The world population was a billion in 1800. As for places to go to, most of North America, Africa, South American and Australia are sparsely populated. Even half of Asia is sparsely populated. Overcrowding takes place in cities, which occupy a tiny percentage of the world's land mass.

That said, more birth control across the developing world should be encouraged. Otherwise you will have millions of Africans pouring into Europe. It isn't "someone else's problem".