Its not unreasonable to ask for few facts to back up this key assertion.
How much more carbon today than, say, thirty years ago?
We actually used to do that (black soot) but we stopped...unlike China and India, whose clouds of pollution can be seen from space.
The black residue lands on ice packs and actually causes melting.
"Most of the earth's land mass is located in the northern hemisphere, as is most of the earth's vegetation. During autumn and winter, millions of tons of leaves fall fall from deciduous trees and as they decompose, they give off carbon dioxide. The trees themselves no longer process as much carbon dioxide as they are in somewhat of a dormant state. As a consequence, the earth's carbon dioxide levels rise.
Throughout the spring and summer days, leaves grow rapidly and a great deal of carbon dioxide is consumed in the growing of the leaves and subsequent normal respiration processes - so the CO2 level drops."