Boston — ''It's a race between crisis and adjustment.''
That's how Harvard energy expert Daniel Yergin sees the future.
''In the short term, there will be continuing pressure from oil prices - although we have had two years' grace, mostly the result of the deep recession and of conservation.
''And yet in the long term, I'm cautiously optimistic because there's such tremendous flexibility and innovation,'' he says, speaking of the way the world's economies have adjusted to the end of the era of cheap oil.
This by no means suggests Dr. Yergin thinks the energy crisis is over. On the contrary, he has just issued a warning that a third ''oil shock'' could hit during the 1980s, with effects far more severe than those of its predecessors in 1973-74 and 1979-80.
''Glut can turn to shortfall, he says, ''on little more than an assassin's bullet.''
Dr. Yergin is the editor, with Martin Hillenbrand, of ''Global Insecurity: A Strategy for Energy and Economic Renewal.'' The book, just released this week, argues that the trigger for a third oil shock would most likely be an ''accident'' - political or otherwise - in the Middle East, coming at a time of generally rising demand for oil and increased economic activity.
In a telephone interview, Dr. Yergin cites three reasons why a third energy shock would hurt worse than its predecessors:
* Energy costs are a much larger share of gross national product now than in 1973.
* The economy as a whole is less resilient.
* The volatile Gulf region would be even more important as a source of oil than today, since production is expected to decline in the United States, Nigeria, Libya, Indonesia, and Britain.
A third oil shock, he says, could prove ''a test of the American system on a scale matched in this century only by that of the Great Depression.''
On the other hand, ''It need not be, if we are lucky, or if we plan wisely, which we don't seem particularly to be doing,'' he adds.
The two oil shocks of the 1970s had a more fundamental effect than is generally acknowledged, especially in the US - they cost the ''big seven'' industrial nations $1.2 trillion in lost economic output. And they continue to cost, notably in the form of high unemployment.
''The energy question is not a question of whether gas prices are 70 cents a gallon or $1.40 or whatever, but of economic growth and hence of democracy,'' says Yergin.
He says the lack of consensus on the energy issue in the US - indeed, the lack of consensus that there is an energy issue - hinders intelligent policymaking, which must take a long-term view.
''We seem to have a new energy policy every two years,'' he laments.