Six months ago when King Abdullah of Saudi Arabia convened an energy summit in Jeddah the mood between producers and consumers was of barely concealed hostility. Oil prices were $130 a barrel and rising and the Organisation of the Petroleum Exporting Countries and other producers seemed indifferent to the consequences. Few would have predicted then that before the year was over energy ministers would be gathering for a second summit in London with oil prices slipping below $40.

The mood at next week's meeting will be very different. There is growing awareness among both producers and consumers that the volatility that took prices from $60 a year ago to more than $140 in July, before the current slide began, has damaged everyone involved.

The sharp rise accompanied by wild predictions that they would continue to rise to $200 (Goldman Sachs) or even $250 (Gazprom) helped destabilise econ?omic activity through the spring and early summer. Price increases led to a sudden transfer of wealth from economies large and small while the risk of inflation constrained governments anxious to stimulate faltering growth. Inaction contributed to the loss of confidence in important asset prices.