Greenhouse Effect and Global Warming

A report by the Australian government's Commonwealth Scientific and Research Organization (CSIRO) in the year 2006 stated that “Millions of people in Asia-Pacific region, including India, could be forced from their homes and suffer increasing disease, cyclones and floods caused by global warming ………..Chronic food and water insecurity and epidemic disease may impede economic development in some nations………………” According to the scientists these disastrous consequences of global warming will be caused by the greenhouse gases produced mainly by burning of fossil fuels such as oils and coal...

Greenhouse effect is a naturally occurring process; without which this planet would have been so cold that it would not have been able to support life as we know today. Then why is there is so much talk of greenhouse effect and global warming and doomsday approaching? Why are we talking of hotter and drier summers, water level in the seas rising drowning villages on sea coast and floods causing devastation?

Let us see what this boon of Greenhouse effect is and why it is turning into a bane!

A greenhouse is like a small glass house or a shed. It is used to grow plants especially in winter. Sun’s rays bring heat and light in through the glass roof; but the glass roof does not allow most of the heat to escape out. The glass roof not only traps the heat in but also radiates heat downward, keeping the plants warm.

Certain gases in the atmosphere we breathe also cause a greenhouse effect on the earth. Water vapor, carbon dioxide, nitrous oxide and methane form a blanket around us and function very much like the glass roof of the greenhouse. Sunlight passes through this blanket and heats the earth – land, water and the biosphere. In the normal course, the radiation from earth would have returned the energy back to the atmosphere. These greenhouse gases, however, trap the radiation; some radiation escapes the blanket but the rest of it heats up the gases. This hot blanket of gases, in turn, radiates energy back to earth.

Without this greenhouse effect energy received from the Sun would have escaped back into space and the earth would have been quite cold. The present average temperature of earth is about 14 deg. C; without the Greenhouse effect it would have been about (-) 18 deg C, much too cold for human survival. This blanket of gases keeps the earth warm much in the way greenhouse roof keeps the plants warm.

But increased greenhouse effect would raise in the average temperature of the earth with disastrous consequences. And this is precisely what the scientists have been warning the world about for a long time!