Write a short note on the effect of Global warming and Greenhouse effect on environment. 

About $75 \%$ of the solar energy reaching the earth is absorbed by the earth's surface, which increases its temperature. The rest of the heat radiates back to the atmosphere.

Some of the heat is trapped by gases such as carbon dioxide, methane, ozone, chlorofluorocarbon compounds ($CFCs$) and water vapour in the atmosphere. Thus, they add to theheating of the atmosphere. This causes global warming.

In cold places flowers, vegetables and fruits are grown in glass covered areas calledgreenhouse.

We are surrounded by a blanket of air called as atmosphere. This atmosphere kept thetemprature on earth constant. But now slowly it is undergoing change.

Atmosphere traps the sun's heat near the earth's surface and keeps it warm. This is callednatural greenhouse effect because it maintains the temperature and makes the earth perfectfor life.

Carbon dioxide molecules also trap heat because they are transparent to sunlight but not ableto trap the heat radiation. If the amount of $\mathrm{CO}_{2}$ crosses $0.03 \%$ the natural greenhouse balance

may get distrubed. Thus, $\mathrm{CO}_{2}$ is the major contributor to glogal warming.Besides carbon dioxide, other greenhouse gases are methane, water vapour, nitrous oxide,

$CFCs$ and ozone.In the absence of oxygen if the vegetation is burnt, digested or rotted, than methane isproduced. Large amount of methane is produced. Large amount of methane are released inpaddy fields, coal mines, from rotting garbage dumps and by fossil fules.

Chlorofluorocarbons ($CFCs$) are man-made industrial chemicals used in air conditioning etc.

$CFCs$ are also damaging the ozone layer.Nitrous oxide occurs naturally in the environment. The quantities of nitrous oxide increaseddue to the use of chemical fertilizer the buring of fossil fules.

If these trends continue, the average global temprature will increase. If may lead to melting ofpolar ice caps and floodin of low lying areas all over the earth. Increase in the globaltemperature increases the incidence of infectious diseases like dengue, malaria, yellow fever,sleeping sickness etc.