Some thoughts on finite CO2-absorbing capacity: - If these forests are sustainably logged, we can take some of the carbon out and sequester it in buildings (or even just bury it), allowing the forest to regrow and absorb more carbon. - I have a theory that presently discussed global climate change solution only needs to buy us a maximum of 100 years, and by then our tech for dealing with silly problems like excess carbon will have almost surely advanced beyond recognition. Given rates of progress in chemistry, physics, and materials science over the last two centuries, this isn't crazy.