*sigh...* Damn you people are thick sometimes... do I have to spell everything out for you? I will grant you that CO2 levels are indeed higher because of deforestation... plants to indeed filter CO2 from the atmosphere. Interestingly, here is a paper that suggests the other aspects of massive deforestation could have a net cooling effect.
http://www.pnas.org/content/104/16/6550.full.pdf+html So, deforestation (while bad for plenty of other reasons) may not be contributing as significantly as you may have thought.
What I was alluding to, however, was the fact that human CO2 emissions are orders of magnitude higher than natural ones. Even without deforestation, we would still be pumping billions of metric tons of CO2 into the air that would throw off the Earth's natural carbon cycle. The carbon cycle (that over the past 800,000 years or so has been in a fairly solid equilibrium) would have to find a new equilibrium because of our inputs.
I have to run and catch a ferry... I have much more to say in response to some of these latest posts...