WASHINGTON -- GLOBAL WARMING is “unequivocal,” according to the just-released report by the Intergovernmental Panel on Climate Change. The most likely culprits are people — all of us. Yet, apart from insightful comments by former Vice President Al Gore, there has never been much public discussion about the role of human population growth in global warming. Prof. Tim Dyson, of the London School of Economics indicates that a 40 percent cut by 2050 in per-capita carbon emissions in the developed world could be completely cancelled by population growth. It’s time to open a “second front” in the battle against global...