It maybe comforting to say: "Well, look, it's only 30 per cent of primary energy, whereas 25 years ago it was 50 per cent or something. The fact is that we use more of it today than we did 20 years ago. And assuming that the supply side Peak Oil theory isn't actually correct, we'll continue to use more and more and more, until we hit some other limit in terms of what we can actually produce. So we're... In that sense, we are very dependent on oil. And oil is an important aspect of primary energy, and that it is so useful. It's used primarily as a transportation fuel. Maybe 15 per cent of it goes into products. Plastics and other products. So most of it is actually used as a fuel. And as a fuel it is enormously convenient. It's very energy dense in terms of energy per volume and energy per unit weight. And so it's easy. You carry a little bit of it around, you carry a little bit of it with you, in you car or in your airplane, and you can go great distances.
There are lots of things you can do in the car instead, we could burn natural gas, we could load up the car with batteries and battery technology gets better. For airplanes there aren't too many alternatives right now. And so we have to be thinking hard and planning for what actually does happen, not 10 or 20 years from now, but 30 or 50 years from now, to replace this incredibly useful and convenient source of energy as a fuel.
So planning for the end of oil means innovating... It's not planning in a formal sense, but it means innovating and developing new ideas and new technologies, which 30 to 50 years from now could be the basis for radically different primary energy supply.