A letter to the editor of the Austin American-Statesman, published on December 23, 2009, asks this question: "The trillion-dollar question that Copenhagen has not answered [is this]: Because carbon dioxide molecules arc all identical, why is it that carbon dioxide from carbonated beverages, pets, cattle, farm animals, and humans, yeast, dry ice, fireplaces, charcoal grills, campfires, wildfires, alcohol and ethanol is good, and carbon dioxide from fossil fuel is bad? Can anyone in the United States answer this question?" What is your answer? Your aunt asks you how we know that volcanoes arc not responsible for the observed increase in carbon dioxide. What do you tell her?

It's very simple. We all know that the property of a compound never change no matter what the source of that compound is. In case of carbon dioxide it's also the same. Yet, there is one huge difference in emissions of carbon dioxide. The amount of carbon dioxide emitted from all the other sources other than that of fossil fuels is several hundred times less as compared to that of condensed fossil fuels. That's the reason fossil fuels contribute the most in the overall emissions of carbon dioxide all over the world.

The answer is same from volcanic arcs because no volcano is able to emit carbon dioxide amount that is near compare to that of fossil fuels. Furthermore, fossil fuels are burned regularly throughout the world while volcanoes may erupt just a few times in a century.