Don't you think Peak Oil is worse in the sense that its effects could clobber the affluent denizens of the globe much sooner than the effects of Global Warming (as opposed to the impoverished majority of the planet, who are already suffering due to both Global Warming and Peak Oil in any case)?

Yes, I agree with this. GW will play out over the century -- PO will play out over the next few decades, and in terms of war is already playing out.