Monday, May 16, 2011

Agriculture and the Environment: The Effects on Climate Change (Not Global Warming)

Ever since agriculture began about 10,000 years ago, it has been a central part of life for human beings. In this day and age, agriculture is more important than ever as the global population grows in concurrence with global hunger. Governments recognize this and often put policies in place in order to better serve the farmers who grow our food. These subsidies, however, while making food cheap, only serve to hurt us and the environment in the long run. The government is footing the bill for environmental degradation by externalizing the cost of environmental damage. Externalizing the cost simply means that the price of the environmental damage isn’t reflected in the price paid for the product. Farmers use pesticides and herbicides, overuse water, and grow more and more crops because it is much cheaper for them to do so than to utilize conservative and/or environmentally friendly practices. These all contribute to climate change, soil degradation and erosion, and water scarcity. While all of these are serious environmental concerns, it is climate change that is the most alarming.

Climate change is not global warming. Global warming is an “average increase in the temperature of the atmosphere near the Earth's surface and in the troposphere, which can contribute to changes in global climate patterns. Global warming can occur from a variety of causes, both natural and human induced. In common usage, ‘global warming’ often refers to the warming that can occur as a result of increased emissions of greenhouse gases from human activities”. This is different from climate change because “climate change refers to any significant change in measures of climate (such as temperature, precipitation, or wind) lasting for an extended period (decades or longer)”. While these terms are often used interchangeably, they both exemplify different meanings. However, they are both caused by the same things because invariably if global warming is occurring, climate change is occurring as well. “Global warming can be likened to sitting in a car in the sun. The sun’s heat enters through the windshield but is unable to escape the same way because it has changed to longer heat wavelengths that cannot penetrate the glass. So, inside the car it gets hotter and hotter. The Earth’s atmosphere creates the same effect; and as we continue to increase the amount of polluting carbon dioxide in the atmosphere, it has the same result as rolling up the windows in a hot car - less and less heat is able to escape”.

The warming of the earth right now is happening at an increased rate that upsets the equilibrium of ecosystems, which are not able to keep up with the increased rate of change, compared to past instances where global warming has naturally occurred. Climate has always varied in the past, however, the change occurred at a slower rate and because of that, ecosystems were able to adapt easier. For example, if the climate is changing slowly, a forest will move in relation to the changing climate. Part of the forest will die where it could grow before as the climate makes it uninhabitable for the forest. However, the forest will then grow where it could not grow before because the climate has now become habitable. Overall, the forest stays the same size. If the climate is changing rapidly, the forest will not be able to adapt and migrate in relation to the changing climate fast enough, which will have detrimental affects on the forest and the organisms living in it.

The increased rate of climate change is due to anthropogenic causes; the addition of greenhouse gases into the air continually traps more and more heat in the atmosphere. Carbon dioxide is the most significant greenhouse gas in our atmosphere right now as it is as it is the most abundant greenhouse gas in the atmosphere with 384 ppm. The United States alone puts more than 10 billion tons of carbon dioxide into the atmosphere every year. Other greenhouse gases play an important role in global warming as well; methane (which is roughly twenty-five times more effective at trapping heat in the atmosphere than carbon dioxide), nitrous oxides, and hydroflourocarbons are all detrimental in their role as greenhouse gases and are put into the atmosphere as a result of human activity at an alarming rate. Since 1750, methane emissions in the atmosphere have increased by 148 percent and nitrous oxide emissions have increased by 18 percent. “Through our combustion of fossil fuels in cars, aircraft, power plants, and factories, we have raised the amount of carbon dioxide in the environment by well over one-third since the start of the Industrial Revolution”. Methane is released into the atmosphere largely by the decomposition of waste in landfills and gas produced by livestock. Livestock produce nearly ten million tons of methane each year.

Animal agriculture is the major contributor of greenhouse gas emissions in the agricultural sector in multiple ways. Animal agriculture contributes to carbon dioxide in the atmosphere due to forests being cleared for livestock grazing. These forests are usually burned, which releases carbon dioxide into the atmosphere. Not only is the carbon dioxide released into the air, but the forest is no longer available to be a carbon sink, or absorb carbon from the atmosphere as vegetation grows. Livestock also takes ten times the amount of energy to produce as grains, as livestock are a trophic level above grains. This, therefore, increases the amount of fossil fuels used to create the final product. Fuel is used to grow and ship the grains to the livestock, which then are made into meat products and shipped to grocery stores. This results in a large amount of carbon dioxide and methane in the atmosphere, as well as other pollutants. In fact, a 2006 report done by the United Nations found that the meat industry produces more greenhouse gases than all the SUVs, cars, trucks, planes, and ships in the world combined. Due to the rising global world population and the likely increased demand for protein in developing and impoverished countries, animal agriculture will continue to expand and release even more methane into the atmosphere. This is supported by findings from the Environmental Protection Agency; between 1990 and 2007, the amount of methane produced by livestock increased from 133.2 TgCO2 Equivalents to 139.0 TgCO2 Equivalents. This trend is likely to continue and increase dramatically over the next few decades.

The main problem with agriculture being a major contributor to climate change is that it, in turn, is affected negatively by climate change. Dry areas become wet, warm areas become cool, wet areas become dry, and cool areas become warm. Certain crops need certain climates in order to thrive well enough to be produced commercially. If the climate rapidly changes, as it is now, a multitude of crops will die due to their inability to keep up with the rapidly changing habitat. This will be devastating to the agricultural industry and global population economically as there will be a decrease in food supply, which means prices will rise. It will also mean that global hunger rates will sharply increase. Farmers will either have to switch to growing different crops and change their whole operation (different crops constitute different methods of growing and harvesting), or they will have to move their operations entirely to a place where their crops will be able to grow. Feedback loops only serve to intensify the problems of global warming. As the global temperature rises, the oceans will become warmer and absorb less carbon dioxide, making increasing the rate at which global warming occurs. The continuation of deforestation would equal less carbon sinks and the rising temperatures would make remaining forests less effective at absorbing carbon dioxide, thus again increasing the rate of global warming. The reduction of ice caps as a result of the increased temperature would also lead to more carbon dioxide in the atmosphere. Ice reflects the sun’s rays at the same wavelength that it enters the atmosphere which allows the radiation to exit the Earth’s atmosphere, as opposed to it hitting the terra firma or ocean, which changes the wavelength and causes it to become trapped in the Earth’s atmosphere. These feedback loops, along with others, play off each other and create a snowball rolling down a hill effect. As they progress further along, the process intensifies and cannot be stopped.

Erosion is the movement of soil by water, wind, or gravity. This process does occur naturally, however, agriculture is increasing the rate at which it is happening. Soil erosion is becoming a major problem throughout the world as the global demand for food increases. Soil is more than just dirt; it “a mixture of minerals, air, water, and organic materials, such as roots, decaying plant parts, fungi, earthworms, bacteria, and microorganisms”. When crops are planted, they take nutrients and moisture out of the soil. When these crops are harvested and the nutrients are not placed back into the soil, degradation can occur if the process repeats itself over the years. The amount of arable land in the world to use for farming is decreasing as conventional farm methods and animal agriculture degrade the soil, often causing desertification. Desertification is when the soil is degraded to the point where it resembles desert sand due to the loss of nutrients and moisture. A famous example of this is the Dust Bowl that occurred in the 1930’s in the United States.

While desertification is not a problem in the United States any longer, it is still a major problem in developing and impoverished countries which do not have the knowledge or technology to prevent desertification. The United States is not, however, immune to soil erosion and degradation. “In this century alone, for instance, the US has lost half its topsoil (the fertile upper layer of earth necessary to grow all food). Around the world, about 70 percent of the land used for agriculture is at risk of being turned to degraded waster soil that will be worthless for farming, unable to sustain healthy and diverse flora, and unlikely to recover. “Currently, the average rate of soil erosion on U.S. cropland is 7 tons per acre per year”. Deforestation is a major cause of soil erosion and desertification. “The immediate consequences of deforestation can be severe. Forests play a crucial role in the natural water cycle, for example. Rain falls in mountain forests, gradually seeps through sand, soil and rock, and emerges from this natural filtration system as clear river and lake water. When the trees are removed, the water simply runs off mountainsides in sheets taking topsoil and rock with it, and leading to soil erosion. Roughly 34 million acres of forests are lost each year. Imagine a forest one hundred miles wide and five hundred miles long - an area greater than the size of New York state - lost every year”.

“About 2 million ha of soil, equivalent to 15 percent of the Earth’s land area (an area larger than the United States and Mexico combined), have been degraded through human activities”. “Causes of soil degradation include overgrazing (35 percent), deforestation (30 percent), agricultural activities (27 percent), over-exploitation of vegetation (7 percent), and industrial activities (1 percent)”. According to these statistics, agriculture accounts for roughly 99 percent of all soil erosion. Once again, animal agriculture is the major contributor as deforestation and overgrazing account for 65 percent of soil degradation. In developing and impoverished countries, forests are cleared for livestock to graze. Instead of managing these grazing lands, the farmers allow the livestock to overgraze, leaving little but dirt. The process is then repeated, resulting in forests and land being cleared and overgrazed, respectively, over and over.

Vegetable production, however, is very degrading to soil quality as well. Vegetable production is one of the most concentrated businesses in industrial agriculture because all of the plants are tightly packed together to increase yield per acre. The vegetables all compete for nutrients and water in the soil, and when there are that many vegetables extremely close together; most of them are left without any real nutritional content due to a severe lack of nutrients in the soil. After these vegetables are harvested, the soil is extremely vulnerable to erosion as it lacks nutrients and water moisture. Since soil formation is a very slow process, even a slight amount of soil degradation can be devastating. “Since 1950, about one-third of American cropped land has had to be abandoned because of erosion problems.” “Soil removed by erosion contains about 3 times more nutrients and 1.5 to 5 times more organic matter than the soil that remains behind”. Once an area is degraded or goes through desertification, it takes many years for any vegetation to be able to grow there again. The soil left behind is often extremely inefficient at sustaining healthy crops and fauna and is a major problem all around the world.

Water scarcity is a growing concern in global politics and it is predicted the next major war will be fought over water. Agriculture only serves to enhance this global tension over water as agriculture enhances the scarcity of water in a plethora of ways. Water is taken for agricultural purposes and no effort is made to replenish it. Water pollution and depletion are by-products of agriculture and cause severe water scarcity. Water pollution from agriculture occurs when soil, pesticides, herbicides, fertilizers, or animal run-off get into the waterways. Soil erosion also plays a large part in water pollution. “In addition to removing valuable soil from farmland, erosion pollutes waterways with sediment. Runoff containing sediment degrades aquatic ecosystems by reducing stream depth and increasing turbidity (making water cloudier), causing the population of fish and other aquatic organisms to decline. According to the EPA, sediment is the most significant non-point source (NPS) pollutant in the US”. A non-point source pollutant is something that is not intentionally directed to waterways, but ends up there regardless.

Pesticides and herbicides also have negative affects on waterways. “The US Department of Agriculture reports that perhaps half the groundwater and well water in the US is, or could be, contaminated by pesticides. When the US Geological Survey conducted its National Water Quality Assessment they found that more than 95% percent of the samples collected from streams were contaminated with pesticide”. As pesticides are carcinogenic, pesticides in the water harm aquatic species and land species. Animal waste, largely coming from Concentrated Animal Feeding Operations (CAFOs), is held in lagoons mixed with water. These lagoons often leak into underground water sources or overflow during storms. Livestock manure has a lot of ammonia in it which is fatal to fish and can be converted into nitrates; elevated nitrates in the drinking water is highly poisonous to humans. Animal waste also has a high level of pathogens and microorganisms which can harm humans and other animals. Heavy metals are also present in animal waste, which contaminates water further and damages organisms that drink the contaminated water and that live in it. Fertilizers can seep into the water and cause eutrophication due to an overabundance of nutrients in the water. Eutrophication is when algal blooms expand at an increased rate and absorb all of the oxygen in the immediate area, which kills all of the aerobic organisms in the water. The algae itself then dies out as well due to a lack of oxygen. What is left is a barren aquatic environment lacking any aerobic organisms.

Another way agriculture contributes to global water scarcity is water depletion. Water is heavily subsidized by government for agriculture in the United States, so farmers use flood irrigation methods, which essentially is just flooding the field of crops. Roughly 75 percent of this water evaporates before it has time to reach the roots of the crops or is lost as run-off. Only about 4 to 8 percent of the water actually goes to the roots of the crops. The rest of it seeps into the ground but does not make contact with the roots of the crops. The largest aquifer in the United States, the Ogallala aquifer, is being depleted at a rate of 12 billion cubic meters per year. Agriculture utilizes roughly 70 percent of the world’s water and its overall use is increasing. The most striking example of water exploitation for agriculture is the Aral Sea; heavy extraction for irrigation of cash crops has “literally drained the lake of life. Since 1960 the lake has shrunk to one-third of its previous area, a loss of 18,500 square miles”. “Because industrial production for the global food market often promotes crops inappropriate to local climate and soil, such agriculture can have devastating impacts on local ecological balance. Aquifers are overdrawn, rivers and lakes are depleted, and soil can be seriously degraded. All water contains some salt. The massive irrigation required by industrial agriculture, especially in inappropriate climates, can leave damaging salt residue. The soil progressively degrades and eventually is made unusable for farming. About 20 percent of the world’s farmland is affected by rising salinity, and about 2.5 million acres are abandoned each year as a result”. All of these negative affects to the environment are connected and linked together - they are not separated by anything.

Despite all the negative affects agriculture currently has on the environment, there are solutions in order to make agriculture a sustainable process while still feeding the global population. Reducing or ideally, eliminating, the consumption of meat, practicing conservative farming methods, eliminating agricultural subsidies, and making the switch to local, organic farms would do wonders for the environment.
Cutting meat consumption alone would drastically reduce the detrimental environmental effects caused by agriculture. “If Americans were to reduce meat consumption by just 20 percent it would be as if we all switched from a standard sedan - a Camry, say - to the ultra-efficient Prius”. Soil erosion, deforestation, pollution of water and air, and climate change would all be slowed as a result of the reduction of the amount of meat eaten. Animal agriculture by itself is one of the most harmful practices to the environment today and the elimination of animal agriculture would dramatically increase the viability of the environment. However, animal agriculture is not going to go away any time soon and more realistic solutions must be put into place. Locally and organically raised livestock reduces the amount of fossil fuels used for transportation, reduces the amount of chemical fertilizers (the animal’s manure is used in its place), and reduces the amount of greenhouse gases released as only a certain number of livestock can be produced viably in the given amount of land. While this solution would have Americans eating less meat, it is a sacrifice that must be made to save the environment. As long as there is animal agriculture, the environment can never be safe.

Eliminating subsidies for agriculture would also serve to reduce the amount of meat consumed, as well as provide incentives for farmers to use conservative and environmentally sustainable practices. If the price of the environmental degradation was reflected in the price of the product (water and air pollution, soil degradation, and greenhouse gas emissions), the cost of meat would be too high for most to eat it every day in the United States, which is currently the common practice. Not only would meat be more expensive, but crops produced by conventional agriculture, and products linked to those crops, would also be more expensive as pesticides, herbicides, fertilizers, fossil fuels, and water would not be subsidized. Farmers would have the incentive to keep their crops viable without pesticides and herbicides. They would also have the incentive to install drip-irrigation systems instead of using flood-irrigation. Drip-irrigation systems consist of a network of pipes that deliver water, drip-by-drip, to the roots of crops, reducing the amount of water used and wasted by an astronomical amount. The removal of fossil fuel subsidies, along with the others, would encourage the growth of local, organic farms to reduce transportation costs and chemical fertilizer costs. This would cause pollution, greenhouse gas emissions, and soil erosion caused by agriculture to decrease considerably as organic farming does not use chemical pesticides, fertilizers, or herbicides. Organic farms also seek to reduce soil erosion by contour farming, which plants crops in furrows along lines of consistent elevation on sloped land in order to prevent soil erosion and slow the movement of water.

While agriculture is harmful to the environment at the present time, there is the possibility of salvation in the removal of agriculture subsidies, reduction of meat consumption, the movement towards local, organic farms, and practicing conservative agriculture methods. All these solutions would serve the reverse the damage agriculture has cause the environment in a staggering way. Climate change has the potential to cause the most harm to the environment, and this is what we need to address first and foremost. Fortunately, however, addressing this issue will also address the other issues as well. Nothing in the environment comes individually wrapped and packaged for human convenience. Harming one thing invariably harms another and benefiting one thing benefits another; the environment is interconnected in ways we cannot even comprehend completely or foresee. The only difference is whether we put in place practices that harm or benefit the environment.

Sources:
M. Borders and H. Sterling Burnett. "Farm Subsidies: Devastating the World's Poor and the Environment". NCPA, 2006.
http://www.epa.gov/climatechange/basicinfo.html
Ibid
Hossay, Patrick. Unsustainable. London & New York: Zed Books, 2006.
http://www.globalissues.org/article/233/climate-change-and-global-warming-introduction#Rapidchangesinglobaltemperature
H. Shugart, R. Sedjo, and B. Sohnjen. “Forests and Global Climate Change”. 2003.
http://www.skepticalscience.com/CO2-is-not-the-only-driver-of-climate.html
Hossay, Patrick. Unsustainable. London & New York: Zed Books, 2006.
EPA, Frequently Asked Questions About Global Warming and Climate Change: Back to Basics, page 3.
Hossay, Patrick. Unsustainable. London & New York: Zed Books, 2006.
Ibid
H. Steinfeld et al., Livestock's Long Shadow: Environmental Issues and Options, Livestock, Environment and Development. 2006.
U.S. Emissions Inventory 2009: Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2007
http://www.sustainabletable.org/issues/soil/
Ibid
Hossay, Patrick. Unsustainable. London & New York: Zed Books, 2006.
http://www.sustainabletable.org/issues/soil/
Hossay, Patrick. Unsustainable. London & New York: Zed Books, 2006.
Global Environmental Outlook 3: Chapter 2, page 3
The Evolution of Industrial Vegetable Production
P. Warshall. Tilth and Technology: The Industrial Redesign of Our Nation’s Soils
http://www.sustainabletable.org/issues/soil/
Ibid
Hossay, Patrick. Unsustainable. London & New York: Zed Books, 2006.
http://www.sustainabletable.org/issues/waterpollution/
Hossay, Patrick. Unsustainable. London & New York: Zed Books, 2006.
http://www.nytimes.com/2008/01/27/weekinreview/27bittman.html?_r=1
http://www.britannica.com/EBchecked/topic/135192/contour-farming

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