I do not understand how anyone takes seriously the claim that the world is overpopulated. The current estimated world population is roughly 6.8 billion people. If you gave each person 5 square feet of space for standing room, you could stand the entire population of the world within the boundaries of Rhode Island, the smallest state in the United States of America (Rhode Island is 1,214 square miles in size, which works out to 33,844,377,600 square feet).
If you broke the current population of the world down into families of four, you would have approximately 1.7 billion “families.” If each “family” were given 1.4 acres of land upon which to live, you could fit the entire population of the world in Canada with room left over (there are 43,560 feet in an acre, Canada’s area is 3,854,085 square miles, which works out to 2,466,614,400 acres). Incidentally, if this were to happen, six and a half continents would be completely devoid of human life.
The conclusion to be drawn from this is that the world is not anywhere near over-populated, in terms of crowding. In fact, the world can support a much larger population than most people can fathom.