Possibly the best thing that could be done for humanity in the next hundred years is to solve the lack of empathy for individuals and groups of people we have not met. I think if you had some friends in Africa that would be affected by your solution, you would feel very differently.
I am not picking on you here--I think this is a failing in the way we're wired that some part of us (including me) can consider tragedy at that scale as a possible solution.