The consensus that the collapse in oil prices is a net positive for the world economy overlooks the long-term effects of cheap fossil fuels.

Lee Raymond, the famously pugnacious oilman who led ExxonMobil between 1999 and 2005, liked to tell Wall Street analysts that covering the company would be boring.

Judging by newspaper headlines, a silver bullet against polluting fossil fuels is at hand.

India has become an agricultural food exporter, but government policy may soon sabotage this.