A wise old owl lived in an oak, The more he saw the less he spoke, The less he spoke, the more he heard, Why aren’t we all like that old bird?

This is a long-lead-time business; the investment horizon is five, 10 or 20 years. There's no switch to pull.

So the major obstacle to the development of new supplies is not geology but what happens above ground: international affairs, politics, investment and technology.

You'll have innovators and entrepreneurs and people trying ideas that may seem sensible today or may seem way out. But out of that whole soup will emerge some new ways of doing things.

People always underestimate the impact of technology. To give you an example: In the 1970s the frontier for offshore development was 200 meters, today it is 4,000 meters.

The North Sea was supposed to run out in the 1980s. Then in the 1990s. And now production is still on-line.