That's not even true now. Maybe individually, but looking at the big picture, even countries with 90+ percentile educations are contributing to over-population. We're too far down the line to simply promote better education. The world's resources won't last another 20 years at this rate.
This is just silly talk.
The world is nowhere near overpopulated. Slow changes in agricultural practices and power production processes has put considerable strain on the available resources in some regions - but it's nothing that cannot be solved by nuclear power and hydroponics.
The real factors that will start affecting us is oil used for transportation. We really do need to come up with more realistic solutions for transportation (current hybrid and electric concepts are cute, but horribly inadequate to address the world's need for power in transportation). There will probably be a crunch in a decade or two regarding that. Depending upon how paranoid governments and the stupid people filling those offices get...
The demand for oil and its byproducts of refinement will be very high, regardless of what is done regarding transportation. The real reason why transportation has to be addressed is because what we rely on for our modern existence comes from locations distributed across millions of square miles.
Even if just for lubricants - there will always be a demand and use of/for oil. The real issue is when food costs start skyrocketing because of transportation costs. There's still plenty of oil for another hundred years.
Anyway - if you want to control the human population, re-introduce small pox.
It was the perfect population control for humans. It's an endemic virus that survives naturally only within humans (you can get it to infect some primates if you administer them insane exposures that do not exist naturally) and has a roughly 30% case fatality rate on the whole. Regions without proper medical systems and economies are most adversely affected by smallpox.
The reason we have the illusion of overpopulation is because of smallpox. People who would have died and not survived to reproduce now do so, and have a few kids before they die. It's a cycle of self-perpetuating poverty that exists at a standard so radically below organized society yet still survives off the scraps of that society.
That's why we have the illusion of overpopulation.
Reintroduce smallpox to its natural environment and you fix the problem.
Of course - you'd collapse society, today. There aren't enough vaccines and major infrastructure would break down. Once the power goes off and the trucks stop delivering supplies (most crucially oil and coal) - it's game over. Convincing people to go to work in the face of a virus with nearly 100% infection rates and 30% case fatality rates (likely worse after the first two weeks as medical supplies and food stores become strained) ... you can see where that might be a bit much to expect.
So, there are three outcomes we can choose from.
Re-introduce small-pox and hope our grandchildren can understand why as they pick through the rubble of our industrial progress (perhaps to reclaim some of it and create an even more advanced existence from a much more varied and solid technological platform).
Create government systems to feed the rapidly expanding populations of the poor. This ultimately becomes unsustainable as the rate of reproduction of these groups will rapidly exceed that of those who are being taxed. Despite the intent of the program - not enough people leave the 'safety' of the programs and continue to produce offspring dependent upon the program. Hyper-inflation ensues and our grandchildren will be picking through the rubble of our society.
Not feed the starving people. Millions will die due to lack of basic needs - but current society will be able to continue for a considerably longer period of time. We have merely eliminated smallpox as a selective force and have allowed it to default to that of exposure.
Ah, the path to hell is lined with good intentions.