The Art of ‘Manufacturing Uncertainty’

David Michaels, a professor at the George Washington University School of Public Health, served as assistant secretary of Energy between 1998 and 2001.

To many scientists and policymakers in Washington, the revelation this month that Philip Cooney, chief of staff for the White House Council on Environmental Quality, had rewritten a federal report to magnify the level of uncertainty on climate change came as no surprise. Uncertainty is easily manipulated, and Cooney -- a former lobbyist with the American Petroleum Institute, one of the nation’s leading manufacturers of scientific uncertainty -- was highly familiar with its uses.

As an epidemiologist with a special interest in occupational diseases, I share a fundamental problem with the scientists who are studying climate change. Our ability to conduct laboratory experiments is limited; we can’t go out and intentionally expose people to carcinogens any more than climatologists can measure future temperatures. Instead, we must harness “natural experiments,” collecting data through observation only. We then build models from this data, and use these models to make causal inferences and predictions, and, where possible, to recommend protective measures.

By definition, uncertainties abound in our work; there’s nothing to be done about that. Our public health and environmental protection programs will not be effective if absolute proof is required before we act. The best available evidence must be sufficient. Otherwise, we’ll sit on our hands and do nothing.


Of course, this is often exactly what industry wants. That’s why it has mastered the art of manufacturing uncertainty, of demanding often impossible proof over common-sense precaution in the realm of public health.

The tobacco industry led the way. For 50 years, cigarette manufacturers employed a stable of scientists willing to assert (sometimes under oath) that there was no conclusive evidence that cigarettes cause lung cancer, or that nicotine is addictive. An official at Brown & Williamson, a cigarette maker now owned by R.J. Reynolds, once noted in a memo: “Doubt is our product since it is the best means of competing with the ‘body of fact’ that exists in the mind of the general public.”

Toward that end, the tobacco manufacturers dissected every study, highlighted every question, magnified every flaw, cast every possible doubt every possible time. They also conjured their own studies with questionable data and foregone conclusions. It was all a charade, of course, because the real science was inexorable. But the uncertainty campaign was effective; it delayed public health protections, and compensation for tobacco’s victims, for decades.

The tobacco industry, left without a stitch of credibility or public esteem, has finally abandoned that strategy -- but it led the way for others. Every polluter and manufacturer of toxic chemicals understands that by fostering a debate on uncertainties in the underlying science and by harping on the need for more research -- always more research -- it can avoid debating the actual policy or regulation in question.

It is now unusual for the science behind a public health or environmental regulation not to be challenged. In recent years, corporations have mounted campaigns to question studies documenting the adverse health effects of exposure to, among others, beryllium, lead, mercury, vinyl chloride, chromium, benzene, benzidine and nickel.

Manufacturing uncertainty is a business in itself. You too can launch a pretty good campaign. All you need is the money with which to hire one of the main players in the “product-defense industry,” many of whose stalwarts first honed their craft defending cigarette smoke. These firms will hire the scientists, throw the mud, crank up the fog machine.


A classic case is beryllium, a lightweight metal useful in nuclear weapons. For many years it has been clear that workers exposed to beryllium levels below the federal Occupational Safety and Health Administration standard can develop chronic beryllium disease.

When OSHA tried to lower the standard, the industry hired Exponent, a leading product-defense firm to focus on all the things we don’t understand, calling for more research before OSHA could act. Meanwhile, workers are still exposed at the old, unsafe level, and are still getting sick.

Among themselves, these product-defense lobbyists and their clients make no secret of what they’re doing. Republican political consultant Frank Luntz wrote in a memo, later leaked to the press: “The scientific debate remains open.... Should the public come to believe that the scientific issues are settled, their views about global warming will change accordingly.”

Decades from now, this campaign to manufacture uncertainty will surely be viewed with the same dismay and outrage with which we now look back on the deceits perpetrated by the tobacco industry. But will it be too late?