Tuesday, July 14, 2009


Global Warming due to increasing concentration of greenhouse gases is a serious threat to our environment.

This is a problem which demands concerted action of almost everybody on planet earth. Countries all over the world are working United Nations Framework Convention on Climate Change to tackle the issue. The present protocol in place for all nations is Kyoto Protocol which, in a nutshell, prescribes emission limits for each country. Kyoto Protocol, however, had only limited success in bringing up required action from all over the world. In coming December UNFCC will hold a Climate Conference in Copenhagen, Netherlands where the next protocol will be finalized.

As far as global warming is concerned, unfortunately, most of the people are still unaware of the gravity of the problem. Many of us still don't feel that it’s an issue demanding urgent action. Countries like India and China many a times do nothing but blaming developed countries.

Here is a primer for those who want to understand the graveness of the situation.
To understand global warming, one just needs to understand following two key figures and the relation between them
  1. Emission rate of CO2, generally expressed in billion tons per annum
  2. Atmospheric concentration of CO2, generally expressed in parts per million by volume (ppm)

Once CO2 is emitted into the atmosphere, the only sinks available to it are oceans and terrestrial ecosystems. A limited amount of CO2 will be absorbed there to complete the carbon cycle. The remaining CO2, however, remains in the atmosphere as an inert gas for hundreds of years. Thus if the amount emitted is greater than that absorbed, the concentration of CO2 goes up. The oceans and terrestrial ecosystems have historically slowed the rise of atmospheric CO2, absorbing more than half of the carbon that has been emitted into the atmosphere since the start of the Industrial Revolution.

As shown in the above figure CO2 emissions have gone up five times in last six decades. And in ‘business as usual’ they will keep on increasing to reach unprecedented levels. The capacity of CO2 sinks to absorb CO2 will definitely go down or at best remain at its current level in the near future for obvious reasons. Thus atmospheric CO2 concentration will go up at increasing rates.

Now look at the above figure which shows atmospheric CO2 concentrations for last four lakh years. As expected the value has shot up since Industrial Revolution. The present level is at 385 ppm. Each ppm of CO2 corresponds to 2.1 billion tons of CO2. Thus with present emission levels at 8 billion per annum, the concentration is going up by 3.8 ppm per year.

Even with present concentration of 385 ppm, average global temperatures is rising, causing number of observable effects like melting of glaciers. So what is the safe concentration level? Till now it was widely regarded that level of 560 ppm will trigger sever climate changes. However, a recent study claims that “if humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted” we can’t have more than 350 ppm (that’s where the title come from) CO2 in the atmosphere.

Now personally I have doubts accuracy of these predictions for the simple fact that nobody has ever observed what happens under such conditions. At the same time, however, shear imbalance in generation and sinking rates of CO2 leading to monotonous rise in CO2 concentration levels, average global temperatures, and rising ocean levels is sufficient for me to believe that something is going wrong. Ecosystems generally operate in equilibrium without such monotonous changes in any of its variables. Studies cited above give much needed support for such intuitive feelings.

Unfortunately, most people around us, including our representatives and leaders, are unaware about all this. Most probably they are not aware about the gravity of the situation. Now what can one do if she fully understands the situation? I think, as a global citizen it’s our duty to convey our feelings to all those who are going to decide the action plan of entire humanity. We cannot just seat back and hope that our representatives and leaders will take appropriate action. We have to tell them that we do care about our environment and you better take our feelings in consideration.

How can we do this? That’s a question with no single answer. Here is an article by Bill McKibben in Resurgence where he explains plans of his organization, 350, to spread the message. In my opinion activities like these will be very effective in spreading the message. I would surely like to be a part of some 350 action on the United Nations Day and be a part of a global movement.

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