Here is the seventh and final step we should take to reach a sustainable society (click here for step one, step two, step three, step four, step five, and step six). Seven: Determine the institutions and arrangements best suited to govern a planetary society with a maximum of freedom within the constraints of sustainability. This is closely related to step six. In the 200,000 year history of Homo sapiens, states are a recent invention, existing for only a tiny fraction of our existence. In their modern form as nation states, they are only a little more than 200 years old. We need to look closely at possible alternatives that could combine greater awareness of the problems of living at a global scale while regaining family-style psychological comfort. More cooperation at a global level is clearly necessary for civilization's long-term survival. All seven of the steps could be written of as an exercise in Pollyannaism. "Totally impractical," people will say, "not gonna happen." Well, I tend to agree. But there is nothing more impractical than letting our global civilization go down the drain, with billions of people dying. Pundits seem to think we have choices, but they are wrong. If we don't change our ways, they'll be changed for us. What do you think? Leave us a comment. ———- Paul R. Ehrlich is Bing Professor of Population Studies and Professor of Biological Sciences at Stanford University. He is the author of hundreds of scientific papers, and numerous books including The Population Bomb and Betrayal of Science and Reason (Island Press, 1997). His latest book is The Dominant Animal: Human Evolution and the Environment, which he co-authored with his wife Anne.