The world, besides facing human threats also undergoes natural destructive causes such as Global Warming, though the fact is that global warming is also a man made threat to the earth.

Global warming is the most contemporary and extensively discussed factor which could probably bring an end to the living creatures of the World. Global warming is growing as a most threatening challenge to the world in 21st century. The paper argues about causes which occur due to global warming in the past, present and in future. The paper in detail explains the destructive factors which would possibly occur due to global warming.Finally, the paper concludes with few recommendations to overcome global warming. Past and Present impact of Global Warming During the last three centuries, atmospheric levels have increased by about 30%.

The increase in greenhouse [CO. sub. 2] largely comes from burning of fossil fuels [like coal, natural gas and oil] in automobiles and power plants. If global warming trend continues, melting polar ice along with the thermal expansion of the oceans could raise the sea level, flooding coastal cities and many agricultural landscapes could dry out, becoming deserts.Some scientist speculated that global warming may perturb ocean circulation patterns to result in another ice age . As the result, industries and governments were being now urged to reduce man-made greenhouse gasses.

One of the study carried by Chris D Jones, Met office’s Hadley Centre for climate prediction and Research in Bracknell, UK appeared in Journal ‘Geographical Research Letters , Published by the American Geophysical union revealed that by the end of the 21st century , the increase in carbon dioxide and decrease in sulphates in the environment will cause a substantially higher global warming of 5. degrees Celsius (9. 9 degrees Fahrenheit ) compared with 4 degree Celsius ( 7 degrees Fahrenheit).Global warming may melt the glaciers that are floating in the Artic and Greenland which in turn may result in the sea levels to soar.

The glaziers at Himalayas are melting at phenomenal rate and this can cause unprecedented and havoc flooding in the great plain areas of India. It has compelled more than 80% of birds, amphibians, plants and other organisms to change their timing of reproduction or migration, length of growing season, population size, or population distribution.Global warming also compelling the birds to advance or delay their hatching and due to this, the availability of food for their chicks become scarce as by that time the caterpillar season is on the wane. Moth relies on oak leaves as their food and moth’s caterpillar hatching is always happenings when the oaks’ leaves open.

If Moth hatches five days earlier or two weeks later, caterpillar has to starve because of non availability of edible oak leaves. One of the research proves that oak burst occur about 10 days earlier than it did 20 years ago.As per Christian Both of the University of Groningen in the Netherlands, the pied flycatcher which migrates 5000 kilometers from tropical West Africa to TP De Hoge Veluwe, in Norway seems to be affected from mismatch between nesting and wintering –site conditions due to global warming . Montana State University ecologist William Fraser finds that global warming is causing the extinction of Adelie penguins living on the western coast of the Antarctica Peninsula and over the past 30 years, there is a startling 70% decline in the number of Adelie penguins nesting on a number of islands in the vicinity of U. S research bases in Antarctica.

In the last 50 years, winter temperature in Antarctica peninsula has increased by six degrees Celsius and it has resulted in an increased snowfall which obstructs penguin to hatch and breed their chicks. It is to be noted that all the carbon dioxide (CO2) we exhales arrives from the breakdown of molecules such as carbohydrates and fats in the effort to produce energy. These emitted CO2 by humans have to be absorbed by plants and animals in turn eat these plants as their food. If there is indigestion by animals or decrease in size of plants or decline of animals globally, may result in higher CO 2 in atmosphere resulting in global warming.Due to global warming, hurricanes like Katrina not only become very strong and severe but also more frequent and devastating. There was unusual weather extremes in Europe with deadly heat weaves in which over 30000 people died in 2003, tumultuous rainstorms in southeastern Europe, forest fires in Portugal, drought throughout Iberia , earth quakes in Asia , Tsunami in Asia , large volcanic out gassings of carbon dioxide , ash and sulphur etc.

Future impact The Intergovernmental Panel on Climate Change [IPCC] predicted that the average global temperature will likely to increase by 1. [degrees] to 5. 8 [degrees] C by the end of the 21st century and may result in retreat of glaciers and ice caps. Scientist forecast that the global warming will rise between five and nine degrees by middle of the 21st century followed by a sea –level rise of one to four feet. If polar ice caps melt due to this, coastal cities like San Francisco, New York and New Orleans may be immersed by the surging water.

If global warming continues increased temperature will destroy the agricultural land in the northern hemisphere of the world especially in countries like U. S. ew reports foretells that the level of Great Lakes will drop between two to eight feet in near future. Scientist anticipates that the earth may experience the greatest warming effect in next 50 years which would result in complete melting of sea ice on the poles.

Present situation in the earth serves as good substantial reason to put forward that more powerful hurricanes may occur due to global warming. The reason behind is warmer ocean generates more forceful storms. Connoisseurs consider that, global warming might augment the concentration of hurricanes by over fifty to sixty percent.They also consider that, in near future hurricanes to the populated areas would be even more severe as greater sea levels are forecasted for the coming century.

In addition, increased sea level could result in beach erosion and steep banks along the coastal areas and even further there are more possibilities for salt water mixing with the fresh ground water in coastal areas. In 1992 there was a threatening report published by United Nations which stated that if green houses gas discharge prolongs in the same phase, then, the coastal plains of Netherlands and Bangladesh would possibly be destroyed due to flood by the year 2100.Additionally, Maldives islands would completely disappear with only tow feet increase in the sea level. Scientist have predicted that if global warming is unchecked, an increase of 6 meters in sea level is forecasted from that of present level in two or three decades and if that happens, South Florida and New Orleans will be flooded again.

Not only New Orleans will be flooded but there will be extinction of rare species like sea turtles and precious coral reefs. Unusual rise in temperature and deterioration of air quality may result in human health problems like heat stroke, head exhaustion, asthma and other respiratory diseases.New Orleans being a busiest cargo port in U. S. A, the flooding may collapse the port infrastructure facility.

New Orleans may face more Katrina’s in another ten to fifteen years if the GHG is being left unchecked. Rebutting Factors Few scientists argue that global warming is not a peril and the globe is fundamentally cooling off. These scientist squabbles that the grounds for the causes are not clearly understood and hence it is impracticable to conclude that global warming is entirely a natural happening.In addition, these people disagree that the global warming is a misleading factor and it is not an indication of global disaster. Furthermore, commercialist and industrialist argue that human beings are highly adaptable to changes which could result from global warming. However, they refuse to argue about the environmental influence on climatic changes.

In addition to the above some contenders believes that most changes in the earth are caused due the energy fluctuation in the sun. However, huge sunspot actions are partially accountable for the “Ice Age” from 1450 to 1850.During this period the temperature fluctuation was only 2 to 3 degree Fahrenheit. Further, few researchers deems that smoke from the fire of tropical forest could result in cooling of the climate. But the fact is the fire generally builds a warming effect of the green house gas. Moreover, when considering the rising of sea level, it is clear from the occurring events such as Tsunami in 2003 in Asia has led to depletion of several coastal areas due to geological factors.

As a consequence the ocean level would not increase but the coastal areas continue to exhaust.Conclusion Thus, global warming will be having drastic effect on developing countries than wealthier countries. Developed countries should be urged to reduce personal energy consumption, paying a “Carbon tax” for the environmental costs of global warming, subsidizing energy -efficient technologies Preventive measures like carpooling, planting more trees has to be undertaken at the earliest. Damage caused by emissions in the future is directly associated to various factors like economics, demographics, institutional developments and technology policies.The government, business, individuals can help to reduce the green house gas emissions by adopting the measures like increasing of Energy efficiency standards, usage of renewable energy sources like wind, solar shall have to be encouraged and Development, restoring and protection of forests which act as significant storehouses of carbon. If no imminent action is taken immediately, the globe may be engulfed by surging ocean waters in the near future.