Global Warming means the rise in the global temperature to a level which affects the life forms on the earth surface. The earth’s climate is driven by solar radiation. In the long term the energy absorbed from the sun must be balanced by outgoing long wave thermal radiation from the earth and the atmosphere. But part of this outgoing energy is absorbed and re-emitted by some atmospheric gases, there by reduction in the net emission of energy to space.
These gases are known as green houses gases and theirs effect is known as green house effect. The increase in the quantity of the green house gases in the atmosphere can reinforce the green house effect and lead to global warming. The main green house gases are water vapour, carbon dioxide, methane, nitrous oxide and ozone.
There are also purely man-made green house gases, including many ozone depleting substances such as CFC, carbon monoxide, nitrous oxide. CFCs and nitrous oxides are more potent green house gases than the same quality of carbon dioxide and methane. The largest sources of methane in the atmosphere are natural wetlands, rice paddies and livestock.
Apart from these natural gas production biomass burning, landfills and coal mining also releases methane. Nirous oxide is another important green house gas released by the oceans; solis etc. but human activities such as bio-mass burning and use of chemical fertilizers play a major role.
However amongst all green houses, carbon dioxide is the largest sources of the green house effect as it holds the largest share among the green house gases. According to the report IPCC for climate change, 72% of global warming contributed by C02, 18% by methane and 9% by nitrous oxides.
IPCC has also mentioned that carbon dioxide, methane and nitrous oxide have increased considerably as a result of human actions since 1750 and now far exceed pre- industrial values and the primary source of C02 increase is the use of fossil fuel. This would have quite adverse effect on climate.
For decades scientists have studied the climatic effects of green house gases. The effect of the global warming process will be felt on several sectors like agriculture, fisheries, forestry which would ultimately affect the economies of countries.
The inter governmental panel on climate change has predicted a shift in the current agricultural production pattern, changes in the ground water availability, increased occurrence of climate extremes, crop diseases etc.
A rise in sea levels as a result of melting of ice from the poles will also threaten low lying costal areas. Health experts also expect a rise in the climate related diseases such as heat strokes and a spread of vector borne diseases such as malaria, filarial, dengue etc.
Others have also warned about the consequences of increased water shortages. The economic consequences of such changes may be immense. It is estimated that an overall damage of economy due to global warming would be a quarter percent of world GNP.
Solutions for Global Warming: The most important contributor to global warming is the increase in the atmospheric C02 level due to human activity. The following steps may be taken to prevent the global warming. C02 emissions can be cut by reducing the use of fossil fuels’ by cutting back on car use, investing in energy efficiency, implementing energy conservation measures, utilizing renewable sources of energy such as wind, solar, and hydropower. Reducing fossil fuel use will also reduce emissions of methane, nitrous oxide and ozone.
i. Since C02 is consumed by plants and hence planting more trees will play a unique role in the global carbon cycle.
ii. Government should also encourage the use of mass transit; provide tax rebates for people who buy low and no-pollution vehicles.
iii. Try to cut down the use of electricity
iv. Green house gas emissions be managed by using an incentive based policy, such as market based approach to capping and reducing such emissions.
v. By following the environmental policy of Reduce, Reuse – and Recycle.