Belz...
Fiend God
The idea that the problems of the world can be solved by somehow "removing" a percentage X of the total population show an astonishing lack of grasp of the power of exponential growth.
If tomorrow we turned half of all humans on earth into Solyent, we would be exactly were we are today in about 2060, given normal birthrates.
Well obviously my plan involves 2-child limits and colonisation of other planets!