The problem, of course, is not in the fact that clearing Carbon CO2 emissions from the air. It's the fact that it might be worth more - in dollars - to cut those trees down and sell them. Perhaps not in this case, but certainly in other cases where countries have tried to sell protecting their own territory environmentally and balanced that against the worth of the resources on the market.

Thus the dollar worth of clearing CO2 emissions doesn't clearly align with the self-interest of doing so over buying trees to make paper and other goods. (The self-interest, of course, is in not dying in the future from some climate change related disaster.

That's why worldwide governmental intervention is needed to make sure the dollar value of keeping those trees up aligns with actual self-interest.