It is, in my opinion, the proverbial elephant in the room. Unfortunately, the issue is more political than environmental, hence, out of control.
There used to be a saying that "it's all about the economy", and for far too long now, the growth model. Government interference has rendered this model corrupt and destructive.
More people, more cars, more pollution, more waste, less trees, less clean water, less space to breathe.
In the developed world, the populations are ageing, and not naturally regenerating, but there are obligations to social programs, so mass immigration is the tool being wielded to stave off financial crisis. The bloated system needs more and more taxes and more and more people to survive, so defecits are run and debt accumulated as if there is no choice.
When the financial crisis hit recently, the goverments took trillions of our dollars and threw it at the problem. The banks had to be kept alive to keep business alive to keep people employed. Otherwise, some said, a severe economic depression would have put already vulnerable economies to bed, and mass social turmoil would have ensued. People would be out of work, governments would be out of money to help them, and all hell would break loose.
But we're already there, the lords of government and their media preachers keeping us shrouded and enslaved in lies and dependance.
Why are people in developed economies having shrinking families, and those in underdeveloped countries sustaining and growing?
If the current economic model is valid, would not the reverse be true? Would not those who were truly prosperous be enaging in the ultimate joy of family?
Is wealthy with few children better than poor with many?
Which god gave oligarchs the power to determine survival?
The solution to overpopulation is to stamp out government control of things, especially economics, and particularly in the propping up of the wobbly.
These growth-model/welfare state economies must be left to fail, wars must be fought, and in the settling dust, we can get back to the basics of helping ourselves and each other without the dirty heavy hand of government.