Every now and then it is necessary to turn to history for a reality check. This is because whilst history is not a perfect guide for the future, it is arguably the best we have. There is now a broad consensus that the sine qua non for sustainable economic development is energy efficiency, clean technology, renewable sources of energy, reforestation and ‘smart’ infrastructure. The world must shift from fossil fuels (coal, oil, gas) to ‘greener’ energy.

History, however, forewarns against complacency. It throws up example after example of the long lead times and the huge investments required to transit from one energy system to another. The leaders that will congregate in Copenhagen in December to deliberate on what the world must do to mitigate and adapt to the consequences of global warming should keep these examples somewhere in the back of their minds. Because it will help them distinguish between the high notes of the ‘ideal’ from the dull tones of the ‘feasible’.

The 19th century is talked of as the era of coal; the 20th century as that of oil. Similarly, people are hopeful that the 21st century will be the age of renewables. The sweep of these comments misses one essential point. The growth of oil in the 20th century did not lead to the end of coal. Equally, the onset of solar, wind and bio energy will not result in the displacement of fossil fuels.The reasons are not simply because of cost and convenience, although these are compelling. It is also because of embedded energy infrastructures and the gestation period between the development of a new technology and its commercial deployment.

... contd.