One of the problems with thinking about depopulation is that there are so many variables involved. These include:
How many resources does the world actually have?
How are you supposed to go about answering this question? Say you manage to figure out how much food the planet can produce given current agricultural methods those methods may change, or it may be found that those methods cause serious cumalitive damage. Such damage that results in diminishing food as time goes on. Though I haven’t done any research I’m willing to bet that there are many figures concerning this variable all of which support many mutually exclusive opinions and lead to very different opinions concerning over-population.
The rate at which population increases.
Is this a constant value? Does the human population rise and fall independent of resources? I may have cast us as a kind of phage, something that will expand given more and more resources but on what ground did I make that statement? No ground apart from a memory of school and the food pyramid. You know that schema that says that if there’s a tonne of carrots there will be a tonne of rabbits but if you decrease the supply of carrots the rabbit population decreases. Which seems convincing but does it apply to humans? Is it even true of the rabbits? I mean what were the experimental procedures used to gain this knowledge? How are we to assess such procedures? How are we supposed to trust the people performing the experiments? Keep an eye out for the number 27 and tell me how times you notice it tomorrow!
Isn’t it possible that the human population could increase and decrease cyclically over time?
Probably the worst thing of all about this issue is that the means are not available to any one person to verify any of the positions. It reminds me of the evolution vs creationism debate. Now personally I don’t know which one is the case. I have read books by proponents of both views and been convinced by both sides. To actually verify it or become properly informed about the issues would take a lot of effort which I can’t expend on it because it doesn’t hold my attention.
But even so the means required to verify either case are not in the hands of the normal man. What it comes down to is a kind of hooliganism! Who do you support the atheists or the theists? In much the same way here it comes down to which sources of opinions you support: those preaching depopulation or those preaching expansion!