigation">Basak R. 2016. Benefits and costs of climate change mitigation technologies in paddy rice: Focus on Bangladesh and Vietnam. CCAFS Working Paper no. 160. Copenhagen, Denmark: CGIAR Research Program on Climate Change, Agriculture and Food Security (CCAFS). http://cgspace.cgiar.org/rest/bitstreams/79059/retrieve</ref> and [[Earth:Ecosystem-based adaptation|adaptation]]. This adaptation and mitigation potential is nowhere more pronounced than in developing countries where agricultural productivity remains low; poverty, vulnerability and food insecurity remain high; and the direct effects of climate change are expected to be especially harsh. Creating the necessary agricultural technologies and harnessing them to enable developing countries to adapt their agricultural systems to changing climate will require innovations in policy and institutions as well.  In this context, institutions and policies are important at multiple scales.

Travis Lybbert and Daniel Sumner suggest six policy principles:<ref>{{cite journal |last1=Lybbert |first1=Travis J. |last2=Sumner |first2=Daniel A. | name-list-format = vanc |title=Agricultural technologies for climate change in developing countries: Policy options for innovation and technology diffusion |journal=Food Policy |date=February 2012 |volume=37 |issue=1 |pages=114–123 |doi=10.1016/j.foodpol.2011.11.001 }}</ref>
#The best policy and institutional responses will enhance information flows, incentives and flexibility.
#Policies and institutions that promote economic development and reduce poverty will often improve agricultural adaptation and may also pave the way for more effective climate change mitigation through agriculture.
#Business as usual among the world's poor is not adequate.
#Existing technology options must be made more available and accessible without overlooking complementary capacity and investments.
#Adaptation and mitigation in [[Earth:Agriculture|agriculture]] will require local responses, but effective policy responses must also reflect global impacts and inter-linkages.
#[[Social:Trade|Trade]] will play a critical role in both mitigation and adaptation, but will itself be shaped importantly by climate change.

The Agricultural Model Intercomparison and Improvement Project (AgMIP)<ref>{{cite press release |url=https://www.worldscientific.com/page/pressroom/2015-03-10-02 |title=Food for the Future - Assessments of Impacts of Climate Change on Agriculture |publisher=Imperial College Press |date=April 2015 |access-date=17 July 2019 }}</ref> was developed in 2010 to evaluate agricultural models and intercompare their ability to predict climate impacts. In sub-Saharan Africa and South Asia, South America and East Asia, AgMIP regional research teams (RRTs) are conducting integrated assessments to improve understanding of agricultural impacts of climate change (including biophysical and economic impacts) at national and regional scales. Other AgMIP initiatives include global gridded modeling, data and information technology (IT) tool development, simulation of crop pests and diseases, site-based crop-climate sensitivity studies, and aggregation and scaling.

One of the most important projects to mitigate climate change with agriculture and adapting agriculture to climate change at the same time, was launched in 2019 by the "Global EverGreening Alliance". The initiative was announced in the 2019 UN Climate Action Summit. One of the main methods is Agroforestry. Another important method is Conservation farming. One of the targets is to sequester carbon from the atmosphere. By 2050 the restored land should sequestrate 20 billion of carbon annually. The coalition wants, among other, to recover with trees a territory of 5.75 million square kilometres, achieve a health tree - grass balance on a territory of 6.5 million square kilometres and increase carbon capture in a territory of 5 million square kilometres.

The first phase is the "Grand African Savannah Green Up" project. Already millions families implemented these methods, and the average territory covered with trees in the farms in [[Place:Sahel|Sahel]] increased to 16%.<ref>{{cite news |last1=Hoffner |first1=Erik |title=Grand African Savannah Green Up': Major $85 Million Project Announced to Scale up Agroforestry in Africa |url=https://www.ecowatch.com/agroforestry-africa-climate-summit-2641102482.html |accessdate=27 October 2019 |agency=Ecowatch |date=25 October 2019}}</ref>

== Impact of agriculture on climate change ==
[[File:Greenhouse gas emissions from agriculture, by region, 1990-2010.png|thumb|right|upright=2|alt=refer to caption and image description|Greenhouse gas emissions from agriculture, by region, 1990-2010]]
The agricultural sector is a driving force in the gas emissions and land use effects thought to cause climate change. In addition to being a significant user of land and consumer of fossil fuel, agriculture contributes directly to [[Chemistry:Greenhouse gas|greenhouse gas]] emissions through practices such as rice production and the raising of livestock;<ref>{{cite book | vauthors = Steinfeld H, Gerber P, Wassenaar T, Castel V, Rosales M, de Haan C | title = Livestock's long shadow: environmental issues and options | url = http://www.virtualcentre.org/en/library/key_pub/longshad/A0701E00.pdf | publisher = Food and Agriculture Organization of the UN | archive-url = https://web.archive.org/web/20080625012113/http://www.virtualcentre.org/en/library/key_pub/longshad/A0701E00.pdf |archive-date=25 June 2008 | isbn = 978-92-5-105571-7 | date = 2006 }}</ref> according to the [[Organization:Intergovernmental Panel on Climate Change|Intergovernmental Panel on Climate Change]], the three main causes of the increase in greenhouse gases observed over the past 250 years have been fossil fuels, land use, and agriculture.<ref>[http://ipcc-wg1.ucar.edu/wg1/wg1-report.html Intergovernmental Panel on Climate Change] {{webarchive|url=https://web.archive.org/web/20070501031449/http://ipcc-wg1.ucar.edu/wg1/wg1-report.html |date=1 May 2007 }} ([[Organization:Intergovernmental Panel on Climate Change|IPCC]])</ref>

===Land use===

Agriculture contributes to greenhouse gas increases through land use in four main ways:
* CO<sub>2</sub> releases linked to deforestation
* Methane releases from [[Biology:Rice|rice cultivation]]
* Methane releases from [[Biology:Enteric fermentation|enteric fermentation]] in cattle
* [[Chemistry:Nitrous oxide|Nitrous oxide]] releases from [[Chemistry:Fertilizer|fertilizer]] application

Together, these agricultural processes comprise 54% of [[Chemistry:Methane emissions|methane emissions]], roughly 80% of nitrous oxide emissions, and virtually all carbon dioxide emissions tied to land use.<ref>[http://www.grida.no/climate/ipcc/emission/076.htm Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios] retrieved 26 June 2007</ref>

The planet's major changes to [[Earth:Land cover|land cover]] since 1750 have resulted from deforestation in temperate regions: when forests and woodlands are cleared to make room for fields and [[Earth:Pasture|pasture]]s, the [[Earth:Albedo|albedo]] of the affected area increases, which can result in either warming or cooling effects, depending on local conditions.<ref>{{cite web|url=http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-chapter2.pdf|title=Intergovernmental Panel on Climate Change}}</ref> Deforestation also affects regional [[Biology:RuBisCO|carbon reuptake]], which can result in increased concentrations of [[Chemistry:Carbon dioxide|CO<sub>2</sub>]], the dominant greenhouse gas.<ref>[http://www.ipcc.ch/pdf/assessment-report/ar4/wg1/ar4-wg1-ts.pdf IPCC Technical Summary] retrieved 25 June 2007</ref> Land-clearing methods such as slash and burn compound these effects by burning biomatter, which directly releases greenhouse gases and particulate matter such as [[Earth:Soot|soot]] into the air.

=== Livestock ===

Livestock and livestock-related activities such as deforestation and increasingly fuel-intensive farming practices are responsible for over 18%<ref name="lls">{{Cite book|url=https://books.google.com/books?id=1B9LQQkm_qMC|title=Livestock's Long Shadow: Environmental Issues and Options|first1=Henning|last1=Steinfeld|first2=Pierre|last2=Gerber|first3=T. D.|last3=Wassenaar|first4=Vincent|last4=Castel|first5=Cees |last5 = de Haan | name-list-format = vanc |date=1 January 2006|publisher=Food & Agriculture Org.|via=Google Books|url-status=dead|archive-url=https://web.archive.org/web/20080625012113/http://www.virtualcentre.org/en/library/key_pub/longshad/A0701E00.pdf|archive-date=25 June 2008|isbn=9789251055717}},</ref> of human-made greenhouse gas emissions, including:
* 9% of global [[Chemistry:Carbon dioxide|carbon dioxide]] emissions
* 35–40% of global [[Chemistry:Methane|methane]] emissions (chiefly due to [[Biology:Enteric fermentation|enteric fermentation]] and [[Chemistry:Manure|manure]])
* 64% of global nitrous oxide emissions (chiefly due to [[Chemistry:Fertilizer|fertilizer]] use.<ref name="lls"/>)

Livestock activities also contribute disproportionately to land-use effects, since crops such as [[Biology:Maize|corn]] and [[Biology:Alfalfa|alfalfa]] are cultivated in order to feed the animals.

In 2010, [[Biology:Enteric fermentation|enteric fermentation]] accounted for 43% of the total greenhouse gas emissions from all agricultural activity in the world.<ref>Food and Agriculture Organization of the United Nations (2013) [http://www.fao.org/docrep/018/i3107e/i3107e00.htm "FAO STATISTICAL YEARBOOK 2013 World Food and Agriculture"].  See data in Table 49.</ref> The meat from ruminants has a higher carbon equivalent footprint than other meats or vegetarian sources of protein based on a global meta-analysis of lifecycle assessment studies.<ref>{{cite journal |last1=Ripple |first1=William J. |last2=Smith |first2=Pete |last3=Haberl |first3=Helmut |last4=Montzka |first4=Stephen A. |last5=McAlpine |first5=Clive |last6=Boucher |first6=Douglas H. | name-list-format = vanc |title=Ruminants, climate change and climate policy |journal=Nature Climate Change |date=20 December 2013 |volume=4 |issue=1 |pages=2–5 |doi=10.1038/nclimate2081 |bibcode=2014NatCC...4....2R }}</ref> Methane production by animals, principally ruminants, is estimated 15-20% global production of methane.<ref>{{cite journal | vauthors = Cicerone RJ, Oremland RS | title = Biogeochemical aspects of atmospheric methane. | journal = Global Biogeochemical Cycles | date = December 1988 | volume = 2 | issue = 4 | pages = 299–327 | doi = 10.1029/GB002i004p00299 | url = http://www.escholarship.org/uc/item/3xq3t703 | bibcode = 1988GBioC...2..299C }}</ref><ref>{{cite journal | vauthors = Yavitt JB | title = Methane, biogeochemical cycle. | journal = Encyclopedia of Earth System Science | date = 1992 | volume = 3 | pages = 197–207 | location = London, England | publisher = Academic Press }}</ref>

Worldwide, livestock production occupies 70% of all land used for agriculture, or 30% of the land surface of the Earth.<ref name="lls"/> The way livestock is grazed also decides the fertility of the land in the future, not circulating grazing can lead to unhealthy soil and the expansion of livestock farms affects the habitats of local animals and has led to the drop in population of many local species from being displaced.

== See also ==
* [[Earth:Agroecology|Agroecology]]
* [[Earth:Aridification|Aridification]]
* [[Earth:Biochar|Biochar]]
* [[Earth:Climate change and invasive species|Climate change and invasive species]]
* Climate change and meat production
* [[Earth:Climate resilience|Climate resilience]]
* Environmental issues with agriculture
* Fisheries and Climate Change
* [[Earth:Food security|Food security]]
* Global warming and wine
* International Assessment of Agricultural Science and Technology for Development addressing the links between climate change & agriculture
* Land Allocation Decision Support System – a research tool that is used to test how climate change may affect agriculture (e.g. yield and quality)
* [[Unsolved:Malthusian catastrophe|Malthusian catastrophe]]
* [[Earth:Retreat of glaciers since 1850|Retreat of glaciers since 1850]]
* Slash-and-char
* [[Earth:Terra preta|Terra preta]]
* Water crisis

== References ==
{{Reflist}}

== Further reading ==
{{refbegin}}
<!-- The following references are cited using Template:Harvard citation: -->
* {{citation
 |author=Annex I NC 
 |ref=CITEREFAnnex I NC2014 
 |title=6th national communications (NC6) from Parties included in Annex I to the Convention including those that are also Parties to the Kyoto Protocol 
 |url=https://unfccc.int/process-and-meetings/transparency-and-reporting/reporting-and-review-under-the-convention/national-communications-and-biennial-reports-annex-i-parties/national-communication-submissions/sixth-national-communications-annex-i 
 |publisher=United Nations Framework Convention on Climate Change 
 |date=24 October 2014
}}
* {{cite journal | vauthors = Battisti DS, Naylor RL | title = Historical warnings of future food insecurity with unprecedented seasonal heat | journal = Science | volume = 323 | issue = 5911 | pages = 240–4 | date = January 2009 | pmid = 19131626 | doi = 10.1126/science.1164363 | ref = CITEREFBattistiNaylor2009 | url = https://semanticscholar.org/paper/cfe03b0c6c36c948f7f4c5138a1d409f2c903536 }}.
* {{cite magazine
 |date=March 2008 
 |title=Global Warming and Agriculture 
 | vauthors = Cline WR 
 |ref=CITEREFCline2008 
 |magazine=Finance and Development 
 |volume=45 
 |issue=1 
 |url=http://www.imf.org/external/pubs/ft/fandd/2008/03/cline.htm 
 |url-status=live 
 |archive-url=https://web.archive.org/web/20140817114644/http://www.imf.org/external/pubs/ft/fandd/2008/03/cline.htm 
 |archive-date=17 August 2014 
}}. Archived 
* {{citation
 |author=HLPE 
 |ref=CITEREFHLPE2012 
 |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 
 |url-status=bot: unknown 
 |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 
}}. Archived .
* {{citation
 | veditors = Hoffmann U 
 |ref=CITEREFHoffmann2013 
 |title=Trade and Environment Review 2013: Wake up before it is too late: Make agriculture truly sustainable now for food security in a changing climate 
 |journal=Trade and Environment Review 
 |url=http://unctad.org/en/pages/PublicationWebflyer.aspx?publicationid=666 
 |publisher=United Nations Conference on Trade and Development (UNCTAD) 
 |location=Geneva, Switzerland 
 |year=2013 
 |issn=1810-5432 
 |url-status=bot: unknown 
 |archive-url=https://web.archive.org/web/20141128140551/http://unctad.org/en/pages/PublicationWebflyer.aspx?publicationid=666 
 |archive-date=28 November 2014 
}}. Archived .
* {{citation
 | year=2014
 | author=IPCC AR5 WG2 A
 | ref={{harvid|IPCC AR5 WG2 A|2014}}
 | editor=Field, CB | title=Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II (WG2) to the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC)
 | url=http://www.ipcc.ch/report/ar5/wg2/
 | publisher=Cambridge University Press
|display-editors=etal}}. Also available at [https://web.archive.org/web/20141028163549/http://ipcc-wg2.gov/AR5/report/full-report/ IPCC Working Group 2]. Archives: Main IPCC website: [https://web.archive.org/web/20141216153948/http://ipcc.ch/report/ar5/wg2/ 16 December 2014]; IPCC WG2: [https://web.archive.org/web/20141105164634/https://ipcc-wg2.gov/AR5/report/full-report/ 5 November 2014].
* {{citation
 |year=2014 
 |author=IPCC AR5 WG3 
 |ref={{harvid|IPCC AR5 WG3|2014}} 
 |editor=Edenhofer, O. 
 |title=Climate Change 2014: Mitigation of Climate Change. Contribution of Working Group III (WG3) to the Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) 
 |url=http://www.ipcc.ch/report/ar5/wg3/ 
 |publisher=Cambridge University Press 
 |display-editors=etal 
 |url-status=dead 
 |archive-url=https://web.archive.org/web/20141127222605/http://www.ipcc.ch/report/ar5/wg3/ 
 |archive-date=27 November 2014 
}}. Also available at [https://web.archive.org/web/20141230092610/http://mitigation2014.org/report/publication/ mitigation2014.org]. Archives: Main IPCC website: [https://web.archive.org/web/20141127222605/http://www.ipcc.ch/report/ar5/wg3/ 27 November 2014]; mitigation2014.org: [https://web.archive.org/web/20141230092610/http://mitigation2014.org/report/publication/ 30 December 2014].
* {{cite journal | vauthors = Lobell DB, Burke MB, Tebaldi C, Mastrandrea MD, Falcon WP, Naylor RL | title = Prioritizing climate change adaptation needs for food security in 2030 | journal = Science | volume = 319 | issue = 5863 | pages = 607–10 | date = February 2008 | pmid = 18239122 | doi = 10.1126/science.1152339 | ref = CITEREFLobellothers2008a }}
* {{citation
 | year=2008b
 | ref=CITEREFLobellothers2008b
 | title=Prioritizing climate change adaptation needs for food security - Policy Brief
 | publisher=Center on Food Security and the Environment, Stanford University
 | url=http://fse.fsi.stanford.edu/publications/prioritizing_climate_change_adaptation_needs_for_food_security__policy_brief
 | vauthors = Lobell D
|display-authors=0}}. Archived [https://web.archive.org/web/20140927083725/http://fse.fsi.stanford.edu/sites/default/files/science_policy_brief.pdf 27 September 2014.]
* {{citation
 |author=Non-Annex I NC 
 |ref=CITEREFNon-Annex I NC2014 
 |title=Non-Annex I national communications 
 |url=http://unfccc.int/national_reports/non-annex_i_natcom/items/2979.php 
 |publisher=United Nations Framework Convention on Climate Change 
 |date=11 December 2014 
 |url-status=bot: unknown 
 |archive-url=https://web.archive.org/web/20140913171139/http://unfccc.int/national_reports/non-annex_i_natcom/items/2979.php 
 |archive-date=13 September 2014 
}}. Archived .
* {{citation
 |ref=CITEREFUS NRC2011 
 |author=US NRC 
 |year=2011 
 |title=Climate Stabilization Targets: Emissions, Concentrations, and Impacts over Decades to Millennia 
 |url=http://www.nap.edu/catalog.php?record_id=12877 
 |publisher=National Academies Press 
 |location=Washington, D.C., USA 
 |url-status=dead 
 |archive-url=https://web.archive.org/web/20140327000317/http://www.nap.edu/catalog.php?record_id=12877 
 |archive-date=27 March 2014 
|doi=10.17226/12877 
 |isbn=978-0-309-15176-4 
 }}
* {{cite web |title=4) Differences between agricultural and forest land |publisher=Rainforest Conservation Fund |url=http://www.rainforestconservation.org/rainforest-primer/7-special-topics/b-agriculture/4-differences-between-agricultural-and-forest-land/ }}
{{refend}}

== External links ==
* [http://www.fao.org/climatechange/en/ Climate change] on the Food and Agriculture Organization of the United Nations website.
* [http://www.ifpri.org/publication/climate-change-1 Report on the relationship between climate change, agriculture and food security] by the [[Organization:International Food Policy Research Institute|International Food Policy Research Institute]] 
* [http://www.adb.org/features/12-things-know-2012-rice Climate Change, Rice and Asian Agriculture: 12 Things to Know] Asian Development Bank
* [http://www.macaulay.ac.uk/LADSS/climate_change_wshop.html LADSS – Climate Change and Agriculture] – Are we asking the right questions?
* ''The Guardian's'' [https://www.theguardian.com/environment/climate-change climate change coverage] often includes discussions about food security
*"[https://farmingfirst.org/climate_infographic/ A History of Agriculture and Climate Change at the UNFCCC]" infographic
* [http://www.greenfacts.org/en/agriculture-iaastd/index.htm#4 How is climate change threatening agriculture?] section of official popularized version of IAASTD synthesis report (2008)
* [https://web.archive.org/web/20090521091928/http://ec.europa.eu/agriculture/analysis/external/euro_forests/index_en.htm Impacts of Climate Change on European Forests and Options for Adaptation] (2008)
* [http://www.ccafs.cgiar.org/ Climate Change, Agriculture and Food Security] (Consultative Group on International Agricultural Research)

{{Global warming}}
{{DEFAULTSORT:Climate Change And Agriculture}}
[[Category:Climate change]]

{{Sourceattribution|Climate change and agriculture|1}}