If there is anything resembling a silver lining to the economic turmoil that has ensnared the world, it is the prospect of falling energy prices. The price of crude oil has fallen by more than 50 percent since setting a record high this past summer. The Organization of Petroleum Exporting Countries (OPEC), the producers' cartel that tries to control oil prices, will hold an emergency meeting next week to try to set a floor for those plummeting prices.

The prospect of OPEC cutting production to hold prices at such high levels is outrageous, as British Prime Minister Gordon Brown suggested last week. Yet, the world needs stable energy prices; the impact of speculation and market manipulation must be minimized.

The changing structure of global demand has steadily increased the price of crude oil. Blistering economic growth in China and steady expansion in India, Asia and the Middle East propelled energy prices to a record $147.27 a barrel in July. Continuing high demand would keep prices high. A few bulls forecast prices would reach and stabilize at $200 a barrel; more sober analysts saw markets reaching equilibrium at $105 a barrel.

The financial crisis that has rattled global markets and the prospect of a recession in the United States have triggered an equally dizzying downward plunge in prices. U.S. demand has fallen 9 percent over the previous year; Japanese consumption dropped 12 percent in August. Global consumption is still expanding, but at a much slower rate than anticipated. Once forecast to grow more than 2 million barrels in 2008, now the world is consuming only 200,000 barrels a day more, less than 10 percent of those estimates.

Other factors contributed to the price drop. U.S. energy reserves have increased as production facilities came back on line after being shutdown by hurricanes during the summer. In addition, the credit crunch has forced speculators (often hedge funds) to unwind trades that used borrowed money — much of that betting on oil futures. This has intensified downward pressure on prices.

As a result, energy prices last week dropped under $70 a barrel to reach 14-month lows. Oil futures contracts anticipate prices of $50 a barrel in December. Prices have recovered slightly as investors anticipated a slight rebound — triggered by the extent of that fall and anticipation that cheaper energy might give the moribund economy a jolt.

OPEC, which controls about 40 percent of the world's oil, was certainly jolted. It has scheduled an emergency meeting later this month — rather than waiting until November — to try to combat the price slide. Some anticipate a cut in production of 1 million barrels to keep prices in the "ideal" range of $70 to $90 a barrel. That is the suggestion that outraged Mr. Brown — even though it is far from clear whether OPEC has the ability to enforce such a cut. (The organization has lacked discipline in recent years.) More worrisome still is the prospect of even greater cuts; some believe that a cut of 1 million barrels is not enough given the current economic woes.

Of course, some would argue that cutting the flow of money to Iran, Venezuela and Sudan is not a bad thing. Without their extraordinary oil revenues, those governments would be forced to trim their militant and aggressive policies. Russia too would be forced to readjust its thinking as a decline in oil prices would destabilize the platform upon which much of its recent assertiveness has been based.

There is a downside to falling energy prices, however. The energy market tends to be cyclical and future exploration and production depends a lot on energy prices today. As oil prices plummet, so too will investment in new fields and the maintenance of existing facilities. (Today's credit crunch will exacerbate those trends.) Cutbacks are invariably felt when economies recover. Suppliers are not ready when the demand curve either gets steeper or shifts to the right. This is what happened when prices collapsed in the 1980s and left energy producers unprepared for the Asian and Latin booms that followed. At that point, prices climbed as sharply as they fell, with deleterious effects on growth.

In short, what markets need is stability. That would allow governments and businesses to plan effectively for the future. It would eliminate — or at least minimize — the roller-coaster ride that has made some people lots of money but hurt many others. Ultimately, demand will recover and developing nations in particular will need energy at the lowest possible prices if they are to lift their struggling citizens out of poverty.

If that high-minded notion is too difficult to appreciate, then pure self-interest should suffice: Today's glut anticipates tomorrow's shortages. This should be a moment of opportunity, to facilitate readjustment, rather than a return to the rapacious consumption practices of the past.