From all the news about how anthropogenic emissions of CO2 are increasing tremendously (remember the hockey stick graph?) you would think that these emissions are causing all the atmospheric increases of CO2. And, our use of fossil fuels is increasing exponentially, with more than half of all fossil fuels ever used by humans being consumed in the last 20 years.

However, in comparison with the amount of carbon that enters the atmosphere from natural sources, our fossil fuel emissions are modest. “Carbon dioxide generated by human activities amounts to only a few percent of the total yearly atmospheric uptake or loss of carbon dioxide from plant life and geochemical processes on land and in the ocean,” said Gregg Marland, a professor in the Geology Department of Appalachian State University, Boone, North Carolina. “This may not seem like much, but humans have essentially tipped the balance.”