Well, I think if we begin to live right, our population will naturally be optimal and we wouldn't have to worry about it.
If we do as God intended and care for our land and water and air and everything in the universe, then we wouldn't have to fear too much as to how many people are living in it. If we live right, we'll have more to share with others...if we don't, we'll have nothing to share. I mean this world has enough good things without having people fighting over who should have more...I think what God intended was for us to have an earth that is pure, perfect and in harmony with Him...and I hope I can do my part to make that happen.