Global Warming Controversity - Referat
Diverging Views about the Origin of Global Warming
During the next decades the earth´s climate will change dramatically. This fact is undisputable among scientists. One important sign provides the rising temperature which has risen for 0,6 degree during the 20th century. Scientists draw a scenario of a climate catastrophe: due to melting continental ice the ocean circulation gets out of balance. Refering to recent studies by Professor Harry Bryden the Gulf Stream is reduced for 30% between 1992 and 2004. As a consequence of this the temperatures in northern Europe could drop. The worst scenario includes resisting snow in the summer so that the continental ice field will grow and cover large areas thus an escape of humans and animals will be necessary. In order to completely understand the reasons for a possible climate change resulting from global warming, both anthropogenic and natural reasons should be examined in detail.
Both advocates and opponents of the human-induced global warming theory call increasing natural disasters a sign for a climate change. The number of storms over the Atlantic Ocean has risen significantly, from which some caused tremendous damages in middle Europe. Furthermore, one have to allude the direful flood waters of diverse rivers in Germany in 2002 which appear today every second year instead of every 50 years like in former times. Not to mention the horrible draughts in the USA which led to 40% crop loss in 2003. Among scientists it is beyond all question that accumulating extreme weather events represent a first hint for the expected climate change.
The warming of the last 20 years is caused by human activity. First of all, coal-burning power plants, automobile exhausts and factory exhaust fumes contribute billion tons of carbon dioxide and other greenhouse gases into the earth's atmosphere each year. Additionally, animal agriculture, manure, natural gas and rice cultivation contribute about 250 million tons of methane each year. About half of human emissions have remained in the atmosphere. In view of this fact, the atmospheric concentrations of CO2 and CH4 have increased seriously above pre-industrial levels since 1750. About three-quarters of the anthropogenic emissions of CO2 to the atmosphere during the past 20 years is due to fossil fuel exhaustion. The rest is predominantly on account of land-use change, especially deforestation. Ultimately, there are various human origins which come into question concerning the greenhouse effect.
Opponents argue the climate is changing beyond natural variations. Their first argument represents the incessantly changing sun activity on account of the earth´s course round the sun. This theory enables the scientists to justify warmer and colder periods. For example, in tertiary the global temperature was 20 degree higher than today thus a palm-vegetation dominated in Germany. Secondly, they claim CO2 in the atmosphere is mainly volcanic in origin which is responsible for 97% of the CO2 found in the atmossphere. In brief, earth's climate has been both colder and warmer than today and mechanisms that do not involve human greenhouse gas emissions adequately explain these changes.
All in all it is to assert that the climate change is natural but the human greenhouse gas emissions accelerate it. One has to affirm that the natural global warming theory cannot absolutely be supportable. Studies about anthropogenic CO2 emissions disprove the equivocal and inconceivable thesis that 97% of the CO2 is of volcanic origin. Apart from this, the general idea that the fluctuations of the solar activity are responsible for different climate periods is in principle comprehensible. Finally one can sum up that the climate is changing beyond natural variations which are influenced by humans.
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