Back in the 1970s, North Sea oil and gas were the great hope for the British economy. The UK had struggled to keep up with its European rivals in the three decades after the second world war, but the discoveries on the continental shelf were supposed to bring about a new Klondike gold rush. Britain would be self-sufficient in energy and the revenues from the North Sea would modernise the economy.
Getting on for four decades later, North Sea resources are running dry. Figures released by the Department for Energy and Climate Change on Thursday showed that oil production in 2011 was more than 17% lower than in the previous year. A total of 1.04m barrels a day was pumped, down from a peak of 2.7m in 1999, and the lowest since the 1970s. Gas imports were higher than production for the first time since 1967, the year the Beatles released Sgt Pepper.
George Osborne included a measure in his budget last week designed to end the uncertainty over the tax treatment of decommissioning rigs, hoping that the UK can extract every last drop of oil from the North Sea fields. This was welcomed by the industry, but doesn't change the grim truth: output is in terminal decline.
And what has Britain got to show for this bonanza? Not much. Norway has used its North Sea revenues to amass a sovereign wealth fund that will help the country adjust to an ageing population. Britain used its oil and gas receipts to pay for mass unemployment, tax cuts and current government spending.
Boasts that the black gold would retool British industry proved utterly hollow. If anything, oil added to the woes of manufacturing, since sterling's status as a petro-currency drove up the exchange rate and made exports uncompetitive. A fraction of the billions creamed off by the Treasury might have been used as the capital for a national investment bank, but neither Conservative nor Labour governments saw fit to use the receipts for this purpose.
Lower North Sea oil production is one reason for Britain's weak economic recovery and makes it harder for Osborne to balance the books. Even more worryingly, acute energy dependency looms. The coal mines have closed; the older nuclear power stations are on their last legs; the gush from the North Sea will soon be a mere dribble. An entire era can be summed up in three words: discovered, extracted, squandered.