Fewer kids = greener?

I love reading well-written arguments from different sides of the global warming polyhedron.

First: Contraception Fights Global Warming from Salon.com

Second: The Population Myth from Monbiot.com

Personally, (and, I confess, as someone who has no plans to procreate) I found the Salon article quite convincing at first, but was wondering how the numbers stacked up. It was reaffirming to read George rightly pointing out that the groups experiencing the largest population growth are normally the ones who contribute the least per capita to carbon emissions.