Risk, fear and nuclear power

California’s initiative process can be both a wonderfully democratic and perilously dumb way to make law. On no issue could that be more true than the proposed initiative to shut down nuclear power in the state. The initiative would shut down the Diablo Canyon and San Onofre nuclear plants until the federal government approves a permanent disposal site for nuclear waste. The issue is scientifically, environmentally and economically complex, and tangled with powerful emotions. Between the facts and those feelings, guess which will have more influence on the choice people make? Is that a wise way to make policy on something with such huge implications for human and environmental health?

Mountains of evidence from both scientific research and our everyday experiences make inescapably clear that risk perception is subjective. It is an instinctive process that relies on emotional and social cues and mental shortcuts for decision-making rather than an objective open-minded analysis of the facts. It is a process that sometimes leads us to worry more than the evidence warrants and sometimes less than the evidence warns — a phenomenon I call the perception gap.

The anti-nuclear initiative is a clarion example. Particularly among baby boomers, our nuclear fears are rooted in existential Cold War worries about nuclear weapons, which transitioned into fear of nuclear fallout from weapons testing , which transitioned into environmental concerns. Beyond that stigmatizing past, nuclear radiation bears many of the psychological characteristics that research has found make any risk scarier.

We’re more afraid of risks imposed on us than those we choose, which is why medical radiation is accepted but nuclear power radiation isn’t.

The more pain and suffering they cause, the more afraid we are of risks, and nuclear radiation is associated with cancer, even though studies of the survivors of Hiroshima and Nagasaki have firmly established that this form of radiation is a much weaker carcinogen than most people realize. The high doses and prolonged exposures from those explosions raised the cancer death toll among survivors who were within two miles of the explosions by only about half of 1%, according to the Radiation Effects Research Foundation, which coordinates the now 65-year-long epidemiological study of these survivors.

Nuclear radiation is undetectable to our senses, which leaves us without the ability to protect ourselves, and powerlessness and lack of control also make any risk scarier.

Many people don’t trust the Nuclear Regulatory Commission, and lack of trust in the organization that is supposed to protect you fuels fear too.

On top of those “risk perception factors,� nuclear energy is associated with industry and capitalism and institutions of economic and political power that some feel are responsible for an unfair society, one in which a few have most of the control and the rest are stuck lower on an economic and social class hierarchy too rigid to give everyone a fair shot. Many of the people who fight for that fairer world are more likely to be environmentalists because environmental damage is seen as caused by a few — the people in control of business and industry — while it unfairly jeopardizes all. Nuclear power triggers those feelings too.

That’s a deep pile of emotional baggage that will play a powerful role in the decision California voters may be asked to make if the initiative petition gains enough signatures by Monday to get on the November ballot. It will be hard for people with all those very real and valid feelings to accept that nuclear power has pros as well as cons.

Compared with its real but weak cancer risk, nuclear power emits no particulates, which are emitted from coal-fired power plants and which sicken and kill thousands of Americans each year, according to the National Academy of Sciences. Given the profound threat of climate change, it’s a huge plus that nuclear power generation emits practically no greenhouse gases.

And nuclear waste — which is carcinogenic at the same weak level as most nuclear radiation exposures — can be permanently stored. The Finns are close to opening a permanent repository. The Swedes aren’t far behind. The Obama administration’s commission on nuclear waste just recommended that the U.S. adopt parts of the Finnish-Swedish model, particularly the part giving local communities the final say over whether to host such a facility.

It is likely that if you are opposed to nuclear power, you had a negative reaction to that last paragraph, even viscerally negative. That’s my point: to note how easily our emotions can interfere with our ability to be analytical thinkers on complex issues.

This essay is not about nuclear power. It is a suggestion that we need to recognize the dangers of the perception gap, and how our emotional, instinctive, subjective risk perception can lead to judgments — in our personal daily lives and on initiative petitions and other forms of policymaking — that can do us more harm than good. Coming to grips with the flaws of risk perception is the first step toward avoiding its risks.

David Ropeik, an instructor at Harvard University and the author of “How Risky Is It, Really? Why Our Fears Don’t Always Match the Facts,� consults on communicating about risks.