Any system, biological, economic, or social, that gets so encrusted that it cannot self-evolve, a system that systematically scorns experimentation and wipes out the raw material of innovation, is doomed over the long term on this highly variable planet.

Models can easily become so complex that they are impenetrable, unexaminable, and virtually unalterable.

Biodiversity can't be maintained by protecting a few species in a zoo, or by preserving greenbelts or national parks. To function properly, nature needs more room than that. It can maintain itself, however, without human expense, without zookeepers, park rangers, foresters or gene banks. All it needs is to be left alone.

The scarcest resource is not oil, metals, clean air, capital, labour, or technology. It is our willingness to listen to each other and learn from each other and to seek the truth rather than seek to be right

Everyone except the far right wing of the Republican Party realizes that oil, gas and coal burning are the main activities that have sent the climate into bigger floods, droughts, hurricanes, and El Ninos

The world is a complex, interconnected, finite, ecological - social - psychological - economic system. We treat it as if it were not, as if it were divisible, separable, simple, and infinite. Our persistent, intractable global problems arise directly from this mismatch.

We don't think a sustainable society need be stagnant, boring, uniform, or rigid. It need not be, and probably could not be, centrally controlled or authoritarian. It could be a world that has the time, the resources, and the will to correct its mistakes, to innovate, to preserve the fertility of its planetary ecosystems. It could focus on mindfully increasing quality of life rather than on mindlessly expanding material consumption and the physical capital stock.