Spaceships carry a limited supply of food and water with them, and the crew must be disciplined about those limited reserves. It would be fatal to run short, but it would also be fatal to contaminate even a small portion of food and water. Because we haven't seen Earth in the same way, we've lost all discipline. This concept of Spaceship Earth goes back to visionary thinker Buckminster Fuller, and now is the time to pay heed to it. After centuries of human influence, there is contamination everywhere.
The toxic oil spill in the Gulf of Mexico is heartbreaking and so massive that it cannot be overlooked. But 30 years ago, pioneering ocean explorer Jacques Cousteau reported that every square mile of the world's oceans is covered with a thin film of oil. It's barely visible, if at all, but it's there. Because there are seemingly endless stretches of ocean—just as there seemed to be endless stretches of ice at the poles—human beings could afford to pretend that we aren't living on a spaceship.
That time is at an end. Technology will eventually bring an end to fossil fuels. Water diversion can bring drinking water to the overcrowded cities where clean, potable water is quickly running out—several in India, including Mumbai, are reaching the critical point. Genetic therapies may one day bring down cancer rates by more than a trifling amount. In other words, if you are an optimist, the hazards of climate change and overpopulation are waiting for solutions that will one day emerge, hopefully sooner than later.What you can do to make a difference