Once And For All: The Precautionary Principle is Not Unscientific

Some conservatives are immensely more fun to debate than others.

In the past month, a debate over left-right science abuse with Kenneth Green of the American Enterprise Institute led to him hurling charges of “socialism.” Not kidding.

Unfortunately, “Carol Browner is a socialist” isn’t an argument. It’s a heuristic device. It’s the kind of thing you say if you want to get emotive Tea Party reasoners whipped up.

Ron Bailey of the Reason magazine is, in contrast, full of…reason. He weighed in last week on this topic, went through the issues, and came down slightly differently than I did on some of them, but actually agreed that the GOP is doing much worse now with respect to science.

In the process, Ron also made me pretty concerned about Democrats and GM salmon. If there’s no serious risk here—and Ron and also this piece at Science Progress make a strong case that way—then we shouldn’t be scare-mongering about this technology.

I want to say a few things about Ron’s commentary, though, because I think it still has some flaws. In particular, I want to take on his criticism of the so-called “precautionary principle,” which he charges is “unscientific in the sense that it demands the impossible: Researchers can never show that any technological or scientific activity will never produce significant harm.”

Even this would not be “unscientific” by my definition. It would still be a moral or policy position, albeit an indefensible one.

But of course, this is not what precaution, in a reasonable sense, actually means. Ron Bailey’s own source on this matter, Obama administration OMB official Cass Sunstein, agrees with me:

I have suggested that the weak versions of the precautionary principle are unobjectionable and important. Every day, people take steps (and incur costs) to avoid hazards that are far from certain. We do not walk in moderately dangerous areas at night; we exercise; we buy smoke detectors; we buckle our seatbelts; we might even avoid fatty foods. Sensible governments are willing to consider regulation of risks that, in individual cases or even in the aggregate, have a well under 100% chance of coming to fruition. The weak versions of the precautionary principle state a truism—uncontroversial and necessary only to combat public confusion or the self-interested claims of private groups demanding unambiguous evidence of harm, which no rational society requires. This function should not be trivialized. Nearly a  fifth of Americans, for example, recently agreed that “until we are sure that global warming is really a problem, we should not take any steps that would have economic costs.” Sometimes people do seem to seek certainty before showing a willingness to  expend costs, and well-organized private groups like to exploit this fact. Insofar as the precautionary principle counteracts the tendency to demand certainty, it should be approved.

This “weak” version of the precautionary principle is certainly the one I would espouse. Obviously, you can’t demand that any person introducing any new product, service, or activity must first prove conclusively that no harm will ever come from it before allowing anything to go forward. That would throw total sand in the gears of everything, and is certainly not how precaution is practiced in the United States (where the government regulatory structure nevertheless remains, to my mind, broadly precautionary).

If you were to apply precaution in this mindless way, you could make a case that we should still be worried about vaccines and autism. Despite the many epidemiological studies and scientific consensus reports that have shown there’s no reason to worry about this risk, we're definitely not, like, certain ​that vaccines are safe.

But if you apply precaution in my and Sunstein’s weak version, you don't worry about vaccines but you do end up very very concerned about global warming. Because we know it’s real, and while there’s much uncertainty about the range and speed of the impacts, it is precisely that uncertainty that's so disturbing–because the magnitude of the consequences could staggering.

So you don’t apply precaution when there isn't any evidence of anything to worry about. Rather, when there is good evidence that you have something to worry about but you don’t know how bad it is going to be–and it could be quite bad–precaution becomes a sensible policy indeed.

How do you make the distinction? You weigh the best science, plain and simple. And if it doesn't suggest a risk–as in the vaccine case–then move on. There are many, many other things worth worrying about.

Have environmentalists ever gone a bit overboard with the precautionary principle? Sure they have. I’ve certainly heard it invoked as a slogan, rather than a sensible policy to address situations involving real but unknown risk. And I agree that it’s a misuse of the principle to wield it against technologies, like GM crops, where scientific consensus reports show the risk to humans isn’t a big deal.

So all that is conceded. But let’s remember too: This is really a nuance in our broad debate over left-right science abuse.

What’s actually happening out there in the world, on the right wing, is far more extreme than gaming the precautionary principle. We're talking about utter and often willful denial of scientific reality, including by leading policymakers and presidential candidates.

These people worry me, and I have evidence to support my concern. So I think we should employ the precautionary principle against further political triumphs by anti-science ideologues.

The weak version, of course–strongly applied.


I saw that the article had 4 comments and by the time I logged in their were only 2. Comments are being deleted again almost as I’m reading them. What the heck, were they that offensive??

Hank, the comment policy is clear. We will delete comments that don't adhere to it.  Once again, with the key parts bolded for incredible clarity: http://www.desmogblog.com/comment-policy

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