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.

Today, it is especially difficult for most people to understand our perilous global energy situation precisely because it has never been more important to do so.

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.

The real problem is that we use too much oil. It's that simple and that difficult. If we truly want to reduce our vulnerability to high prices, the best way to do so is to reduce consumption.

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.

Economic growth as we have known it is over and done with.

Surveying the available alternative energy sources for criteria such as energy density, environmental impacts, reliance on depleting raw materials, intermittency versus constancy of supply, and the percentage of energy returned on the energy invested in energy production, none currently appears capable of perpetuating this kind of society.