Sunday, June 30, 2013

Global Warming

The earth has a natural system of balancing the absorption and release of heat, that it absorbs from the sunlight, but for the last few years, the balance seems to be under threat. There have been enormous increase in gases like carbon-dioxide, methane, nitrous oxide etc.

          As the temperature rises, there is a rise in sea level, due to melting of glaciers and the ice sheets of Greenland and Antarctica. While sea level is expected to rise almost every year but a considerable variation is seen nowadays. In some regions the rise in sea level, may be almost nil, but other might experience a rise as much as twice the global average. The prediction are that the rise in sea level in some parts of north pacific and to the west of Greenland may be comparatively more and it can spoil the ecological balance of the respective region.

        As per the latest report of UK Met office's Hadley centre for Climate Prediction and Research, global warming over the next century might turn out to be much worse than estimated. If the Green House Gas(GHG) emissions are stabilised, which means immediate cut of 60-70% emission of carbon dioxide globally, even then the rise of atmospheric temperature would be 1 degree C and the rise in sea level would be approximately 1 meter. Based on the finding of Intergovernmental Panel on climate change(IPCC), the center predicted that the warming overland could be a 6 degree C in temperature by 2100, that is 2 degree C higher than the earlier estimates.

        As per the findings of a joint study conducted by an Indian Institute of Technology New Delhi and Hadley Centre, the global warming may also cause a good increase in rainfall over western coastline of India.

Effects of Afforestation:-

It is assumed that planting more trees will solve the problems as the trees absorb more carbon dioxide, but it is wrong presumption.Planting more trees will absorb carbon dioxide from the atmosphere in some parts of the world, but in other parts, global warming may hamper the growth of trees or even may cause their destruction. Therefore afforestation may not be a perfect solution to this problem. One important point to note that forest area is usually darker than the other areas, especially when the surface is snowclad and being darker absorbs more solar radiation than land surface and so the benefits of their carbon intake could be reduced and in some areas be reversed by the darkening effect. Dying forests might result in greater emission of carbon dioxide, thus changing the climate to our peril.

          The Hadley center reported that the average temperature in 1999 was lower than that of the year 1998, but still the year 1999 was the fifth warmest year since global records began in 1860. The centre has further discovered that by 2050, the trees and soils will start falling and perishing which will result in less absorption of carbon dioxide.

           Global warming due to sunlight is likely to be set off or reduced to some extent by volcanic aerosols. During the 21st century, large scale reduction in the amount of rainfall is being expected in some areas such as southern Africa, Australia, Central America and the northern region of South America. The highest increase in precipitation over land may occur in East Asia, Central Africa, Eastern South America and at high latitudes.

           The Hadley centre has also predicted that Antarctica ice may may have all melted away by 2100, if urgent precautionary measures are not taken to cut down emission of green house gases. The melting of ice is due to warming of water of the North Atlantic as well as due to rising air temperature in the region. Melting ice from the frozen continents shall increase the level of sea. Melting of sea ice can further accelerate global warming as the ocean surface would not now reflect as much sunlight as ice sheets.

Adverse effects of Global Warming

1) Antarctica home of penguin is getting hotter slowly and gradually. The annual melt season has increased upto three weeks in the last twenty years.
2) Mount kili Manjaro has lost 75% of its ice cap since 1912.The ice on this Africa's highest peak could vanis within next 15 years if no remedial measures are taken.
3) Venezuelan mountain peaks had only two glaciers today out of six.
4) India's worst heat stroke killed more than 2500 people in May 1998.
5) Polar Bears in Hudson Bay are having fewer cubs, possibly as a result of earlier spring ice breaks up.
6) Coral reefs suffer from the loss of algae that colour and nourish them. The process is called bleaching is caused by warmer ocean.
7) Florida farmland upto 300 meters inland from Bisayne Bay is being infiltrated by salt water rendering the land too toxic for crops. Salt water is also nibbling at the edge of farms on Maryland's eastern shore.

             According to World Meteorological Organisation, deaths from heat waves in big cities are expected to double world wide over the next two decades, if no measures are taken to check the global warming. In the largest cities of USA, an average of 1500 deaths take place every year. It is expected to increase by 3000-4000 till 2020.

             A study conducted by Indian Ocean Experiment(INDOX) reveals that the effect of aerosols in the atmosphere will magnify the warming over several developing countries. The study indicats that precipitation might change over tropical regions due to aerosols. Aerosols have both a warming and cooling effect in the climate. On average estimation, aerosols are expected to have cooling effect as they indirectly help in the formation of cloud droplets, making clouds more bright and more reflective.

            In 1992, the United Nations Framework Convention on Climate Change(UNFCCC) was adopted. It recognised that the industrialized countries mere mostly responsible for increased Green House Gases, concentration in the Earth's atmosphere and should be the first to act against climate change.

            In 1997, United Nation's conference on global warming was held in the ancient Japanese Capital of Kyoto for ten days, the climate change meet lay deadlocked as none was ready to take initiative to check the further damage to planet Earth. USA and 37 other industrial nations agreed to binding reduction in their Green House Gas emission by 2012, setting out a target of five percent below 1990 levels. The next meeting held at Buenous Aires, where it was agreed on Nov 14 1998 to set a time table for discussing by 2000 the many issues that still needs to be settled.

           Actually USA and Europe want that other developing countries like India, China should act as per the accord signed at Kyoto, but India, China have their own reasons as these countries, industrialization has just began, while developed countries who are actually responsible for the global warming must act fact to have some remedial measures.

          In a nutshell the global warming has become a grave threat to the ecological balance of the earth. The civilization is moving slowly towards a doomsday. All the nations particularly the most developed countries have to be active to take immediate actions on the matter, otherwise the human race shall have to face an unimaginable peril and the day is not too far.

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