The Impact of Global Warming on Agriculture in USA - Research Paper Example

The Impact of Global Warming on Agriculture in USA Number Climate change and agriculture are twodeeply entwined processes which take place in a global magnitude. There exist a plethora of impacts climate change can effect on agriculture. Climate change can have both devastating and beneficial effects on crop growth and quality, livestock health and pests with global warming significantly affecting conditions which impact agriculture such as temperature, carbon IV oxide, glacial run off, precipitation and the interaction of these elements. Negative impacts of global warming on agriculture, health and environment far outweigh any positives. Agriculture is an important sector of the U.S economy. Apart from providing food, the crops, livestock and seafood as a result of agricultural practices yield a minimum of 200 billion US dollars annually to the economy (Cline, 2007). The overall effect of global warming on agriculture will depend on the balance and interaction of these effects. The conditions impacted by global warming decide the carrying capacity of the biosphere to produce enough food for the human population and animals – domesticated and otherwise. It is essential therefore that the world, including the United States, continues to assess the effects global warming may have on agriculture so that proper anticipation and adapted agriculture can be employed to maximize agricultural production. Also, of keen note is that agriculture itself can impact global warming which in turn impacts agriculture back (Cline, 2007). For instance, agricultural practices can release greenhouse gases such as carbon IV oxide, methane and nitrous oxide which alter global warming while agriculture can also change the earth’s land cover which affects the earth’s ability to absorb/ reflect heat and light hence facilitating radiative forcing. Nitrous oxide emissions account for about 60% of the total emissions from the agricultural sector. Nitrous oxide is produced in soils microbially via nitrification and de-nitrification. Ammonium produces nitrates during nitrification whereas nitrates are reduced to nitrogen gas in de-nitrification with the intermediate step in both processes yielding nitrous oxide. In addition, large increase in the application of nitrogenous fertilizer on crops like corn in the United States and other parts of the globe has also increased nitrous oxide emission. In addition, agricultural land use practices such as deforestation, desertification and the use of fossil fuels are major sources of carbon IV oxide with agriculture itself a major contributor to soaring methane and nitrous oxide levels on the earth (Haugen, Musser & Lovelace, 2010). Global warming, as is clearly demonstrated in the United States, can have both negative and positive impacts on agriculture. This paper attempts to highlight some of the effects global warming has had in the United States’ agriculture over time. The United States agricultural system embraces the production of a variety of crops which each have an optimal temperature for vegetative growth where plants thrive. According to experts, temperatures in the United States will rise on average by about 1.2 degrees Celsius by 2040, with carbon IV oxide levels up more than 15% 9growing seasons are predicted to get longer and use more water hence). An increase or decrease in temperature consequently causes a reduction in crop yields. Corn, for example, a common farm produce in the USA, fails to thrive/ reproduce at temperatures beyond 95 degrees Fahrenheit while soybean suffers above 102 degrees Fahrenheit (Cline, 2007). Since pollen and seeds are sensitive to slight temperature changes, crops such as corn and rice continue to decline. Heat sensitive fruits and vegetables such as tomatoes have also suffered. High ozone levels that come with climate change also significantly reduce yields of soybean, wheat and peanut in the Midwest. Ozone levels in the USA have risen steadily in the last century especially in the eastern and Midwestern regions. The United States which is the world’s largest producer of soybeans and corn has seen a considerable decrease in their production rates as result of global warming (Cline, 2007). Increased temperatures also causes stress on livestock with stifling heat demonstrated to lead to livestock reproduction declines as well as loss of appetite. With livestock eating only about half of normal food quantities, decreased appetites thus prolongs the amount of time needed for livestock to attain the desired weight. Heat stress also results in decreased reproduction rates, increased disease incidences and fighting especially among animals in confinement, and even death. Global warming has had, in the United States, therefore, a negative overall impact upon livestock. Americans consume more than 37 million tons of meat annually with the U.S livestock industry producing close to 100 billion dollars worth of produce in 2002 alone. Heat stress affects animals both directly and indirectly resulting in disease, reduced fertility and reduced milk production. Insect parasites and diseases also become more prolific as global warming progresses. Therefore it is predicted that new diseases may spread to the southeast, for example, from tropical areas. The earlier onset of spring and warmer winters could also allow some parasites and pathogens to survive more easily, moisture-dependent pathogens, such as Escherichia coli and Salmonella typhi, could also thrive in increased rainfall – to the detriment of agriculture. In addition, in as much as increase in carbon IV oxide concentration results in increased pastures, studies indicate that these pastures would be of low quality. As a result, livestock would need to eat more to get the same nutritional benefits or farmers would have to supply such feeds with extra supplements, making agriculture in the US quite costly (Maslin, 2002). It is also believed that livestock immunity deteriorates with adverse changes in temperature and so animals can not fight diseases without the use of costly medicines - an added agricultural cost. In addition, drought and such effects of global warming would mean little feed and grazing pastures for livestock in stressed soils that cannot keep up with plant growth. This has detrimental effects on livestock production. For animals that rely on grain, variations in crop production because of drought can become a problem (Johansen, 2002). Despite technological advances that farmers in the United States (such as in Virginia) have embraced in the wake of global warming such as the use of improved/ tolerant/ resistant crop varieties, genetically modified organisms and sophisticated irrigation systems, global warming and climate change still quite comfortably impacts farming productivity, soli properties, natural communities and so on. A study published in science suggests that because of climate change, the USA could lose more than 30% of its main crop, maize, by 2030 (Mendelsohn & Nordhaus, 1994). A number of scientists continue to foretell an incessant increase in temperature throughout the United States in the coming years. If temperatures continue to increase, cooler areas of the country will consequently become more agriculturally productive and open for farming of some of the main food crops in the United States – thus increasing the areas in which certain crops would be grown or moving their ranges north. For instance, this global warming could mean more conducive conditions for the growth of citrus from its current range in Florida to other areas of the southeast. However, in the areas where temperature is already optimum, increase in global warming could mean heat stress or increased disease incidences and thus reduced yields. If temperature change reduces the amount of productive land, total yields could decrease (Rosenberg & Edmonds, 2005). There is also the fear of extreme weather that arises from global warming such as heat waves, drought, strong winds and heavy rains which may be detrimental to crops. With increased global warming, the strengths of hurricanes continue to increase along with the length of the hurricane season. Droughts are responsible for some of the famines experienced in drier parts of the United States with heat waves also causing stress to crops thus limiting yields especially if they occur at certain times of the plants’ life cycles (pollination, pod, fruit set). If not counteracted by irrigation, heat stress can result in wilted plants as a result of increased transpiration rates which causes yield loses. Farmers in the United States have generally therefore had to incur additional cost of irrigation in order to reap anything from their farms. Strong winds which result from global warming can cause leaf and limb damages in plants as well as sandblasting of the soil against the foliage. In addition, most plants cannot withstand extended waterlogged conditions that come as a result of heavy rains/ flooding. These heavy rains can also be detrimental on soil structure (which means lower yields) while also eroding the fertile top soil resulting in irreversible habitat damage (Wyman, 1991). In 2008, for example, the Mississippi River flooded just before harvest period for many crops causing an approximated loss of 8 billion dollars for farmers. On the brighter side, however, many scientists see an increase in carbon IV oxide concentration as a plus in agriculture whereby increase in carbon IV oxide means increase in plant production since carbon IV oxide is an essential raw material during photosynthesis. However, while crops are expected to respond to the increases in carbon IV oxide concentrations positively, other destructive plants such as weeds are highly likely to respond in a similar fashion. In the United States generally, weeds have since become more prolific invading more habitats as global warming increases. At the moment, farmers in the United States are coughing a staggering 9 billion dollars per year in fighting weeds. The ranges of weeds and pests are likely to expand northwards which would cause new problems for farmers’ crops formerly unexposed to this species. In addition, increased pesticide and fungicide use may negatively affect human health. Research work in Duke University demonstrates increased toxicity in poison ivy with increased carbon IV oxide concentrations. Similar studies show that increased carbon IV oxide levels in the environment means herbicides become less effective meaning a higher rate of herbicides will be necessary to achieve the same levels of control (Conway & Pretty, 2013). In the central Great Plains, in the States reputed for their grassy prairies and sprawling row crops, trees and large shrubs have now become common place. In the southwest, perennial grasses have been largely pushed out by mesquite bushes and the invasive kudzu vine (only recently a nuisance to the south only) has steadily spread northwards stretching from Connecticut to Illinois which has retarded agricultural production in these areas. In turn, high quality pastureland once ideal for livestock grazing has become poor-quality brush as farmland faces competition for space. Insect pests in the United States, some of which harbor plant diseases, have become more prolific and widespread as temperatures increase. Increases in temperature, moisture and carbon IV oxide have since resulted in higher populations of destructive pests. Global warming can either see to increased precipitation or decreased rainfall. In drier areas with little transpiration, plants have dried and farmers lost their produce to drought. However, in areas such as in the southeastern United States, rainfall has increased by about 10% over the last century as a result of global warming – positive news for agriculture (Conway & Pretty, 2013). As per data released in 2007, American fisheries, per annum, catch and harvest about 5 metric tons of fish which contributes more than 1.4 billion US dollars to the economy each year. However, with the fisheries already facing several threats such as overfishing and water pollution, global warming has additionally crept in to cause a myriad of other concerns. For instance, a number of marine species have particular temperature ranges at which they thrive. A fluctuation in temperature would see many fish and shell fish species ranges change. The cod in the North Atlantic, for instance, thrives at temperatures below 54 degrees Fahrenheit beyond which reproduction is retarded and survival chances minimized greatly. Many aquatic species therefore migrate to colder waters or move northwards along the coast or in the ocean. Apart from reducing the annual catch, this migration that is facilitated by global warming also sees the migrating fish moving into competition for food and other resources on the new areas which have already been inhabited. Moreover, in warm waters, diseases of aquatic species such as fish become more prevalent. In Southern New England, for example, lobster catches have dramatically declined as a result of temperature sensitive bacterial shell disease. These changes in the temperature also impact the timing of reproduction and fish migrations. In the Northwest, warmer temperatures have affected the lifecycle of salmon and also increased the likelihood of aquatic diseases. These effects are further forecasted to cause untold declines in salmon populations (Cline, 1992). Further still, as a result of global warming, the world’s oceans are growing more acidic because of increases in carbon IV oxide. This increased acidity harms shellfish by weakening their calcium shells which are vulnerable in acidic conditions. In addition, this acidification facilitated by global warming threatens the structures of sensitive ecosystems upon which plenty of fish and shellfish rely (Wyman, 1991). Global warming is additionally responsible for the increased incidences of sea level rises that have been so widespread along the coasts of the United States especially in the last two decades. These increased sea levels have been a doing of the melting of the glaciers and increased precipitation rates all around America as a result of global warming. Increase in sea levels as a result of global warming has resulted in the consumption of land previously allocated to agricultural work. This consequently means there is an ever increasing shortage in the amount of land available for farming all around the coasts of the United States – which results in poorer yields overall as time goes by. In addition, these rises in sea levels have led to incessant inundations in rice paddies with ocean salt waters which damages crops and results in wanting harvests. Melting glaciers also provide additional waters for irrigation and livestock drinking while also availing new lands for agriculture (Cline, 1992). References Cline, W. R. (1992). The economics of global warming. Washington, DC: Institute for International Economics. Cline, W. R. (2007). Global warming and agriculture impact estimates by country. Washington, DC: Center for Global Development :. Cline, W. R. (2007). Global warming and agriculture end-of-century estimates by country. Washington, D.C.: Institute for International Economics ;. Conway, G. R., & Pretty, J. N. (2013). Unwelcome Harvest Agriculture and pollution.. Hoboken: Taylor and Francis. Haugen, D. M., Musser, S., & Lovelace, K. (2010). Global warming. Detroit: Greenhaven Press. Johansen, B. E. (2002). The global warming desk reference. Westport, Conn.: Greenwood Press. Maslin, M. (2002). Global warming. Stillwater, MN: Voyageur Press. Mendelsohn, R., & Nordhaus, W. D. (1994). The impact of global warming on agriculture: a ricardian analysis. Taipei: The Institute of Economics, Academia Sinica. Rosenberg, N. J., & Edmonds, J. (2005). Climate change impacts for the conterminous USA an integrated assessment. Dordrecht, the Netherlands: Springer. Wyman, R. L. (1991). Global climate change and life on earth. New York: Routledge, Chapman, and Hall. Read More