Originally Posted by ENINTY
Dude, it was a joke; but actually they do. Depends on how you look at the cycle of carbon in the environment.
Sure, but the CO2 debate as I understand it is centered largely around the argument that we have had plenty of it for eons without the need to have machines producing it. I.e. - in very rough and simplified form - animals process oxygen and emit CO2, while plants process CO2 and emit oxygen. All the excess CO2 that is the product of the modern industrialized world, then, is what is claimed to be the major issue ("too much of a good thing is a bad thing").