The Longer We Wait, The Harder It Gets
Today, as the human population continues to expand, we have reached a situation in which our natural resources are beginning to diminish. Not just oil, but the supply of fresh water, forests, and prime farmland. While these problems may be temporarily addressed by exploiting the sea in ways not yet developed, that vast resource will also be exhausted, and in a surprisingly short time, if we don't learn to stop our growth. Technological advances may also help, but those who think that the oceanic well won't also run dry don't understand the law of exponential growth.
In another recent work, Collapse: How Societies Choose to Fail or Succeed2, Diamond talks about how and why certain highly developed cultures disappeared. He describes numerous cultures which, at the height of their apparent success, suddenly and/or completely disintegrated. A common theme is the fighting which breaks out when the effects of resource depletion become evident and everyone begins competing for the remaining vital supplies.
We humans are rapidly reaching the time when our resources will be so limited that managing to sustain ourselves will be problematic. Expansion to other worlds is not going to be an option then. Eking out survival on this one will dominate human activity. That Earth's resources are finite is an obvious fact. One need not be a scientist to argue this point. That humans are using those resources up is also obvious3. That we are in grave danger of trapping ourselves on this planet is, I hope, now apparent. Unless we do something about it soon, we'll be stuck on a toxic, dying planet fighting over the scraps of remaining resources with no hope of escape.
1 Diamond, Jared, Guns, Germs, and Steel: The Fates of Human Societies, WW Norton & Co. New York, NY, 1997
2 Diamond, Jared, Collapse: How Societies Choose to Fail or Succeed, Viking Penguin, New York, NY, 2005
3 There was a famous bet between the late Dr. Julian Simon and Dr. Paul Ehrlich in 1980 which the "Earth Destruction Lobby" (EDL) loves to cite as proof of exactly the opposite. If you've been impressed by the EDL's arguments on this matter, let me refer you to Dr. Ehrlich's comments at
find the web site and approach Ehrlich using this as motivation