In March, 1989, the Exxon Valdez ran aground in Prince William Sound and dumped nearly 11 million gallons of crude oil on Alaska’s shoreline.

More than 150 bald eagles and up to 4,500 sea otters died as a result.

I remember the story vividly, and I remember the gallant but pathetic-seeming efforts of volunteers to wipe syrupy crude off of oil-covered shore birds and otters.

At the time, experts predicted that the sea would wash away the oil, cleaning the beaches and rocks naturally, within about 4 years.

Last week, USA Today reported that 17 years later, it’s still there.

Experts are surprised and dismayed.

“We expected the natural decay rate was 25% a year. But very little of the oil actually disappeared,” says Jeffrey Short, a NOAA research chemist. “What’s left is going to be there a long time.”

Instead, the researchers estimate, the oil is “weathering” away at a rate of 3% to 4% a year. “It will be readily detectable for decades,” Short says.

Jennifer Culbertson, a marine ecologist at Boston University, is among the surprised. “The theory has been that on a rocky shore, it’s not going to stay for that long, that waves will wash it away,” she says.

Says Michael Baffrey of the Trustee Council: “We made a lot of assumptions about what would happen to the oil. A lot of those didn’t play out.”

To be sure, it’s a learning experience for scientists. It also underscores a lesson we should have learned along time ago: unintended consequences are usually the most significant consequences of all.

Jim: I hear stories like this and it illustrates something I really don’t get about the environmental movement. (Yes, I’ve made a similar version of this argument before.) Here we have a real environmental problem; something tangible, visible, and easy to understand. I don’t know if we have any single-hulled tankers still cruising around, but if there are, speeding up the transition to an all-double-hulled tanker fleet strikes me as a manageable worthwhile policy goal.

I think there are a lot of green conservatives out there, who want clean shores, who worry about preserving undeveloped open spaces. (Cam, that’s your cue to channel the hunters’ arguments for conservation.) I want public parks and plenty of shade in my cities, I want public transportation systems to cut down on drivers and subsequent car exhaust, I want my rain with as little acid as possible, and I want as little runoff going into the Chesapeake Bay as possible. In other words, I like environmental initiatives, but I want the benefits (and costs) to be tangible and visible, not theoretical.

But instead, the environmental movement is browbeating the country into signing a treaty that will have serious negative repercussions for our economy while doing jack squat about pollution from China and India. I’m supposed to worry about a ten degree change in three hundred years, and ice melting in places I’ll never see, and mathematical models that forecast conditions a century from now, when the weatherman can’t nail the forecast for later this week.

I think the small and the tangible (”act local”) part doesn’t appeal to environmentalists’ desire to play the role of Cassandra and/or savior of the world. There really is a religious component to the environmental movement, complete with a story of Garden of Eden, Man’s Fall (the industrial revolution), our impeding Judgment Day where we will be punished for our sins against Mother Earth, etc. Hopefully some aspiring political leader will figure out how to persuade Americans of the benefit of the small steps without trying to sell them on the Al-Gore-Is-The-Messiah-Of-Our-Age hype.