Forgot to say: one of the EBay sellers includes this in his pitch, which I think is the key to the entire thing:
"You can continue living the way you always have." So, to sum up, send him money, he plants a tree, you go about your business as usual.
I don't have to buy carbon credits from algore's company, I already bought them from a bunch of guys living under a bridge. They don't need them because they have no houses or cars or jobs. All I had to pay was a couple of cases of beer. Some bargain eh?