The primary cause of global warming is the rise of carbon dioxide levels in the atmosphere. On one hand, carbon dioxide levels are increasing rapidly because of human activities. On the other hand, carbon dioxide gas has a long life cycle, as much as 100 years,
Which adds to the problem? When there is the right amount of carbon dioxide in the air, it maintains the planet’s temperature by trapping the infrared radiations coming from the Earth. But when the concentrations of carbon dioxide are high, the result is the rise of the temperature of the planet above normal. This is called global warming. Therefore, the greenhouse effect has a direct impact on global warming.
The right level of carbon dioxide in the atmosphere maintains global temperature at a level required by life to be maintained on the planet. If it was not for the carbon dioxide concentrations, the planet would be a very cold place to live in. But because carbon dioxide levels are rising at a high rate, they are causing global temperatures to rise by 0.4 – 0.8 C per decade, which is resulting in global warming.
Harmful effects of global warming:
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There are a number of problems that the world is facing and will face due to global warming:
i. The effect of global warming is to increase the average temperature of the Earth. A rise in Earth’s temperature will lead to other alterations in the ecology. The sea level would increase and the quantity and pattern of rainfall will alter. These alterations will lead to severe climatic conditions like floods, famines, heat waves, tornadoes and twisters.
ii. It is causing warming up of regions. Due to global warming various new diseases have emerged. These diseases are occurring frequently as bacteria can survive better in warmer conditions and multiply faster. It is said that malaria has not been eradicated at a number of places because of global warming.
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iii. Global warming is raising the temperature of water in the oceans. This results in environmental phenomenon like hurricanes. And as temperatures of the oceans rise, they will lead to more forceful and frequent hurricanes.
iv. There will be a severe shortage of water because of warm temperatures, which is a matter of concern in the future.
v. All of these above impacts will lead to economic problems. More money will be spend during times like hurricanes and during break out of diseases. It will also cause shortage of food, leading to severe economic crisis.
vi. Global warming is already causing melting of the polar ice caps, which is leading to a rise in the sea levels. Some low-lying areas will be submerged. When polar ice caps melt, the water thus formed will go into the oceans and decrease the salinity and disturb currents in the ocean.
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vii. Global warming will lead to disappearance of different terrestrial and marine flora and fauna.
viii. The coral reefs are expected to die off as an effect of global warming.
ix. It will change the global weather causing shortening of winters, more dry weathers, and an increase in heavy rainfall.
El Nino:
During winter time, the equatorial waters in the Pacific flow southwards, due to periodic changes in atmospheric pressure over the tropical Pacific regions. This periodic flow of warm equatorial Pacific water has been termed as El Nino. El Nino causes disruption in weather patterns, mainly along the Pacific coast of South America, though its effects on weather are felt all over the world. These effects include drought in Australia and Papua New Guinea, storms and threat of floods on Pacific coast of Central and South America and delayed monsoon in South East Asia.
Between 1900 and 1995, El Nino occurred once in every five years. However, studies show that El Nino is now occurring every three years, with increasing severity. Heat-trapping greenhouse gases in the upper atmosphere lead to global warming, which in turn has increased the frequency of El Nino. This will have severe socio-economic impacts, since many developing countries depend on their agricultural and fishing sectors for food and employment.