Advantages of Greenhouse Effect
Before we delve into this topic let us understand the green house effect first.
The primary greenhouse gases in Earth’s atmosphere are water vapour, CO2 and Ozone along with other gases like methane, CFC’s or chlor-fluoro-carbon and nitrous oxide.
These gases are rather inefficient absorbers of solar radiation and thus allow much of the incoming solar energy to pass through the atmosphere to heat the Earth’s surface.
They are good absorbers of the long wave IR radiation that is reflected from the surface.
A proportion of outgoing energy absorbed by these gases is re-radiated back toward the planet producing an additional warming of the troposphere and Earth’s surface. This is better known as greenhouse effect.
The present day greenhouse warming is estimated to be 33oC.
The greenhouse gases in the Earth’s atmosphere therefore raise the global mean temperature of the surface from freezing point of water to a comfortable level of around 15oC.
The presence of greenhouse gases in the Earth’s atmosphere has therefore been essential for habitability.
The amount of CO2 and other greenhouse gases in the atmosphere have varied significantly over the years, but the mean global temperature has not varied greatly in last few billion years.
The presence of equable temperatures has enabled life to evolve on Earth and has in a way contributed to maintain the overall global temperatures within limits.
Advantages of Greenhouse Effect:
(a) Unlike other planets this planet is able to sustain life is because the greenhouse effect has maintained the temperatures within a manageable limit.
(b) The greenhouse effect also helped maintain the water balance in all the spheres of this planet.
(c) The greenhouse effect has helped in restricting the polar caps in Polar Regions only.
(d) Increase in greenhouse gas may also lead to melting of northern ice regions to thaw and thus make it habitable.
(e) Due to the greenhouse effect and an increase in the moisture level in atmosphere, rainfall is possible in regions where it was un-imaginable before.
(f) Agriculture is now possible in regions which are primarily arid or semi-arid zones and better agricultural practices where cropping is completely dependent upon rain water harvesting.
(g) The overall greenhouse effect also in a way helps in extending the growing season of crops and so many crop products or vegetables are now available beyond season.
(h) Both growing and flowering in plants are completely temperature dependent and thus with prevailing average temperature along with the presence of humidity in high percentile help plants to grow and yield better than before.
Let us not forget that the greenhouse bad effects are quite large compared to greenhouse effect benefits and thus it is always better to control the greenhouse gases within safe limits before it is too late for the mankind to survive in earth system.