Prince Philip: The growing human population is the biggest challenge to conservation.

Interviewer: "And do you have views about what should be done about that?"

Prince Philip: "Can't you guess?"

Remember, this is the man who said—in a 1988 interview with Deutsche Presse-Agentur: "In the event that I am reincarnated, I would like to return as a deadly virus, to contribute something to solving overpopulation."

He also told People Magazine: "Human population growth is probably the single most serious long-term threat to survival. We're in for a major disaster if it isn't curbed—not just for the natural world, but for the human world. The more people there are, the more resources they'll consume, the more pollution they'll create, the more fighting they'll do… If it isn't controlled voluntarily, it will be controlled involuntarily by an increase in disease, starvation, and war."