Quest for energy is race against time
There are two reasons why society has to get out of oil, and at first sight, they seem contradictory. Firstly, oil is running out. Secondly, we cannot afford to burn it all.
Oil is running out because it is a finite resource. Optimists, like the US Department of Energy and the oil companies, estimate that around 2,600bn barrels are left in known deposits and predictable future discoveries. Pessimists, like the Association for the Study of Peak Oil and Gas, reckon on more like 1,000bn barrels.
In a society that has allowed its economies to become geared almost inextricably to growing supplies of cheap oil, the difference is seismic. If there are 2,600bn barrels left, the topping out point - or the so-called peak of depletion - lies far away in the 2030s.
(The "optimists" give us 25 years or so to redesign and rebuild the world to work without oil as our primary fuel. That does not seem like a lot of time to do all that needs to be done. Hello!? Is anyone paying any attention?)