Реферат: Global Warming Essay Research Paper Introduction to
Global Warming Essay, Research Paper
Introduction to Global Warming
Climate change is neither new nor unusual. Throughout the history of the earth, the average surface temperature, climate and greenhouse gas concentrations have changed, sometimes gradually other times quite sharply. During the past 10,000 years the earth has been in an interglacial period with a fairly stable climate, surface temperature, and greenhouse gas concentration1. The problem that has arisen in recent times is when scientists analyze the past 150 years, especially the last 50. Scientists have found an increased greenhouse gas concentration, making the 20th century the hottest in the last 10,000 years.
Although the earth has undergone periodic changes known as global cooling and global warming, today’s global warming is unique, due to human influences. The greenhouse effect is essentially gasses in the atmosphere trapping heat, rather like a car window does in the summer. The major heat trapping gasses found in the atmosphere are; CO2 and water vapor- which are found in large quantity, 03(ozone), ch4(methane), and N2O(nitrous oxide)-which are better heat trappers but found in smaller quantity, CFC’s and PFC’s- which are very potent and destroy ozone. The rapid elevation of these gasses in the past fifty years have been the cause for concern of scientists calling it a global warming problem.
Global warming is a natural process as well as a human assisted process. Solar flares and sunspots along with natural elevation of greenhouse gasses due to volcanic activety are the natural causes for global warming. Dr. Judy Lean, a leading astrophysicist, looked at global warming trends from 1860 to the present day. Her research has found from 1860 to 1970, global warming was largely due to natural sources. But from 1970 to the present natural sources accounted for only one-third the increase while human influence accounted for the remaining two-thirds of the increased greenhouse effect.
The increase in greenhouse gasses from human sources comes from a variety of things. Elevated Co2 levels, which have been increasing at a rate of 0.5% per year, largely come from the burning of fossil fuels(70-75%), especially coal. Deforestation and plant burning account for the remainder. Increased Methane and Nitrous oxide in the atmosphere are mostly due to agriculture; rice patties, cattle, termites and decomposition of dead tissue. The improper burning of natural gas, natural gas leeks from oil and gas production and pipelines also contribute to these elevated levels. CFC’s and PFC’s are a purely human addition to the atmosphere. Air conditioners, refrigeration, and plastic foam production account for these elevations.
A small change in climate can cause a great deal of change. Many biomes would seriously be affected. A 10C change in climate would cause a 100 mile shift in biomes from the equator. This shift would cause serious economic and humanitarian problems in the United States. Scientists predict by 2100 a climate change of between 10c,at best and a 3.50c, at worst, could happen. Lets assume say a 20c climate change were to occur. A 200 mile shift in the crop band would occur, putting the nations breadbasket largely in Canada, devastating the U.S. economy. The tundra soil of Canada not being as good for agriculture as the plains and rolling hill of the middle eastern United States and the lack of established agribusiness could account for a 10 to 50 decrease in food production. Rain and weather patterns would shift, causing many cities to be relocated. Hurricanes, droughts, flooding and other severe weather would be more prevalent due to increased water vapor in the atmosphere. A severe impact on forestation and biodiversity would occur. Evolutionary adaptation to the new climate takes time and the? mile per year movement of forests would not be able to out run it. Aquatic systems would be greatly effected. Coral reefs which are very temperature sensitive would be devastated. Approximately a two foot increase in sea level which is not due to polar ice cap melting but rather because water expands when heated. One-third the worlds population lives in coastal areas, causing the flooding of many coastal cites. Flooding would cause the disruption of rice production and salt water contamination of aquifers adding to the agricultural problem. Also an influx of tropical disease such as fungal infections and insect carried disease normally found in rainforests would make its way into the United States.
The atmosphere and climate system is very complex. It is very hard to know the threshold level of positive feedback systems, which are stimulated due to changing atmospheric conditions. Some scientists argue climate change is a naturally occurring process because records indicate it has happened many times before. Co2 production can not be stopped. The world would have to cut 70% of its emissions in order to stop the increase. In order to slow the increase, the efficient use of fossil fuels must be adapted. Natural gas gives off very little co2 and methane if burned properly. Deforestation must also be stopped in order to give natural co2 scrubbers, plants, a chance to aid in the process. Governmental programs have also been implemented. A carbon tax has been considered along with the passing of the 1990 Clean Air Act, aimed at lowering emissions and cleaning air pollution. On a world wide scale, the Kyoto Accord in 1997, in which 159 nations agreed to work together to decrease Co2 emissions by 5.5% by 2012. The United States agreed, since it accounts for 25% of the worlds total emissions by 1990 figures, to cut its emissions by 7%.
Global warming is still a major issue in world and U.S. politics. Conservatives argue for more market-orientated solutions, resulting in the imposition of taxes, resulting in higher prices for environment polluting goods. Liberals on the other hand advocate stiffer industry regulation and more direct controls. Any action taken, whatever the ideology, can only help to solve an increasing problem but at what cost to the consumer?