Michael R. Fox, Ph.D., puts man-made CO2 in context:
Then there are several key gases which combine to be called greenhouse gases (GHG). About 97% of the greenhouse gas inventory is water vapor. Given that 70% of the Earth’s surface is water, we shouldn’t be surprised. The next most prevalent GHG is CO2 which is about 1.9% of the total. There are lesser amounts of methane, and others making up the rest. The CO2 fraction is only 1.9% of the total. However, the man-made fraction of the total CO2 is even smaller, less than 3% of that 1.9%, or 0.06%.
Thus, another problem arises for the “global warmers”. They are left to explain why the tiny manmade fraction of CO2 is a warming problem but the much larger fraction of CO2 from natural sources is not, since the CO2 from both natural and manmade sources are chemically identical.
It is quite possible the only way to stop global warming, based on the theory that it is caused by CO2, is to drain the oceans.