I agree with what you said kosh271 except:
1) if the population reduction is great (say 75% or more) and the need is urgent (say 50 years or less), then birth control can not possibly be adequate.
2) if birth control is inadequate or unattainable (you said it can not come to pass in your country) then what?
None of us want to advocate killing, but the next most drastic step after birth control (and maybe the next most drastic step after that) lead us to ethically taboo places that no one is willing to discuss. That suggests that our fate is demise though inaction because all suffupicientky effective actions are too drastic to consider.
Raise this subject in a room full of activists and you'll empty the room in an eye blink. No one dares to discuss it publicly.