Funny stuff.

To me, arguments on both sides make sense and I actually like what Odin says, more trees certainly won't hurt us and they also "produce" oxygen which we need anyway and that's just a few of their uses, they have a lot more.
The graph about the 800 year lag Gawain showed does make sense but so does the greenhouse explanation for global warming. Another argument for global warming would be that global dimming works against it currently, because it was shown that exhaust fumes, clouds and other particles in the air reflect sunlight back to space, so reducing our emissions will also allow more sunlight into our atmosphere. This means the once we have our CO2 reduction completed and we emit nothing anymore but the atmosphere is still full of CO2, we might be grilled, or not. Depends on who is right and how strong the individual effects are and maybe that's where the truth lies.

Like many said, it's a complicated issue and a combination of differently strong factors can lead to different results. That means it's entirely possible that the earth is warming up and that we help it do so. And I wouldn't even wonder if there was a factor we don't even know about, like the reduction of cool honeybees who absorbed a lot of sunlight before and are dieing now because our waves disturb their GPS(talk about reliance on technology...).