Thursday, October 11, 2012

Experts and Valdez

Below is an interesting excerpt from Garrett Hardin’s book Filters Against Folly. The important things to keep in mind are: 1) this book was published in 1985; and 2) though the cause of the infamous Exxon Valdez oil spill in 1989 was related to the pipeline below, it was is another unforeseen accident (a Black Swan?) which caused the damage, when an oil tanker crashed into a reef in Prince William Sound (the ship was coming from Valdez).


It is unfortunately true that experts are generally better at seeing their particular kinds of trees than the forest of all life. Thoughtful laymen can become very good at seeing the forest, particularly if they lose their timidity about challenging the experts. When I speak of laymen ("laypersons," if you prefer) I am talking about everyone, because the expert in one field is a layman in all others. In the universal role of laymen we all have to learn to filter the essential meaning out of the too verbose, too aggressively technical statements of the experts. Fortunately this is not as difficult a task as some experts would have us believe.

What follows is one man's attempt to show that there is more wisdom among the laity than is generally conceded, and that there are some rather simple methods of checking on the validity of the statements of experts.

The Expert as Enemy

I well remember the summer my wife and I went to Alaska to attend the annual meeting of the Pacific division of the American Association for the Advancement of Science. The year was 1969. Because bids were being submitted at this time for oil leases on Prudhoe Bay, many of the sessions of the AAAS were devoted to the possible economic, environmental, and social consequences of drilling oil at the rim of the Arctic Ocean and transporting it across the width of the state. A pipeline would have to be built, so the feasibility of this was also under discussion.

One of the delightful features of science meetings in this American outpost is the wide variety of people who attend. The usual assortment of professors and industry representatives is enriched with politicians, Indians, Aleuts, and Eskimos-groups seldom seen at science meetings in the "Lower 48." Discussion in Alaska frequently jumps out of the well-worn ruts.

One of the sessions was concerned with the expected effects of the proposed trans-Alaska pipeline. A lean, intense engineer made a sales pitch for the conglomerate scheduled to build the pipeline. His slide presentation was slick and convincing. The audience was bombarded with turgid tables and computer-generated graphs. The speaker gave the impression that every conceivable contingency had been dealt with.

Nevertheless, one layman was not convinced. This man, who had the rugged look of a modern sourdough, made his points very deliberately. "Let me see if I've got this straight. You say this 800-mile-long pipe, four feet in diameter and completely above ground for most of the distance, will be filled with oil which will be at 190 degrees when it enters tile pipe at tile northern end, right? And that the oil will cool continuously as it flows south, but it will still be 130 degrees, and fluid, when it reaches Valdez. Right?"

"Yes, that's right. Our computer model shows that the oil at Valdez will still be hot enough to flow during the coldest winter Alaska has ever had."

"What if there is some sort of traffic delay at Valdez and the oil has to stay in the pipe for a while, cooling all that time?"

"No problem. If there is a shortage of ships the oil can be held in the pipe for two weeks without solidifying. And remember, we have a tank farm at the south end to act as a buffer for the oil stocks."

“Yes. But suppose all the storage tanks are full, and then there is a tankers' strike that lasts three weeks. What happens then?”

The engineer's reply was cool and prompt: "That's an interesting question."

There is this to be said for the expert's response: it was honest. A politician in the same situation would no doubt have replied with some such words as these: "I'm so glad you asked that question. It gives me an opportunity to bring up another matter of the utmost importance to patriotic Americans, namely . . ." and his well-lubricated tongue would have generated a rhetorical smoke screen that would have eloquently submerged the original question. In blessed contrast, the engineer did not hide the fact that he had no solution to the difficulty.

Indeed, there is no general solution. In trying to picture the real situation, we must set aside the neat computer curves of the engineering analysis and picture a huge pipe that may, some frigid winter's day, be filled with 800 miles of something not too different from the tar of a blacktop road. No pumps in the world can move such a mass through so long a pipe. Even if we had the necessary pumps, the pipe could not withstand the pressure (particularly not the Alaska pipe, in the making of which-as we learned after it had been put in place-there had been cheating on the quality controls).

So what should a pipeline supervisor do when he gets the word, one unhappy winter's day, that the oil flow is going to be shut down at Valdez for an indeterminate period?

If the supervisor did nothing, and the shutdown lasted longer than two weeks, the pipe would become plugged with a viscous and immovable mass. Summer would not cure the ill: the Arctic summer is too short, and the angle of the sun too low to furnish the needed calories. There would be no practical way, ever, to heat the 800-mile pipe enough to make its contents fluid again. To avoid having to build a completely new pipeline, the supervisor would have to open valves somewhere and release the oil before it congealed.

But release it where? The pipe holds more than nine million barrels of oil. Cast you picture the devastation such a large quantity of oil would cause as it flowed out over the tundra? Alternatively, picture what nine million barrels of oil would do poured out over the ocean fishing grounds around Valdez.

Such are the pictures that were missing from the engineer's computer curves. The expert's response, "That's an interesting question," gave no hint of the reality.

Well, the pipeline was built. In more than a decade of operation no serious accident has occurred. But some day we may learn the answer to the citizen's question.