Resources of the earth r not unlimited. China realised the problem of population growth long ago and its rate of population growth is much lower than ours. In a few years our population will b more than theirs, thou our surface area is much lower than theirs.
Population of developed world is now almost constant. It is only the poor countries of Asia and Afrika, where population growth is high. I do not know on what basis u r saying that i am in old stone age. Do u mean to say all developed countries r in stone age.
Population is definitely a big problem. Can u please tell what is the use of a large youthful population, if they cannot get clean air, clean water, good education, good house, good employment etc?