The way the future looks could turn out drastically different depending on the population growth pattern of the world. Some people say that if the human race manages to keep growing the way it does now, our population should be nearing 20 billion in a hundred years. On the other hand, some say our population will level off around 2050. Each of these two possibilities could make the world develop in two different ways. Each one could be for the better or worse.

>20 billion person metropolis: We overcome our space and resource restriction and the human race prospers endlessly. Flying cars and Jetson type stuff.

>20 billion person dystopia: Everyone is dirt poor except for the top .0000000000001%, the world is one huge industry/junkyard, everyone is miserable and living in slums made out of corpses and kept together with expired cottage cheese. Picture Wall-E but with no ships coming to save the day and emaciated ghouls lying in the street crying out for sustenance. Not a pretty picture.

<9 billion person hippie paradise: Birth rate declines and new developments actually outpace population growth for once. There's is plenty of energy, food, and clean water to go around and everyone is happy with the global shift towards tofu and rampant birth control led by Dylan Sarkisian in the 2040s.

<9 billion people wasteland: The Earth finally runs out of resources for us, and a mass extinction takes place. Be it in the form of a zombie apocalypse, nuclear war, epidemic, or other catastrophic event, not many live, and those who do are forced to rebuilt the world by forming clans of in-bred rough-and-tough vigilantes who "ain't be need no FEMA hand-holdin'."