First, we've got population. The world today has 6.8 billion people. That's headed up to about nine billion. Now, if we do a really great job on new vaccines, health care, reproductive health services, we could lower that by, perhaps, 10 or 15 percent.
https://www.ted.com/talks/bill_gates_innovating_to_zero/transcript?language=en
Hmmm. If only we had the technology to move water from one location to another. Nah let's just kill everybody so they don't starve.
Seriously though, if you want to reduce the population of developing nations, just stop sending foreign aid and interfering with their economy/culture. These populations are dependent on a level of technological and cultural maturity that they did not earn and cannot maintain.
Here’s an idea. We round up every celebrity and place them in involuntary lockdown for one year. It’s okay, celebrities, it’s not a violation of your rights because it is for the greater good. For one year we take away every celebrity’s phone and access to communicate with the outside world. Meanwhile the rest of us non-celebrities continue life normally. Then, after a year without celebrities, we see if anything has improved in society. If world harmony has increased by even one tenth of one tenth of one percent, then we continue the involuntary celebrity lockdown for another 15 days* for as many years as we like. And by “celebrities” we include anyone who is recognizable to the general public by face or by name: actors, musicians, athletes, journalists, politicians, CEOs, etc. They are already on board with this concept of the greater good so there shouldn’t be any pushback there, and I think even BLM and Antifa would be with us on this.
Even better: If "just one child is helped" then it justifies anything, right?
"...non-celebrities continue life normally." Great idea. Non-celebrities, however would have to be living life normally, first. We are not.
Best way I've hear it stated.