"Our enormously productive economy... demands that we make consumption our way of life, that we convert the buying and use of goods into rituals, that we seek our spiritual satisfaction, our ego satisfaction in consumption. We need things consumed, burned up, replaced and discarded at an ever-accelerating rate."
I'm not knocking idealism, but this is the model that everyone is adopting/has adopted. How are you going to change a system and a culture this large that has been exported around the world? People can go back to locally sustained economies, but is that feasible for supporting a world of 7 billion people? If this is really the problem, then I think we are doomed. Doomed!
Also, there is no 100% efficient system as far as I know. Every system loses energy. You can't have a complete circle unless there is no energy lost, right? You still need a constant input into the loop to keep it going.
Though energy is never lost. So at a cosmic level, it is one big circle. And maybe this is the way it ought to be for us. To over-extend ourselves, then die off in a mass extinction like the Permian. Then we will become the fossil fuels of some future sentient race that populates the planet. A race that evolves after an ice age after all of the carbon is once more returned to the earth and the ocean floor.