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.

All of the easy oil is gone and what's left is requiring more energy and money and this has an effect on everything. Our problem is that we've created an infrastructure that's so dependent on oil. As oil becomes more expensive we're going to be locked into the transportation modes that our economy depends on. So we really need to start building an alternative economy before we get caught in a trap of our own making.

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.

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.

What's new is high oil prices and the economy hates high oil prices.

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.