Effects Of Climate Change On Crops example essay topic

Global Warming - Its Implications on the Human Population Though there is some scepticism that climate change is a result of human actions, it is unlikely to be a natural event. Some dismiss the phenomenon known as "global warming" as a hoax, and claim that yuppies driving SUVs could not possibly change the overall temperature of the earth. In a sense, this misguided notion is true- but climate change is much more than "yuppies driving SUVs". It is industry freely burning fossil fuels to make a profit, and about the fact that every person on the earth requires energy, a clean source for which does not yet exist, or has not been implemented because of the tight grip governments and corporations hold on their stake in energy (fossil fuels), on which they know every person is dependant. Nine of the eleven hottest years in the 20th century have occurred since 1985, which is not consistent with a natural trend [Haines et al., 1998].

Glacier shrinkage is occurring at a much faster rate than can be explained by natural trends [Oerlermans, 1994]. Even when the heat effects of volcanoes and other misleading weather phenomena that would make the temperature of the earth seem higher than it actually is are taken out of consideration, studies show that the surface temperature of the earth has been increasing at a rate of 0.17 degrees Celsius per decade [Haines et al., 1998]. These figures are not consistent with a natural trend, and, when one considers the tens of thousands of years in which humans have inhabited the earth, and that humans have really only started burning fossil fuels heavily since the industrial revolution, and the fact that the world's population is only going to increase, this number is dauntingly enormous. Increased carbon dioxide in the atmosphere may alter the surface temperature through the "greenhouse" effect, which is capable of changing the ground terrain, from melting glaciers to expanding tropics and savannahs toward higher latitudes. These altered environmental states change the living conditions of microbial vectors (organisms and animals) that transmit diseases, and will lead to specific health problems, ranging from increases in infectious diseases to problems due to heat stress, among others. With many countries edging toward greenhouse gas emission constraints, it clear that any restrictions that are put forth must balance the needs of the environment with the needs of industry.

Unfortunately, any restrictions implemented will hurt many economies, the only question is which countries will it pose a threat to, and by how much. The decrease in global demand for fossil fuels due to a "carbon tax" aimed at reducing emissions in a particular country, will result in a significant drop in their prices, resulting in economic gains for fossil-fuel importers, and losses for fossil-fuel exporters [Bernstein et al., 1999]. Depending on the carbon tax and the carbon intensity of the product, reduce international competitiveness. In energy-intensive industries, such as chemicals, steel, or cement, mitigating countries will suffer, to a point where an importing country will import from a country who has chosen not to implement any such carbon tax. This only hinders the efforts made by those who have made emission restrictions, as the environment is none the better, and the country that had good intentions is now poorer. This scenario is known as "leakage", where industries in emission-restricted countries suffer at the gain of non-complying countries, and thus gives few such exporting countries the incentive to improve the state of the earth.

This makes it clear that sub-global abatement of emission restrictions will nullify the efforts of those who are working towards greenhouse gas emission control. Though many countries claim to be working towards emission control, their good efforts are quite questionable when one factors in such flexible instruments as emissions trading. Simply put, emissions trading consists of a major polluting country buying "emission credits" from a country that does not meet their limit. The rules regarding this practice in the Kyoto Protocol are vague and few, and from this we see that the negative impacts of any emission-controls on a country are minimal, though it undermines the efforts of international emission control agreements. One important aspect of the Kyoto Protocol effort is the unwillingness of the USA to make any emission control commitments. The stance set by the USA will render the Kyoto Protocol ineffective, as it has been observed that the US accounts for one-quarter of the world's greenhouse emissions.

Without emission constraint, the US economy is more or less unaffected by carbon abatement policies of the committed countries. The higher fossil-fuel demand of the US economy has important implications for the rest of the world. Non-compliance by the US will result in the maintenance of coal and oil prices, which would otherwise drop. This will be beneficial to those countries that depend on fossil fuel exports, i.e. OPEC countries, and will have a negative effect on those countries who depend on energy imports, such as Europe and Japan, as well as developing regions, such as China and India, and will have an even greater effect on those countries who are both energy importers and signed Kyoto Protocol countries. Before the November 1997 Kyoto Protocol, large sectors of the U.S. industry waged an intense and well-funded campaign against international regulation of greenhouse gas emissions. Recently, however, there has been a shift in mindset towards this issue by many large US corporations, but many environmentalists doubt their sincerity.

The reasons for this are simply that first, by doing so, that corporation can gain huge rewards in public recognition, and thus gain ties with politicians and policymakers that allow them to conduct business in a manner that best suits them. Secondly, the simple fact that despite the intimidating nature of the Kyoto Protocol on an industry, the fact is, the targets and goals set forth in it are very lax, and more and more it seems to be just an effort by a few countries to quash concerns from scientists and environmental groups about the deteriorating state of the earth, with no significant hurt to big business around the world. Levy [2001] reports that greenhouse gas emissions need to be slashed by more than 50% to stabilize the earth's climate; the Kyoto Protocol calls for a 5% decrease in world greenhouse gas emissions, and this meagre target is fast becoming unreachable. Initiatives aimed at reducing the world's greenhouse gas emissions by shrinking industries, implementing a "carbon tax" and other such attempts do not take into account the effects they will have on the people that depend on these industries for their livelihood. It can be shown that, to lower one's income, even indirectly by the economic impacts a carbon tax would have, is to decrease one's ability to access the basic requirements of life, including healthcare. Though many large companies and corporations may experience declines in annual profits, it is certain that if environmental initiatives are made toward decelerating climate change in North America, many workers will lose their jobs, and many will work for less, as a result of shrinking industry production and the loss of revenue North American companies will face, as a result of goods being imported from non-abating countries.

The economic losses to a particular country, therefore, must be balanced with the interests of the environment. Global warming impacts human health through weather disasters, heat stress, land and water scarcity, nutritional health, non-infectious diseases and infectious diseases. One such effect is the acceleration of the global water cycle, resulting in more frequent and more severe weather disasters. According to Epstein [1999] the 1998 summer floods in China were responsible for 3700 deaths, displaced 223 million people, and caused $30 billion in damages. In the Chicago heat wave of 1995, there were 514 deaths in the one hottest month; 485 of these were in the week of the most intense heat.

Sixty percent of patients admitted for heat stress required mechanical ventilation for an average of five days. Whitman el al., 1997]. Weather disasters, primarily in un-developed countries leads to a loss of living space and food availability, and eventually leading to droplet-spread and water-borne disease epidemics. The weather disaster losses for the world during 1998 were $89 billion, which ellipse d the losses of $55 billion for the entire decade of the 1980's [Epstein, 1999].

Since 1976, the World Health Organization has reported that 30 diseases have appeared that are new to medicine [WHO, 1996]. There has also been a reappearance of old diseases previously though to have been controlled. These include malaria, dengue, cholera, rodent-borne viruses, and other diseases that rely on animals or water as vehicles. Climate change would change our ecology with respect to biodiversity, nutrient cycle, physical relocation, internal defence systems, and transmission dynamics within microbes. Increased carbon dioxide levels stimulates microbes and carriers [Epstein, 1999]. Atmospheric ozone depletion may exacerbate the effect of global warming on infectious diseases.

UV light has been shown to cause immunosuppression in both animals and humans, according to studies [Path et al., 1996]. Physical relocation of diseases is known to occur with weather changes and disasters. Mosquito-borne diseases are highly sensitive to climate changes in their geographic range, resulting in increased reproduction, biting rates, and a shortened pathogen incubation period. In the summer of 1999, New York City experienced and outbreak of West Nile Fever and Encephalitis that resulted in seven deaths and over sixty cases reported.

Most of the survivors of West Nile Fever have neurological sequelae. One of the more important mosquito-borne diseases is malaria, currently on the rise, and a significant threat partly due to its drug resistance. Forty-five percent of the world represents a potential malaria transmission zone; global warming could increase this number to sixty percent [McMichael and Haines, 1997]. Algae and Vibrio Cholerae thrive with increased carbon dioxide, nitrogen, and warmer environments [Epstein et al., 1993]. When algae is present, Vibrio cholerae adhere to algae, and revert to an infectious state which is otherwise suppressed without algae.

Because of extensive consumption of fish and contaminated drinking water, Vibrio cholerae spreads rapidly and results in the disease known as cholera. The largest reported cholera outbreak was in 1994 in Rwanda, killing over 40,000 people. Peru had associated economic losses with close to $800 million in seafood exports and $250 million in tourism losses, all secondary to the disease [Epstein, 1999]. Pulmonary disease is also prominent during warming. The pulmonary aspects of global warming appear as increased levels of aero-allergens. Altered concentrations of aero allergens, i.e. spores and moulds, as well as air-pollutants, such as ozone, are produced by the photochemical reactions that are sensitive to temperature [Em berlin, 1994].

The heat generated by global warming has been shown to increase levels of allergens, especially pollen [Ziska and Caulfield, 2000]. An increase of allergens is associated with rising levels of asthma, especially during the first three years of a child's life [Wah n et al., 1997]. Pollutant gases are directly linked to worsening pulmonary health. Von Muti us [2000] reports that a study from Germany revealed increases in the prevalence of bronchitis and chronic cough, correlating with individual exposure to ozone, among other pollutant gases. Both psychiatric and neurological cases have been associated with global warming and weather change. According to Krug et al.

[1998], a study of weather disasters illustrated a 14% increase in suicide rates after natural disasters. Global warming tends to produce a series of disasters, with a compounding effect, and this effect on the human population has not been well studied. De matte et al. [1998] also reports other psycho neurological findings, with include delirium, lethargy, disorientation, and seizures, as shown in the Chicago heat wave.

The medical effects of climate change that pertain to occupational hazards centre around workers both indoors and outdoors. Wu et al. [1996] demonstrated the connection between a hot working environment and human disease by the analysis of human antibodies produced in response to heat shock proteins. According to the National institute of Occupational safety and Health (NIOSH), heat stress is present in working environments in which there is excessive temperatures, humidity, sunlight, and workloads, In such an environment, heat rash, heat syncope, heat cramps, heat exhaustion, and heat stroke occurs due to these harsh working conditions. Unfortunately, the countries in which this problem is of any significance to, and poses any future threat to, are underdeveloped countries, or low-wage workers in developed countries. The impacts of climate change will also be great on those countries more dependant on primary sector economic activities, as there exists a large uncertainty on productivity in the primary sectors.

Global warming has been a major topic of environmental concern over the past several decades. The International Panel on Climate Change (IPCC) has recently predicted a 1 to 3.5 degree Celsius increase in average atmospheric temperature above 1990 levels by the year 2100. Although this temperature increase may seem small, even an increase or decrease of a few degrees in atmospheric temperature is capable of causing drastic alterations in the agricultural process, among many other everyday issues. Though many studies have been done on the probable effects of an increase in global mean temperature, much is still unknown or only guessed at, due to a general lack of deeper understanding of Earth's very complex climate system. Theses impacts include reduction in water availability, in already water-stressed areas, changes in the incidences of extreme weather events, such as typhoons and droughts, and the impacts of the rising sea-level on low-lying areas [Watson et al., 1996].

The effects of factors such as climate variability, water availability, and quality of adaptive response by farmers to the changing climate cannot be determined conclusively. This results in a rather wide range of variability in predictions of global warming effects on Earth's various regions. Even specific temperature and precipitation changes cannot be determined, as they will most likely vary greatly from region to region. Modern agriculture has made an attempt to counteract these obstacles, through irrigation, the substitution of labour through energy-intensive practices, as well as plant-breeding for heat and water-stress tolerant crops.

This adaptation requires initiatives by individual farmers or companies, and financing, which is often difficult to come by. Agronomic research indicates that higher temperatures associated with global warming will be harmful to many crops. Where there is water stress or heat stress, or a combination of the two, many crops will be extremely vulnerable to even slight changes in temperature. Lal et al., [1998] notes that this will affect the rice yields of the largest grain producing areas of the Asian sub-continent. Much of what is said about the effects of climate change on crops proves to be very misleading. For instance, research has shown that, while keeping precipitation and water availability constant, with a 1-2 degree Celsius increase in temperature, grain yields should actually increase.

This situation is reversed if the increase is any greater than 2 degrees, however. The difficulty lies in the fact that water availability is predicted to decrease in many areas with climate change, and precipitation is predicted to be much less constant, which will have a negative effect on crops. Many conclude that climate change will be beneficial in some areas and will have a negative effect in others. This, alone, however does not prove to be a complete answer to the question ion of how will climate change affect the world's crops. Reilly et al.

[1996] indicates that climate change will have a negative effect on crop productivity and yields on those countries situated in the tropics, while beneficial to those countries in higher latitudes, such as those in Europe. Thus the prediction of whether or not global warming will affect a country with respect to agriculture, and if so, by how much, is dependant on the geographical region in which the country is situated, the importance of agriculture to a country's annual income, as well as the particular crops that constitute the bulk of its agricultural earnings. Table 1: Impact of climate change on a range of cereal crops for selected regions Sources: adapted from Reilly et al. (1996). The most important factor in the success or failure of a harvest is a sufficiently moist soil during the growing season. A global increase in atmospheric temperatures most probably will cause a general increase in the frequency and duration of droughts and heavy rains, both damaging to agricultural crops.

Extended droughts, such as the massive drought of the 1930's known as the "Dust Bowl", have throughout history been the causes of massive crop failures. As the Earth's temperature continues to rise, water supply problems will become more and more of an issue. Increased water evaporation, caused by the higher spring and summer temperatures, will most likely result in dryer soils in many areas currently accustomed to more precipitation. As America's cultivated lands grow dryer and dryer, farmers will be forced to increase their usage of irrigation as a means of providing their crops with the proper growing environment. However, an expected increased general demand on water supplies due to the changing climate will make less water available to farmers for irrigation. The mixture of crops and livestock grown and raised in a given region is influenced strongly by the area's climatic conditions and the amount of water available.

The warming of our climate will cause farmers to shift to crops and livestock now found in more southern locations. As the climate warms, farmers' flexibility in crop distribution is very much decreased. Another possible effect of the climate shift we are currently experiencing is an expansion of the ranges of crop destroying pests. The increased vulnerability of crops to these pests could result in greater pesticide use. Other factors that may threaten agriculture in some areas are increased heat stress, more frequent flooding, and salinization of soils caused by rising of sea levels.

Not all of the effects of global warming appear to be negative ones, however, despite the barrage of predicted woes. In many colder areas, for example, warmer temperatures would lengthen the growing season. Northern countries such as Canada and Russia, along with the more northern areas of the United States, should reap the rewards of longer growing seasons. Several studies have shown that, while some regions will suffer agriculturally, America's nationwide food production will not decline substantially.

In fact, recent assessments suggest that the beneficial effects of climate change would probably offset the adverse ones in America's general agricultural production. A 1995 study conducted by the USDA concluded that even a three to five degree Celsius warming of the atmosphere shouldn't effect America's agricultural production significantly. Even the very thing that is the main cause of global warming could be beneficial to agriculture. The higher carbon dioxide levels in the atmosphere should increase the efficiency with which plants use water, possibly offsetting some of the adverse effects of dryer soils. Higher levels of carbon dioxide also have a fertilizing effect that would enable plants to grow more rapidly.

A carbon dioxide concentration of 550 ppm (parts per million) could increase crop yields in some areas by thirty to forty percent. Along with the possible positive effects of increased carbon dioxide concentration, warmer temperatures would make it profitable to cultivate new land, which could result in a. 2 to 1.2 percent increase in agricultural production. Adequate adaptations by farmers are vital in order for global and United States agricultural production to keep pace with the changing climate. The increased climate variability, however, is already, and probably will continue, making adaptations by farmers more difficult, as many are not sure what to expect in the coming years. Altering crops, growing seasons, and fertilizer use to fit the changing climate are keys to maintaining current crop yields.

Agricultural research establishments can promote increased farm productivity and reduced environmental damages through technical progress as well.