Atmosphere And Weather

A look at Climate Change over the last Million Years



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"A look at Climate Change over the last Million Years"
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It is the year 2012 and many people are discussing the potential doom of the planet earth and the extinction of human race due to an unprecedented catastrophe. Although not as extreme as some of the layman-talk, super powers of the world and almost all environmental organizations have started discussing the issue of climate change as having a significant effect on the global warming and the associated environmental hazards. Many point the finger towards the acts of humans as responsible for the present state of the climate although some disagree. However, by looking at the climate change over the last million years it is possible to shed light to the potential culprits for ‘warming the earth’.

When looking back one to two million years of climate change in the world, scientists have recognized several distinct periods. These are the Bolling-Allerod period, which dates back from 14,500 to 12,900 years, the Younger Dryas period, which dates back to 12,900 to 11,600 years, the Medieval Warm Period between 800 – 900 A.D, the Little Ice Age between 1300 – 1900 A.D and the current warming from the year 1861 to present. Although most of these classifications are based on predictive evidence and fossil studies, it illustrates an important aspect of climate change, which is that it has been in existence from the time the earth was born.

According to scientists, the so-called ‘recent ice age’ seems to be having a cyclical presence over the last 1 million years. The reason for their observation is the changing orbital patters of the earth in relation to the sun, which also follows a similar cyclical pattern. These orbital patters are called the Milankovich cycles and at present scientists believe that the earth is travelling in a more warmish interglacial period, meaning relatively distant to the sun, as the orbital pattern is an elliptical route. At the same time, it is believed that the present warmish conditions have lasted for around 10,000 years. Apart from the eccentricity, which is the orbital pattern, two other variables of the earth, which is the obliquity and the precession, shall also influence the climate changes.

Thus, the scientists expect the earth to undergo ice ages at 100,000 year intervals. However, although the amount of sun light received will drive the changes in the climate, having more sunlight in the northern Atlantic will influence the climate more than having more sunlight in the southern latitudes. According to an article published in the Discovery News, the Arctic will reliably amplify whatever the global climate is doing. Thus, if the world experience 3 degrees colder climate the Arctic will amplify the cold to around 9 to 12 degrees. Similarly, a rise in the temperature will also be amplified.

Therefore, when looking back the cyclical climate changes that have taken place for over millions of years, it seems like there is little that humans can do in order to prevent a potential ice age from occurring. However, scientists agree that, human interference with the environment has worsened the situation to a certain extent and therefore the world has become a rather uncomfortable place to live in. In any event, climate change seems to be an ongoing process that will last until the earth exists although any catastrophic changes at present may cause more damage than has been caused in the past. 

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More about this author: Dr Pandula Siribaddana

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  • InfoBoxCallToAction ActionArrowhttp://gly.fsu.edu/~kish/dynamic/global/LS.htm
  • InfoBoxCallToAction ActionArrowhttp://gly.fsu.edu/~kish/dynamic/global/LS.htm
  • InfoBoxCallToAction ActionArrowhttps://sites.google.com/site/ents288food/abrupt-climate-change/l
  • InfoBoxCallToAction ActionArrowhttp://news.discovery.com/earth/arctic-warming-amplification.html