Scientific American - 09.2019

78 Scientific American, September 2019 Graphic by Jen Christiansen

SOURCE:

RISK: A VERY SHORT INTRODUCTION,

BY BARUCH FISCHHOFF AND JOHN K ADVANY. OXFORD UNIVERSITY PRESS, 2011;

REDRAFTED FROM “HOW SAFE IS SAFE ENOUGH? A PSYCHOMETRIC STUDY OF ATTITUDES TOWARDS TECHNOLOGICAL RISKS AND BENEFITS,” BY BARUCH FISCHHOFF ET AL., IN

POLICY SCIENCES,

VOL. 9, NO. 2; APRIL 1978

mate research. Sponsored by the Department of En-

ergy, the project had five working groups. One dealt

with the oceans and polar regions, a second with the

managed biosphere, a third with the less managed

biosphere, and a fourth with economics and geo-

politics. The fifth group, which I joined, dealt with so-

cial and institutional responses to the threat.

Even then, 40 years ago, the evidence was strong

enough to reveal the enormous gamble being taken

with our planet. Our overall report, summarizing all

five groups, concluded that “the probable outcome is

beyond human experience.”

THINKING OF THE UNTHINKABLE

HOW, THEN, CAN RESEARCHERS in this area fulfill their duty

to inform people about accurate ways to think about

events and choices that are beyond their experience?

Scientists can, in fact, accomplish this if they follow

two basic lessons from studies of de cision-making.

LESSON 1: The facts of climate science will not speak

for themselves. The science needs to be translated

into terms that are relevant to people’s decisions

about their lives, their communities and their society.

While most scientists are experienced communicators

in a classroom, out in the world they may not get feed-

back on how clear or relevant their messages are.

Addressing this feedback problem is straight for-

ward: test messages before sending them. One can

learn a lot simply by asking people to read and para-

phrase a message. When communication researchers

have asked for such rephrasing about weather fore-

casts, for example, they have found that some are con-

fused by the statement that there is a “70  percent

chance of rain.” The problem is with the words, not

the number. Does the forecast mean it will rain 70 per-

cent of the time? Over 70 percent of the area? Or there

is a 70  percent chance of at least 0.01 inch of rain at

the weather station? The last interpretation is the cor-

rect answer.

Many studies have found that numbers, such as

70 percent, generally communicate much better than

“verbal quantifiers,” such as “likely,” “some” or “of-

ten.” One classic case from the 1950s involves a U.S.

National Intelligence Estimate that said that “an at-

tack on Yugoslavia in 1951 should be considered a se-

rious possibility.” When asked what probability they

had in mind, the analysts who signed the document

gave a wide range of numbers, from 20 to 80 percent.

(The Soviets did not invade.)

Sometimes people want to know more than the

probability of rain or war when they make decisions.

They want to understand the processes that lead to

those probabilities: how things work. Studies have

found that some critical aspects of climate change re-

search are not intuitive for many people, such as how

scientists can bicker yet still agree about the threat of

climate change or how carbon dioxide is diff erent

from other pollutants. (It stays in the at mosphere lon-

ger.) People may reject the research re sults unless sci-

entists tell them more about how they were derived.

LESSON 2: People who agree on the facts can still

disagree on what to do about them. A solution that

seems sound to some can seem too costly or unfair

to others.

For example, people who like plans for carbon cap-

ture and sequestration, because it keeps carbon diox -

ide out of the air, might oppose using it on coal-fired

power plants. They fear an indirect consequence:

cleaner coal may make mountaintop-removal mining

more acceptable. Those who know what cap-and-

trade schemes are meant to do—create incentives for

reducing emissions—might still believe that they will

benefit banks more than the environment.

These examples show why two-way communication

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Nuclear power

Food coloring

Food preservatives

Spray cans

X-rays

Antibiotics

Contraceptives

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Railroads

Electric

power

Home appliances

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