Is Mass Extinction Our Future - Essay Example

Ching Wong Greathouse Biological Anthropology 20 April 2007 Is Mass Extinction Our Future A few hundred millions years ago, there was a group of huge animals living on this planet. They are known as the dinosaurs. However, they were wiped out with many other species from earth about 65 million years ago (Ananthaswamy, 2004). Their depletion was recognized as one of the mass extinctions. There were six mass extinctions identified in the last four billion years, and many scientists are expecting the seventh to happen. They called it the Holocene extinction event (Wikipedia, 2007). It is believed that about one half of the species will be depleted during this era. People believe that this will happen again, but the element of the forthcoming mass extinction might be the same, but enhanced by human factors. Agreeing with Douglas Erwin, finding the real answer to the mass extinctions is not an easy task. There were six prime suspects to the previous mass extinction: asteroid, volcanism, super continent, glaciation, bacteria and methane gas. Each of these contributed quite a lot of change to the planet's environment at that time causing competition for resources like food and water among species. Those that did not survive faced extinction. In today's world, the human population is increasing everyday; it is about 6.5 billion in total now. However, the other resources like land, water, and oxygen do not increase. Humans are not just competing for these resources within its species but also with others that live on this planet. Consequently, the number of some species is reducing while some others have gone extinct. Some would evolve to adapt to the environment. Possible extinction examples will be the depleting number of Malayan Tigers, Hindu Tigers (The Hindu, 2002), pandas (Fritz, 2003), and butterflies in United Kingdom(LSE, 2006). To talk about the possible reason of mass extinction in this era, it is more identifiable as it is something we sense everyday. Reuters last year announced that the human species is spurring a more severe mass extinction than the dinosaurs. Habitats have changed due to the pollution, expanding cities, deforestation, introduction of alien species and global warming (Doyle, 2006). It can be observed that instead of one main reason, it is made up of a combination. I think that this is the possible reason why Douglas Erwin said it is quite difficult to identify which is the real cause of the mass extinction in the past. There are these many factors that contribute; they are all giving different degrees of impact to the environment, which the scientists need to delve into each to know the actual influencing degree. The world population is growing exponentially but the land is so limited. Humans exploit virgin land, like the jungle and mountains. They cut down the jungle and make the mountains flat to make houses and farmland. The equivalence of the whole ecosystem is disturbed. Firstly the flora and fauna in the wild lost their habitat. They cannot even find food that they used to get. As a result, this leads to wildlife extinction. Loss of soil due to loss of plants also caused the river- and seabeds to become shallow. This is obvious with the increase of sea water level. The situation becomes worse when the pole's glacier starts melting due to greenhouse effect! Eventually, the increasingly warming atmosphere triggered the people's interest to study the global warming phenomena. This is how the greenhouse effect situation was discovered. It is estimated that about 15 to 37 per cent of the species will become extinct from now to 2050 if the climate keep on changing (Kirby, 2004). The causes of global warming were identified: excretion of greenhouse gases like carbon dioxide, water vapor and methane, use of aerosol products and depletion of jungle land and ozone layer. Carbon dioxide and methane will trap heat in the atmosphere. They are the by products from the use of fuel energy. Meantime, depletion of jungle land reduces the number of green plants that can convert the carbon dioxide gases back to oxygen. The increase of methane gave similar effect to the environment. As described by the NOVA Science Now website on Mass Extinction, (http://www.pbs.org/wgbh/nova/sciencenow/3318/01.html) methane plays an important role in the previous mass extinction. In addition, the depletion of the ozone layer exposes the surface of the earth to the direct sunlight. The ozone layer acted as a protection layer for earth: it reflects the ultra violet (UV) ray from the sun. Thus, it prevents UV rays from injuring the living. However, the use of halogen compounds (halons and freons) and disposal of it in the atmosphere causes the destruction of the ozone layer (Wikipedia,2007). Without it, earth is heated. In this case, if the atmospheric temperature keeps increasing, the glaciers in Antarctica will keep on melting. In the end, there might be a lot of low land area that will be flooded. The ironic part of the whole thing is, even with the earth flooded. Humans will not get enough water, as it will be polluted. This is the price for the development of the human civilization. Industrial advancement created lots of waste, either toxic or non-toxic; long before we know it they are in the river. Humans always think that rivers and the sea is the best place to dump their waste. The use of pesticides and insecticides make the situation worse. These chemical compounds pollute the underground water and river. Farmers used to use them in overly large doses to ensure the quality of their products. The time when they realized that this idea was wrong, it was too late. A lot of our water sources are polluted. This is especially serious in those under-developed countries in Asia and Africa. The resultant effect is the lost of marine lives like coral and reefs. This indirectly affects the availability of other marine creatures such as fish and prawns as their living depends on the coral and reefs. Again, this is the beginning of extinction for certain marine lives, and the human is the one that started it. In conclusion to this, the mass extinction in the future has begun taking its place. Instead of the natural factors as in the past, this mass extinction event that is going to take place in the near future would be a result of human activities on the earth. Nature has given enough signals so that humans would react to slow down the destruction. It is thus still depending on humans whether to let this great event take place sooner or later. References: Ananthaswamy, A. (2004). Earth faces sixth mass extinction. New Scientist.com news service 18 March, 2004. Doyle, A. (2006) Humans Spur Worst Extinctions Since Dinosaurs. Reuters. http://www.enn.com/today.htmlid=10107 obtained on 16th April, 2007. Fritz, A. (2003) The Giant Panda Paradigm. http://serendip.brynmawr.edu/biology/b103/f03/web1/afritz.html obtained on 16th April, 2007. Kirby, A. (2004) Climate risk 'to million species'. BBC News Online environment correspondent on 7th January, 2004. LSE (2006) Butterfly species facing extinction. http://www.lse.co.uk/ShowStory.aspstory=AX1623517S obtained on 16th April, 2007. The Hindu (2002) The Tiger Trail. http://www.hinduonnet.com/thehindu/mag/2002/10/06/stories/2002100600570800.htm obtained on 17th April, 2007. Wikipedia. (2007) Extinction event. http://en.wikipedia.org/wiki/Mass_extinction obtained on 17th April, 2007. Wikipedia (2007) Haloalkene. http://en.wikipedia.org/wiki/Haloalkane obtained on 17th April, 2007. Read More