Thursday, April 22, 2010
Humans may be a decisive factor in future climate change. The actions we make towards the temperature of the earth and the depletion of the ozone layer are irreversible. A warmer future could result from present-day human activities releasing large amounts of heat-trapping gases into the air. These greenhouse gases are part of the reason for the 1°F (.5°C rise in global average temperature documented over the past 100 years. If the Earth's temperature continues to rise as predicted, future global warming could happen faster than any climate change of the last 10,000 years. If so, future variations in local climate could be even more disruptive than those of the past. Fossil fuels, which release carbon dioxide when burned, are used to generate electricity; heat and light homes and workplaces; power factories and run cars. Unless we reduce population growth and use of fossil fuels, the level of carbon dioxide in the atmosphere will double by sometime in the middle of the next century. The future of Earth's climate may depend partly on the buildup of heat-trapping gases, primarily carbon dioxide, methane, and nitrous oxide, in the atmosphere. Industrialized nations now release the most carbon dioxide. But how can this world wide disaster be stopped? To fully understand the magnitude of this problem, we must look at the causes McDonald 2 of global warming, what is being done to stop the problem, consequences of this issue, and how we can prevent it. What is Global Warming? The depletion of the ozone layer and global warming are a result of the heat trapping abilities of “greenhouse gases”. The glass panels of a greenhouse and the Earth’s atmosphere are both transparent to sunlight, and both trap heat. Energy from the sun drives the earth’s weather and climate, and heats the earth’s surface; in turn, the earth radiates energy back into space. Atmospheric greenhouse gases trap some of the outgoing energy, retaining heat somewhat like the glass panels of a greenhouse. Thus creating the greenhouse effect. At present, the Earth appears to be facing a rapid warming, which most scientists believe results, at least in part, from human activities. The chief cause of this warming is thought to be the burning of fossil fuels, such as coal, oil, and natural gas, which releases into the atmosphere carbon dioxide and other substances known as greenhouse gases. As the atmosphere becomes richer in these gases, it becomes a better insulator, retaining more of the heat provided to the planet by the Sun. Through years of abuse and neglect, the situation continues to worsen. Some may feel that Global warming is inevitable, and that the climate will change no matter what. This is partly true. Climate does change all the time, but it changes slowly. We are doing it at enormous speeds, 60 times faster than normal. McDonald 3 Greenhouse Gases All life on Earth relies on the greenhouse effect, without it, the planet would be colder by about 33-Celsius degrees, and ice would cover Earth from pole to pole. However, a growing excess of greenhouse gases in Earth's atmosphere threatens to head in the other direction, toward continual warming. Carbon dioxide is the most abundant greenhouse gas followed by methane and nitrous oxide. Carbon dioxide flows into the atmosphere from many natural processes, such as volcanic eruptions; the respiration of animals, which breathe in oxygen and exhale carbon dioxide; and the burning or decay of organic matter, such as plants. Humans escalate the amount of carbon dioxide released to the atmosphere when they burn fossil fuels, solid wastes, and wood products to heat buildings, drive vehicles, and generate electricity. At the same time, the number of trees available to absorb carbon dioxide through photosynthesis has been greatly reduced by deforestation, the long-term destruction of forests by indiscriminate cutting of trees for lumber or to clear land for agricultural activities. Methane is an even more effective insulator, trapping over 21 times more heat than does the same amount of carbon dioxide. Methane is emitted during the production and transport of coal, natural gas, and oil. Methane also comes from rotting organic waste in landfills, and it is released from certain animals, especially cows, as a byproduct of digestion. Nitrous oxide is a powerful insulating gas released primarily by burning fossil fuels and by plowing farm soils. Nitrous oxide traps over 270 times more heat than does the same amount of carbon dioxide. Since the beginning of the industrial revolution, atmospheric concentrations of carbon dioxide have increased nearly 30%, methane concentrations have more than McDonald 4 doubled, and nitrous oxide concentrations have risen by about 15%. These increases have enhanced the heat-trapping capability of the earth’s atmosphere This chart shows how much warming could be caused by each of the gases that human activities release. Carbon dioxide accounts for three fourths of the predicted increase in the greenhouse effect. History of Global Warming This graph shows changes in global temperature since 1880, when reliable temperature records became available worldwide. Each vertical bar represents the global average temperature for that year. The curved line shows the overall trend. The global average temperature has risen nearly 1°F since 1880. McDonald 5 During the industrial revolution we began to slowly alter our climate and environment by changing agricultural practices and industrial practices. These new practices have causes a change in the chemical composition of the atmosphere through the build-up of “greenhouse gases”. Due to the exponential growth of the world's population and the fact that nation economies and the use of technology are also growing, the global temperature is expected to continue to increase by an additional 1.0 to 3.5 degrees Celsius by the year 2100. This seemingly subtle change in the global temperature could prove to have catastrophic results. We're altering the environment far faster than we can possibly predict the consequences. This is bound to lead to some surprises.Dr. Stephen Schneider, National Center for Atmospheric Research. The earth’s temperature would rise on it’s own, but that takes thousands of years, were doing it in a century. Nobody can really predict what may happen. What is Being Done? The developed countries are all working to reduce greenhouse emissions. Several European countries impose heavy taxes on energy usage, designed partly to curb such emissions. Norway taxes industries according to the amount of carbon dioxide they emit. In The Netherlands, government and industry have negotiated agreements aimed at increasing energy efficiency, promoting alternative energy sources, and cutting down greenhouse gas output. In the United States, the Department of Energy, the Environmental Protection Agency, product manufacturers, local utilities, and retailers have collaborated to implement the Energy Star program. This voluntary program rates appliances for energy use and gives some money back to consumers who buy efficient McDonald 6 machines. The Canadian government has established the Fleet-Wise program to cut carbon dioxide emissions from federal vehicles by reducing the number of vehicles it owns and by training drivers to use them more efficiently. By 2004, 75 percent of Canadian federal vehicles are to run on alternative fuels, such as methanol and ethanol. Many local governments are also working against greenhouse emissions by conserving energy in buildings, modernizing their vehicles, and advising the public. Individuals, too, can take steps. The same choices that reduce other kinds of pollution work against global warming. Every time a consumer buys an energy-efficient appliance; adds insulation to a house; recycles paper, metal, and glass; chooses to live near work; or commutes by public transportation, he or she is fighting global warming. Kyoto Protocol As this issue becomes more prevalent, pressure has been put on international leaders to face this problem and come up with a valid solution. International cooperation is required for the successful reduction of greenhouse gases. In 1992 at the Earth Summit in Rio de Janeiro, Brazil, 150 countries pledged to confront the problem of greenhouse gases and agreed to meet again to translate these good intentions into a binding treaty. In 1997 in Japan, 160 nations drafted a much stronger agreement known as the Kyoto Protocol. This treaty, which has not yet been implemented, calls for the 38 industrialized countries that now release the most greenhouse gases to cut their emissions to levels 5 percent below those of 1990. This reduction is to be achieved no later than 2012. The United States voluntarily accepted a more ambitious target, promising to reduce emissions to 7 percent below 1990 levels; the European Union, which had wanted McDonald 7 a much tougher treaty, committed to 8 percent; and Japan, to 6 percent. The remaining 122 nations, mostly developing nations, were not asked to commit to a reduction in gas emissions. Most developing nations fear this will pause their development, The Kyoto Protocol will not be binding until nations accounting for 55 percent of 1990 greenhouse gas emissions have ratified it. To date, only three small island nations: Fiji, Tuvalu, and Trinidad and Tobago, have actually ratified the treaty. Most countries are waiting for ratification by the United States, at present the source of one-fifth of greenhouse gas emissions. The Congress of the United States has so far refused ratification, partly to protest the exemption of developing nations from efforts to reduce emissions. Some critics find the Kyoto Protocol too weak. Even if it were enforced immediately, it would only slightly slow the buildup of greenhouse gases in the atmosphere. Much stronger action would be required later, particularly because the developing nations exempted from the Kyoto rules are expected to produce half the world's greenhouse gases by 2035. The most influential opponents of the protocol, however, find it too strong. Opposition to the treaty in the United States is spurred by the oil industry, the coal industry, and other enterprises that manufacture or depend on fossil fuels. These opponents claim that the economic costs to carry out the Kyoto Protocol could be as much as $300 billion, due mainly to higher energy prices. Proponents of the Kyoto sanctions believe the costs will prove more modest $88 billion or less much of which will McDonald 8 be recovered as Americans save money after switching to more efficient appliances, vehicles, and industrial processes. We are all generally guilty of contributing to the effects of Global Warming: In the United States, approximately 6.6 tons (almost 15,000 pounds) of green house gases are emitted per person every year. And emissions per person have increased about 3.4% between 1990 and 1997. Most of these emissions, about 82%, are from burning fossil fuels to generate electricity and power our cars. However there are many things you yourself can do to reduce the emissions of fossil fuels, and in turn prevent global warming. For example, things as simple as: car pooling, keeping your vehicle well-maintained, using energy efficient appliances, etc… Also investing in a new hybrid vehicle is without a doubt a smart decision for the environment. The first hybrid available in Canada is the “Honda Insight” This car is powered with a combination of furl and electricity, and will be capable of driving approximately 70 miles on a single gallon of gasoline. We, as an entire race, need to become more aware of the future repercussions of our seemingly harmless daily activities and choices. This will ensure a safe, temperate future for generations to come.