Obama's Scientists...

Sound more political than Bush's...

Why, since President Obama promised to “restore science to its rightful place” in Washington, do some things feel not quite right?

First there was Steven Chu, the physicist and new energy secretary, warning The Los Angeles Times that climate change could make water so scarce by century’s end that “there’s no more agriculture in California” and no way to keep the state’s cities going, either.

Then there was the hearing in the Senate to confirm another physicist, John Holdren, to be the president’s science adviser. Dr. Holdren was asked about some of his gloomy neo-Malthusian warnings in the past, like his calculation in the 1980s that famines due to climate change could leave a billion people dead by 2020. Did he still believe that?

“I think it is unlikely to happen,” Dr. Holdren told the senators, but he insisted that it was still “a possibility” that “we should work energetically to avoid.”

Well, I suppose it never hurts to go on the record in opposition to a billion imaginary deaths. But I have a more immediate concern: Will Mr. Obama’s scientific counselors give him realistic plans for dealing with global warming and other threats? To borrow a term from Roger Pielke Jr.: Can these scientists be honest brokers?

Dr. Pielke, a professor in the environmental studies program at the University of Colorado, is the author of “The Honest Broker,” a book arguing that most scientists are fundamentally mistaken about their role in political debates. As a result, he says, they’re jeopardizing their credibility while impeding solutions to problems like global warming.

Most researchers, Dr. Pielke writes, like to think of themselves in one of two roles: as a pure researcher who remains aloof from messy politics, or an impartial arbiter offering expert answers to politicians’ questions. Either way, they believe their research can point the way to correct public policies, and sometimes it does — when the science is clear and people’s values aren’t in conflict.

But climate change, like most political issues, isn’t so simple. While most scientists agree that anthropogenic global warming is a threat, they’re not certain about its scale or its timing or its precise consequences (like the condition of California’s water supply in 2090). And while most members of the public want to avoid future harm from climate change, they have conflicting values about which sacrifices are worthwhile today.

A scientist can enter the fray by becoming an advocate for certain policies, like limits on carbon emissions or subsidies for wind power. That’s a perfectly legitimate role for scientists, as long as they acknowledge that they’re promoting their own agendas.

But too often, Dr. Pielke says, they pose as impartial experts pointing politicians to the only option that makes scientific sense. To bolster their case, they’re prone to exaggerate their expertise (like enumerating the catastrophes that would occur if their policies aren’t adopted), while denigrating their political opponents as “unqualified” or “unscientific.”

“Some scientists want to influence policy in a certain direction and still be able to claim to be above politics,” Dr. Pielke says. “So they engage in what I call ‘stealth issue advocacy’ by smuggling political arguments into putative scientific ones.”