Over-population is not just a problem of poor countries
Think of what it takes to sustain human civilisation at the standards of living we believe that everyone is entitled to. Have we stopped to think what it would mean for a billion Chinese people, say, to have access to a standard of living equivalent to that enjoyed by Western Europe and North America today?
If every Chinese household owned at least one car, think of what that will entail, how much roads, parking lots, garages, and the factories to make these cars will need to be built? Worse, how much fuel will all these cars burn?