As CO2 and other greenhouse gasses (GHGs) continue their upward trend, global warming is expected to intensify. The
IPCC Fourth Assessment Report (2007) found that global warming and the resulting climate change are strongly predicted to lead to an increase in the number and intensity of extreme weather events, such as heavy precipitation, floods, droughts, and hurricanes (
IPCC). Although heavy rains are expected to increase in the moist tropics, water stress is predicted to affect hundreds of millions of people due to the decreased availability of clean, accessible drinking water as well as a decrease in the amount of water available for agriculture (
IPCC). Although it is clear that climate change affects agriculture, climate change is also affected by agriculture, which contributes 13.5 percent of all human-induced greenhouse gas emissions globally (
USGCRP, 2009).
According to the US Global Change Research Program (USGCRP), “Extreme events such as heavy downpours and droughts are likely to reduce crop yields because excesses or deficits of water have negative impacts on plant growth” (
USGCRP, 2009, Agriculture section, 1st text box). For example, a punishing drought in China has put a third of the country’s wheat crop at risk, and since China is the world’s biggest wheat producer, this has put a strain on an already stressed global food supply, which is currently at a record high prices (
FAO, 2011). Excessive rainfall also delays spring planting and flooding during growing season can lead to lower crop yields due to “low oxygen levels in the soil, increased susceptibility to root diseases, and increased soil compaction due to the use of heavy farm equipment on wet soils” (
USGCRP, 2009, Agriculture section, para. 19).
Carbon dioxide levels are expected to continue their global rise and warming is expected to intensify (IPCC, 2007). Although many crops show positive responses to elevated CO2 levels, higher levels of warming negatively affect growth and crop yields (
USGCRP, 2009). For example, even moderate warming has been shown to negatively effect yields of corn, wheat, sorghum, bean, rice, cotton, and peanut crops (
USGCRP). Additionally, higher temperatures cause plants to use more water to keep cool and with increasing demand (due to population growth) and competition among its primary uses (urban, agricultural, and environmental), freshwater supplies needed for these crops have been predicted to become increasingly limited. We have already seen this condition throughout California as competition for water continues to intensify.
The effects of climate change on agriculture are clear, but agriculture also effects climate change. As global population increases, food demand increases. This means that industrial farming, and all of the negative externalities associated with it, is growing at a rapid rate. Beyond all of the
oil and water that goes into maintaining industrial scale farming, genetically modified seeds are now widespread both in the US and globally. This has led to a huge loss in genetic variability and an increase in the use of pesticides, creating superbugs, which in turn results in an even larger increase in pesticide use (note that pesticides, as well as herbicides and fungicides, are products of the petrochemical industry). The loss of genetic variability is also an important issue because genetic variability is what allows organisms to adapt as well as maintain defenses against viruses and bacteria.
Another concern is the deforestation of large tracts of land in order to create space for agriculture. For example, according to
Yale’s Environment 360 (2011), in Ethiopia 400,000 hectares, an area 80 times the size of Manhattan, has been designated as “a huge agricultural investment potential” by the Ethiopian ministry of agriculture, despite a majority of the land being located in a national park and right in the middle of the second largest mammal migration on earth. Most of the concessions are going to Indian agricultural firm Karuturi Global Limited. Along with the new agriculture will come an expected 600 new roads, where there used to be a single dirt road. The large nearby swamp is also being drained for irrigation purposes and locals have complained that ever since the forests were demolished the honeybees have disappeared – honey was a source of food and income for these people, which has now been lost. Moreover, deforestation and draining water reservoirs often lead to increased desertification.
All of these actions, including the oil and GHG emissions associated with agriculture, lead to a further increase in CO2 levels, which lead to increased warming and more intense climate change overall. This in turn leads to lower crop yields, which then leads to more intensive farming practices as well as agricultural expansion… and the positive feedback loop continues.
Carbon dioxide emissions, global warming, world water wars, and agricultural expansion are just a few of the ways that climate change and the global food crisis are interconnected. There are innumerable ways to loop the two issues together simply by reading the news and connecting the dots. Unfortunately, many people apparently lack the skills to make these connections themselves and, sadly, the media is doing a terrible job at pointing out the connections between the emerging global food crisis and global climate change. Hopefully this recognition will come sooner rather than later, and more importantly,
I hope that it is not already to late to make this recognition.
Works Cited:
FAO, Food and Agriculture Organization of the United Nations. (2011, March 03). Tight cereal markets as food prices increase again. Retrieved from:
http://www.fao.org/news/story/en/item/51913/icode/
Pearce, F. (2011, March 07). Agribusiness Boom Threatens Key African Wildlife Migration. Yale Environment 360. Online via:
http://e360.yale.edu/feature/agribusiness_boom_threatens_key_african_wildlife_migration/2377/
USGCRP, US Global Change Research Program. (2009). Global Climate Change Impacts in the United States, Thomas R. Karl, Jerry M. Melillo, and Thomas C. Peterson, (eds.). Cambridge University Press. Available online at:
http://globalchange.gov/publications/reports/scientific-assessments/us-impacts/download-the-report
IPCC, Intergovernmental Panel on Climate Change. (2007). Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M.Tignor and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA
