Wednesday, July 31, 2019

Human Effect on Climate Change Essay

Very few people doubt that it is normal for there to be climate change. The rotation of the earth on a tilted axis leads to this, as well many natural events, like volcanic eruptions, earthquakes and hurricanes. However, human activities are having a much greater impact on climate change. For example, the jump in earths’ population from 1950 through 1985 more than doubled from 2. 5 billion to over 5 billion. (Meyer, 1996: 24) The importance of this growth is a drain on the Earths’ resources causing even more altering. It is not as much the altering of these resources that are causing climate change but the type of human activities which are taking place, and the way in which they are impacting the climate. One major influence is increased waste and pollution as a result of burning more fossil fuels. The introduction of chlorofluorocarbons in the mid-20th century, which were used for refrigerants, solvents, and propellants, cause a reaction in the atmosphere that break down the ozone layer. (Meyer, 176) CFL’s and burning of fossil fuel create an added layer of insulation around the earth. Since the earth is naturally surrounded by gases the added human processes cause a phenomenon called the greenhouse effect. This is when these gases change and more heat from the sun is retained than before resulting in planetary temperature rise. Changing of seasons and somewhat consistent weather patterns are a normal occurrence on our planet. However, in the past 30 years there have been many natural disasters that can be attributed to climate change and global warming. Massive earthquakes which subsequently cause tsunamis, hurricanes wreaking havoc in areas they never before touched, volcanoes erupting years before the experts predictions and the melting of ice caps causing sea level rise. It is obvious that our normal weather patterns and temperatures have been and are changing. It wasn’t until 1938 when a Mechanical Engineer named Guy Stewart Callendar challenged the Experts. (Weart, 2) Callendar had confirmed more completely than anyone else that his data proved global warming was occurring. Global warming is not climate change but it is a symptom of climate change. Although, Callendar was not a meteorologist, studying weather patterns was his passion and with every spare minute he analysed all the data he could acquire. He showed through his research that as the industrial era was booming it was doing so while burning fossil fuels. These fuels were emitting millions of tons of carbon dioxide into the atmosphere and subsequently adding to the greenhouse effect and climate change. (Weart, 2) This was the first time in recorded history mankind was able to prove humans were damaging the Earths biosphere. Before the great baby boom of the mid-20th century and prior to the industrial revolution in the eighteenth century carbon dioxide levels were at about 265 ppm and today because of human processes it is about 392 ppm. (Pittock,7) Currently carbon dioxide in the atmosphere is increasing about 2 ppm per year and average world temperature is climbing in step with it. Many experts agree that 400 ppm of carbon dioxide will probably cause a temperature rise of about two to four degrees Fahrenheit. (Gossling and Upham, 3-4) If this occurs so many tipping points will have been crossed, or soon will be crossed, that climate change and global warming will become unstoppable, and the point of no return will have been passed. There are a number of potential sources of human activity that impact climate change. A major consideration is that of cause-and-effect, looking at the type of human activities which take place, and then examining the way in which they may be impacting on the climate in order to create change. Some examples are farming with the fabrication and use of fertilizers and pesticides, manufacturing with burning fossil fuels, deforestation, power stations, cars and other vehicles as well as aircraft. The impact from all of them is similar, with the proof being two points. First a hole in the ozone layer over Antarctica, which was discovered in the 1970’s. Second an increase in earths’ temperature of approximately two degree Fahrenheit. (Pittock, 78) There is also a potential for additional erosion of the ozone as a result of the continued use of hydro-fluorocarbons. Therefore, it is the output of this consumption process that is having an impact. The emissions made are also those that are seen to cause longer term damage to the ozone layer. The emissions also have an impact on the climate of the earth either directly or indirectly. Directly this includes the emission of carbon dioxide and indirectly the impact of jet aircraft in the way they emit water vapour in their contrails. (Gossling and Upham,42-43) In the late 1950s Walter Orr Roberts a leading astrophysicist noticed that cirrus clouds were forming daily over Boulder, Co. (Weart, 66) Orr observed that Jet contrails were mixing with the existing cirrus cloud formations to the point of not being able to distinguish between either. This phenomenon was occurring daily my mid-afternoon from the heavy airline traffic. (Weart, 66) The fuels used by aircraft are the main problems. Aviation fuel is made up mostly of kerosene, which originates from fossil fuels. (Gossling and Upham, 311) There are two main problems with the combustion of kerosene by the aircraft; the waste products they produce are major pollutants as well as the carbon dioxide and water vapour. Both of these have a negative impact on the atmosphere. (Weart, 132-133) If we consider the problem of carbon dioxide, it needs to be remembered that aviation fuel is only one source of this pollution, and as such, it is adding to the overall totals that are creating climate change and global warming. The creation of added clouds by water from jet exhaust adds to the global warming effect and climate change by trapping more heat in earths’ atmosphere. The increased amount of particles in the air that help trap the heat from escaping from the earth’s atmosphere are one of the culprits of the greenhouse effect. This has been achieved by pollution put into the atmosphere over the last century, most notably since the industrial revolution (Meyer, 37). Since then there has been a greater and greater amount of waste containing carbon, as well as other gases and chemicals, burned and released into the atmosphere. Also, during this time there has been large scale deforestation and the carbon that was contained in these large areas, locked away in the wood was then released directly into the atmosphere (Meyer, 60). The increase in carbon from the release due to deforestation alone is projected at accounting for 15% of the greenhouse effect between 1990 and 2025 (Meyer, 61). When we then consider the relatively high amounts of carbon in other deposits such as coal that is burned for power we can start to appreciate why the levels of carbon dioxide in the atmosphere are increasing. The earth’s atmosphere has always contained several types of gases. It also has a certain percentage of carbon dioxide and other greenhouse gases. (Meyer, 1996: 150) Carbon dioxide lets the short wave length radiation from the sun through and then the rays hit the earth and warm it. The earth re-radiates longer wave length heat radiation but the carbon dioxide won’t let most of this long wave radiation out again. (Pittock, 7) As carbon dioxide levels increase in the atmosphere, the more trapped heat and the hotter the earth gets. However, we need some carbon dioxide in the atmosphere otherwise all the sun’s heat would be lost and temperatures would drop by ninety one degrees Fahrenheit and we would quickly freeze to death. Therefore, the climate is being changed as a result of increasing levels of carbon dioxide and chlorofluorocarbons being placed into the atmosphere, which is helping to retain heat and as a result is having an impact on climate, increasing the temperature of the planet and impacting on natural processes. Under current conditions it is estimated that by the end of the 21st century global sea level temperatures could rise as much as thirty nine degrees Fahrenheit. (Gossling and Upham, 3-4) Obviously, if this happens life will once again recycle on planet earth.

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