We are about to enter a new era in which, each year, less net energy will be available to humankind, regardless of our efforts or choices. The only significant choice we will have will be how we adjust to this new regime. That choice - not whether, but how to reduce energy usage and make a transition to renewable alternatives - will have profound ethical and political ramifications.

The idea that we industrialized humans are immune to the natural laws that have restrained growth in other species-and humans in past social regimes-is to me so self-servingly blind as to be morally reprehensible.

As political theorist Michael Parenti points out, historians often overlook Fascism's economic agenda--the partnership between Big Capital and Big Government--in their analysis of its authoritarian social program. Indeed, according to Bertram Gross in his startlingly prescient Friendly Fascism (1980), it is possible to achieve fascist goals within an ostensibly democratic society.

The science is in: either we go cold turkey on our coal, oil, and gas addictions, or we risk raising the planet's temperature to a level incompatible with the continued existence of civilization.

Oil depletion and climate change will create an entirely new context in which political struggles will be played out. Within that context, it is not just freedom, democracy, and equality that are at stake, but the survival of billions of humans and of whole ecosystems.

If we do nothing, we still get to a post-carbon future, but it will be bleak. However, if we plan the transition, we can have a world that supports robust communities of healthy, creative people and ecosystems with millions of other species.

When a caterpillar eats a leaf, then a thrush eats the caterpillar, or when a hawk eats the thrush only 5 to 20% of usable energy is transferred from one level to the next. ... Thus herbivores will account for a much smaller fraction of the biomass [than plants] and the carnivores for a still smaller fraction.