bad day posted:

I have been toying around with a story that involves a character wiping out a large part of the human population to save the environment. This isn't a new idea - it's spawned a James Bond movie and a Batman villain - some people think it's a real thing, even.

But I'm at a loss as to how someone would realistically accomplish the goal. Most of the ideas conspiracy theorists have (chemtrails, vaccines, mass sterilization, etc) are kind of unexciting. You wouldn't want to irradiate the earth or harm its long-term ecology, but you'd want to get rid of approximately a third of the earth's population. Somehow. My best idea involves dropping giant rocks from low earth orbit onto major population centers.

How would you destroy civilization, given such a mandate? What are the pluses and minuses of different scenarios?