Global Warming!!!

 Lets see...Most of you must be knowing why global warming is caused..but i will go on and give a gist of it...

Gases such as Carbon dioxide , Methane etc let short wavelength infrared radiation pass through the atmosphere ( heat from the sun ) but contain long wavelength infrared radiation ( radiation emitted by earth (or any object) after heating up) , basically it acts like glass lets heat in but doesn't let it out.Hence these gases are called Greenhouse gases since its behavior mimics a Greenhouse.

Now it can be understood that as the concentration of greenhouse gases in the atmosphere increases the temperature of earth increases. So bascially our major job is to decrease the concentration of greenhouse gases and the planet can be saved??? No, there are two more major factors which enchances the global warming effect , basically these are positive feedback loops i.e. the input is dependent on the output positively,the more the output implies more input which further implies even more output and so on.

Positive Feedback Loop 1:
Now the north pole and the south pole are the two places which receive continuous 24 hr sunlight during the summer and the winter respectively.Antartica is basically a big mass of ice and the arctic ocean is almost always covered by frozen sea ice. Now these ice act as mirrors and reflect 99% of incident radiation back to space , unlike water which absorbs most of the incident radiation.
Hypothetically if both the poles did not have ice , then the solar radiation (heat) would have been absorbed by the sea , its temperature would increase which would eventually increase the average temperature of earth. (since oceans cools the land , all the trade winds etc originate from the oceans).

Okay... now what is happening is that Greenhouse effect is increasing the average temperature of earth.This causes the ice in the polar caps to melt which in turn reduces sunlight reflected by ice and increases the sunlight absorbed by water.This in turn increases the temperature again.As u can see this is the positive feedback i was talking about. Ice melts->water absorbs sunlight->temp increases->ice melts.

Thankfully for the above positive feedback to become self sustaining there has to be an initial threshold.

The initial threshold maybe the average temperature or the amount of ice left on Antarctica.It could be  anything and we have no way of finding out (scientists are running advanced weather models to find out the exact threshold and have been unsuccessful till now). Once this happens consider our planet's climate system would go out of control.
Okay now on to the second feedback loop..

Positive Feedback Loop 2:
We all know that most of Greenland is covered with ice. But underneath that ice are massive reserves of Methane ( Natural Gas ). Now as the ice melts, methane leaks out into the atmosphere.As you know Methane is one of the major greenhouse gases.Again a positive feedback loop has uncovered itself.

Ice melts->methane leaks->green house effect..temp increases->ice melts->and so on

Hence Global warming is a result of Greenhouse effect and the two feedback loops mentioned above

Our present carbon emission rate + both the positive feedback loops.We are looking at an avg increase in 2 to 3 degree from a optimist's view and an increase of 6 degree's from a pessimist's view in the next 10-20 years.

So i suggest all of the readers to GO GREEN!!

P.S. About the methane leaking thing, there are several videos of it. Scientist's light the jet of methane leaking out of ice (:D).Looks really cool , check it out on youtube. :)