Every year since 1993, U.S. offshore oil drilling has spilled an average of 47,800 barrels of oil into the water. At that rate, it takes about 10 years to spill as much as was spilled during the Exxon Valdez disaster. Offshore oil drilling, seen that way, is just a slow-moving spill.

Wrong. At that rate, it would take 230 years to equal the Exxon Valdez spillage.

Update: As a commenter pointed out, our math is wrong as well. We confused gallons with barrels. It will actually take just more than six years. We regret the error.

House Majority Leader Steny Hoyer (D-Md.) told reporters Tuesday that Democrats have no plans to reinstate the drilling ban, which Congress let expire at the end of September amid a charged partisan debate over sky-high gas prices. Instead, Hoyer said party leaders will probably search for ways “to delineate” the vast swaths of ocean now available for drilling.

“At this point in time, no one is suggesting that we return to the same position we were in [before the ban expired],” Hoyer said. “We’re going to be looking at parameters, not necessarily reinstatement of the [moratorium].”

President-elect Barack Obama could also reinstate a (separate-but-equal) White House ban, which President George W. Bush repealed over the summer. Obama, however, has welcomed expanded offshore drilling as part of a comprehensive energy reform package. He’s given no indication that he would reinstall the presidential ban next year.

Meanwhile, fuel prices have nosedived since the drilling debate peaked in August, leaving oil companies with much less incentive to expand their expensive deep-sea drilling operations. If prices stay low, environmentalists can probably sleep well, even if the ban isn’t reinsated.

That move, the companies postulate, “may prove to be a significant measure in addressing our long-term fiscal health.”

Really?

Forget, for a moment, that oil is a finite resource that’s difficult to locate and filthy to extract. Forget that Hurricanes Katrina and Rita spilled 685,000 gallons into the Gulf in 2006, and Hurricane Ike spilled at least another 500,000 gallons more this year. Forget also that the United States sits on just 3 percent of the planet’s known reserves.

The real issue is economic, and the Energy Dept. has determined that opening the outer continental shelf to new exploration won’t have a tangible impact on production or prices before 2030.

That’s 22 years away.

Imagine, while we continue to peck away at fossil fuels, what Europe and Japan will be doing over that span to develop renewable energies, cleaner fuels and the engines that will run off them. Imagine the myriad industries that will arise from that development, the remarkable products devised and the countless jobs created.

In 2030, just as our expanded oil drilling is projected to benefit consumers, consumers may very well have graduated to another generation of vehicles fueled by something much cleaner than petrol. Honda, after all, is already selling zero-emission hydrogen-cell cars in California.

As New York Times columnist Tom Friedman has pointed out, clean energy remains a fledgling enterprise, and “the country that most owns the clean power industry is going to most own the next great technology breakthrough.” The focus on more drilling, he adds, “is a strategy for making America a second-rate power and economy.”

That’s a prediction much different from the one (unbiased, we’re sure) put forth by the energy industry. But if he’s right, new drilling — while it might prove a wonderful short-term boon to the oil industry — will have come a far cry from healing our long-term economic troubles.