New York Times: If we wanted to bring about the extinction of the human race as quickly as possible, how might we proceed? We could begin by destroying the planet's atmosphere, making it incapable of supporting human life. We could invent bombs capable of obliterating the entire planet, and place them in the hands of those desperate enough to detonate them. We could bioengineer our main food sources - rice, wheat and corn - in such a way that a single disease could bring about catastrophic famine. But the most effective...