With everything else going wrong for the global economy, sharply lower energy prices have been one saving grace, unless one happens to live in Moscow, Riyadh or Caracas. Beware too much of a good thing though – any commodity price crash carries the seeds of its own reversal and it may come unexpectedly quickly this time.

Much has been written about delayed production. Low prices and tight credit are not only hurting economically marginal projects such as Canadian oil sands – even some conventional deepwater oilfields no longer meet oil companies’ investment criteria at prices below $50 a barrel. The International Energy Agency estimated that projects worth $100bn had been shelved in the past year.