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.

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.

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.

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.

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.

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 we decline to talk about what is real simply because it's uncomfortable to do so, we seal our own fate.