Once a population reaches a certain material standard of living the birth rate in that population falls. Your great, great grandfather very likely fathered a dozen children. Today, in the west, we don't. Indeed our population is falling. You can put aside all the individual motivations and rationalisations. The fact remains, once a population reaches a certain material standard of living the birth rate in that population falls. The solution to global population growth is largely one of raising living standards. Once that is achieved the proper application of biological controls will follow, as night follows day, and the birth rate will fall. This is what makes the issue a political and economic one. I am sorry your education is too limited to appreciate this important point. If you are still in your teens, that is understandable. If you are in your twenties, that is unfortunate. If you are in your thirties, that is unforgiveable.