Although I tend to doubt that this is what he advocated, it would be a terrible idea in any case. Killing 90% of the human population would actually cause grea

Although I tend to doubt that this is what he advocated, it would be a terrible idea in any case. Killing 90% of the human population would actually cause greater ecological catastrophe in the long run. Society is, albeit slowly and unevenly, modernizing and becoming wealthier. This means that population is projected to peak around 9-10 billion (UN figures) and begin declining before the beginning of the 21st century. As technology improves, we might eventually reach a point of relative stability, where we can satisfy nearly all material desires (I believe they are finite, though immense) with a stable population, and I'd imagine that this is likely within a few centuries. This, of course, requires that we don't destroy ourselves or the earth first, but I'd give us a better than 50% chance. All bets are off, though, if we conquer death and aging and still have the desire to procreate-- then we pretty much have to colonize other planets-- but I'm not terribly worried about that one. Killing 90% of the earth's population in such a way would result in a cycle of chaos and turmoil that would leave humanity in an utterly wrecked state, especially after the revenge wars that would ensue against those responsible (or blamed) for the plague. The state of humanity would be set far back, and we'd have to go through these ecologically net-negative phases of development again.