### Number Watch Web Forum

This forum is about wrong numbers in science, politics and the media. It respects good science and good English.

Number Watch Web Forum
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co2 and World Population growth

Since about 1880 to present the co2 in the atmosphere has gone from about 280ppm to about 380ppm. During that same time period the Earth's population has increased from about 1.4 billion to about 6.4 billion. Since we exhale co2 with each breath and there are about 5 billion more of us; I am wondering how much we have contributed to the co2 in the atmosphere. Gary K.

Re: co2 and World Population growth

No dice - all the carbon in us comes from the pool open to the atmosphere - we are just a carbon sink, locking up a few kg for a few score years. In problems like this, simplify the issue - you are a box full of C. what C you emit by breathing must come from somewhere - food, which comes from CO2 + hv + H2O. Net (at steady state) change on atmosphere = 0. Not quite steady state (more people) -> 5*10^9 people *4kgC/person (ish) = 2*10^10kg = 2Mton C locked up more than before.