Over the past 150 years, human society's damage to its local and global environment has increased dramatically. Nowadays, those environmental harms are more and more coming back to harm humans as well as other species. If we keep on this way, human society will suffer increasing disasters and not be sustainable into the future. This course explores why this situation has come about and what we can do about it. Three factors: growth of population, affluence and technology, causing more resource withdrawals from and polluting inputs into the environment, are the immediate causes of its decline. The social sciences explain why we have often ignored the issue, even if we have clear natural science knowledge of the problem, and as a result, failed to head off predictable environmental disasters. The current global scale of environmental change presents even bigger risks, but also great opportunities to learn how to cooperate to better manage our "Spaceship Earth."