Genghis Khan was a genocidal criminal

[walrus]

Don't be silly. The locals were squabbling and because might makes right he had to kill everyone. Plus they had no healthcare and would have died anyway. Lyle says so.

I think he thought cutting down the population would reduce global warming as well

[Gandalf]

I agree with that one. Genghis was clearly a philosopher as well as genocidal maniac.