Rock on, by, rodward and maverick.
A few points, and I'll try to keep my ranting under control, as I feel I've been posting a lot recently on things that are only vaguely word-related.
As to greedy South American farmers: does wanting to eat make one greedy? These folks are not sitting back on the verandas of their great haciendas and enjoying seeing the great towers of new-cut hardwoods stack up for shipment abroad - for the most part, they're clearing a couple of acres and planting the crops they plan to eat. In general, they've no other option, and there's a lot of them.
On carbon sinks: one of the most likely explanations for the lower-than-expected presence of carbon in the atmosphere is that the world's oceans are absorbing a lot of the CO2 we generate. What no one knows is how much they can absorb, and what happens when they reach that limit: do they gradually absorb less and less, do they just abruptly stop absorbing it, or do they reach a point of super-saturation and just start spilling carbon back into the atmosphere? In either of the latter 2 cases, we're in big trouble fast.
I agree with belligerentyouth, the earth will withstand whatever we can do to it. So, we won't kill the planet - just ourselves. I've got a baby due tomorrow, and I can't live with that.
[/eco-rant]
