Global warming is the ‘talk of the town’ in this century, with its detrimental effects already being brought to limelight by the recurring events of massive floods, annihilating droughts and ravaging cyclones throughout the globe. The average global temperatures are higher than they have ever been during the past millennium, and the levels of CO2 in the atmosphere have crossed all previous records. A scrutiny of the past records of 100 years indicates that India figures in the first 10 in the world in terms of fatalities and economic losses in a variety of climatic disasters. Before embarking on a detailed analysis of Global warming and its impacts on Indian climate, we should first know what climate, green house effect and global warming actually mean. CLIMATE:
The climate is defined as’ the general or average weather conditions of a certain region, including temperature, rainfall, and wind’. The earth’s climate is most affected by latitude, the tilt of the Earth's axis, the movements of the Earth's wind belts, and the difference in temperatures of land and sea, and topography. Human activity, especially relating to actions relating to the depletion of the ozone layer, is also an important factor. The climate system is a complex, interactive system consisting of the atmosphere, land surface, snow and ice, oceans and other bodies of water, and living things. GREEN HOUSE EFFECT:
Green House effect is the phenomenon whereby the earth's atmosphere traps solar radiation, and is mediated by the presence in the atmosphere of gases such as carbon dioxide, water vapor, and methane that allow incoming sunlight to pass through, but absorb the heat radiated back from the earth's surface. Thus the Green house gases (GHGs) provide a blanketing effect in the lower strata of the earth’s atmosphere, and this blanketing effect is being enhanced because of the human activities like burning of fossil fuels etc. GLOBAL WARMING:
‘Global warming is defined as an increase in the average temperature of the Earth's atmosphere, especially a sustained increase great enough to cause changes in the global climate’. The term global warming is synonymous with Enhanced green house effect, implying an increase in the amount of green house gases in the earth’s atmosphere, leading to entrapment of more and more solar radiations, and thus increasing the overall temperature of the earth. EFFECT OF GLOBAL WARMING ON THE EARTH’S CLIMATE:
Detailed researches of climatic events of the past 150 years have revealed that the temperatures have risen all over the globe, with the warming occurring in two phases. The first phase was from 1919 to 1940, with an average temperature gain of 0.35°C, and the second phase was from 1970 to the present, exhibiting temperature gains of 0.55°C. Records show that the past 25 years have been the warmest time of the past 5 centuries. The global warming has resulted in the warming of the oceans, rising of the sea levels, melting of glaciers, and diminished snow cover in the Northern Hemisphere. The above map illustrates an analysis conducted by the Goddard Institute for Space Studies (GISS) in New York City, based on temperatures recorded at meteorological stations around the world and satellite data over the oceans. The map illustrates how much warmer temperatures were in the decade (2000-2009) compared to average temperatures recorded between 1951 and 1980. The Arctic regions exhibited the most severe warming as depicted in red color. The blue colored areas show the lower than normal temperatures, and thus are very few. The recent catastrophic climatic events like the massive floods in Pakistan and India, the Hurricane Katrina in the United States, the prolonged droughts in Australia, China, Pakistan, India and Texas, are all the results of increased temperatures due to global warming. During the 21st century, climatic disasters occurred five times as frequently and killed or affected seventy times as many...