Using science to perfect the world a tough proposition

February 22, 2003

Often the most vexing political issues have at their core a scientific question. What to do about global warming, genetically modified foods or human cloning depends, in part, on what scientists believe can be done about such things.

But the way science and politics interact is more complicated than most people think, says historian of science Naomi Oreskes, a geologist who is a member of the history department at the University of California at San Diego. Speaking on a panel at the recent convention of the American Association for the Advancement of Science in Denver, she offered three cautionary tales. She titled her talk, "Proof is overrated (or, why facts are not enough)."

First, here's her abbreviated description of the "perfect world."

Scientists collect facts.

Politicians adopt policies based on the facts.

Legislatures pass laws to implement the policies.

Government agencies enforce the laws.

And -- here's where the perfection comes in -- because the laws are based on science, they work, and all our problems are solved.

But the world does not work this way. At least it doesn't work this way always or entirely, and specifically, scientific proof "does not play the role -- either in science or in policy -- that most of us think it does (or should)," she said.

First example, successful policy without scientific proof: Rachel Carson and Silent Spring, published in 1962.

Silent Spring "was to environmentalism what Uncle Tom's Cabin was to abolitionism," Oreskes says, enormously successful and influential. In response, President Kennedy ordered a review of government policies on pesticides that eventually led to the establishment of the Environmental Protection Agency (1970) and the ban on DDT (1972).

Oreskes believes that was a positive outcome. Given the millions of preventable deaths from malaria that have resulted from the ban, I am not so certain. But that debate is not relevant to her main point, which is that at the time Carson's work began to affect policy, she had not proved her case to the scientific community. For example, scientists in the U.S. Department of Agriculture opposed Carson's conclusions, while those in the Department of the Interior supported them.

Critics said her evidence was anecdotal, her conclusions were exaggerated and her book appealed to the emotions. Oreskes noted, in passing, that calling a book "emotional," even though it was, was indirectly a reference to the fact that the author was a woman and therefore not to be taken as seriously as a man would be. There's something to that.

Her second example, successful science without proof: Alfred Wegener and the theory of plate tectonics.

Wegener proposed his theory of continental drift in 1912. There was substantial evidence for it - the shape of the continents (Africa and South America), similarities between kinds of animals now living in areas separated by an ocean, and more. The evidence was widely accepted but the theory was rejected, Oreskes said. If the continents were really drifting, the only conclusive proof would be to measure the drift.

But that couldn't be done directly until the satellite era, in the mid-1980s. Nonetheless, plate tectonics had become the established theory nearly 20 years earlier, when it was still unproven, at least by the standards of the debate during Wegener's lifetime.

Her third example, scientists who offered proof (or something close to it) that no one wanted: an experiment to determine whether the earth's climate is warming and, if so, by how much.

Oceanographers proposed to measure the earth's temperature by measuring the temperature of the earth's oceans, a project called Acoustic Thermometry of Ocean Climate (ATOC).

You can do that because the speed of sound in water depends on the water temperature. Sound travels faster in warm water, so the time it takes sound to travel over long distances measures the average temperature of the water it passes through, according to the ATOC home page.

What you do: Measure speed over a long distance, for example between California and Hawaii. Do it in several of the world's oceans. Repeat for a decade or so and you have an answer to one of the most contested political questions on the planet.

The science was well understood and the technology straightforward. There was even funding available, Oreskes said. A pilot program of transmissions starting in 1995 demonstrated the project was feasible.

So it's 2003; is the answer to this highly important question forthcoming? No, because advocates for marine mammals raised such a stink about it that the project was shut down. They worried that the sound transmission would interfere with the singing of humpback whales.

Probably needlessly -- the pilot program researched that, too, and had not found any significant biological effects -- but the research did not continue long enough to find out. ATOC's sad little Web site, which still exists, indicates the last transmission from Hawaii was in October 1999.

On the contested ground where science and politics meet, the world is not at all perfect.