Similarly, one of the most obvious causes of increased carbon emissions is mass immigration from the Third World to the First World (e.g., from Mexico to America). So, more stringent restrictions on immigration would be an obvious policy implication.
Somehow, though, I don't think Al Gore has ever gotten around to mentioning either of these bits of logic.
If Global Warming is such an all important topic, then surely these simple steps for mitigating it should be on the table, surely. And yet, they just never seem to come up. It's not so much as that they've been rejected as that they simply are, literally, unthinkable.