responding to "question?"
any individual CO2 molecule will eventually be removed from the atmosphere by being incorporated into a plant, absorbed into the ocean, or incorporated into soil or a carbon-carrying rock. Because plants die and decompose, however, there will always be some amount of CO2 in the atmosphere, just as there was CO2 in the atmosphere before we started burning coal in the industrial revolution. even the CO2 absorbed into the ocean or turned into rock isn't permanently there; dissolved CO2 in water is in equilibrium (surface-water, anyway) with the CO2 in the atmosphere above it, and rocks eventually erode.
the key is equilibrium and rates. we are currently releasing CO2 into the atmosphere more rapidly than the oceans (and other sinks) are absorbing it. this is leading to an increase in the concentration of CO2 in the atmosphere. If we stop releasing CO2 from fossil sources tomorrow, the concentration of CO2 in the atmosphere will gradually decline over the next several decades or centuries and will eventually return to (roughly) pre-industrial levels.
regarding fossil fuels, they are made from carbon that was once atmospheric. plants absorbed the CO2, died, and were buried before they could decompose; it was that carbon burial that lowered the CO2 to the levels the earth has seen for the past several million years--the earth was hotter and seas were higher back when the coal and oil we are using today were plants.
most of what I said doesn't require citations. it's common sense or basic science. here's a cartoon of the carbon cycle:
http://www.exotichide.com/G/ipcc.gif
the statement about equilibrium and rates can be backed up any of the "increasing CO2 concentration" studies, for instance this one:
http://www.esrl.noaa.gov/gmd/ccgg/trends/
my last paragraph could be considered slightly more controversial. one point, that the earth has been warmer than it is now, is easy: look at the eocene period.
http://en.wikipedia.org/wiki/Eocene
the connection between carbon burial and cooling is tougher; i don't have a citation for that. anyone else?