Science in Mind

Assessing risks, and responsibilities, of predictions

An earthquake centered in L’Aquila in central Italy killed more than 200 people in April, 2009.
archivio Lotus international
An earthquake centered in L’Aquila in central Italy killed more than 200 people in April, 2009.

Last fall, a former government official and six Italian scientists were found guilty of manslaughter in a trial centered on information they provided about risk just before the 2009 L’Aquila earthquake. The ruling sent waves of alarm through the scientific community, sparking concerns that researchers around the world could be held accountable for giving governments advice about natural disasters, which are inherently unpredictable.

Last week at the MIT Museum, a panel including an Italian architect, a seismologist from the Massachusetts Institute of Technology, and a specialist in dispute resolution from Harvard Law School discussed what happened in Italy and its ripple effects.

Robert van der Hilst, head of the department of Earth, Atmospheric, and Planetary Sciences at MIT and a member of the panel, said the case attracted international attention because it could have a chilling effect on scientists’ communications with the public and government officials.


“It’s very much in good faith. . . . You try to do your best, working with the data you have, looking at all the uncertainties,” said van der Hilst. “It may discourage people from giving proper advice to people when asked. Expanding that, extrapolating further, it may even discourage people to go into those areas, and in the long term, it will have a really negative effect.”

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There is currently no way to predict earthquakes, but seismologists are often asked the question.

In Italy, a scientific panel was asked what to make of tremors that occurred in the days before the devastating L’Aquila temblor. The scientists did the right thing, van der Hilst says: They assessed the likelihood of a large, devastating earthquake, and found it extremely low. However, the message given to the public was deemed too reassuring by the Italian judge.

“The concern was not so much they did not predict the earthquake but that they were rather cavalier in what they said,” van der Hilst said.

It’s not easy to communicate uncertain risks to the public. For example, no scientist can guarantee there is no possibility a massive earthquake will hit Boston this week. So should government officials send out a warning about a tiny, but non-zero risk of a catastrophic earthquake? It would not make sense for people to take protective actions and leave the area. And if every high-risk but extremely-low-frequency event were to be treated seriously, the credibility of governments and scientists would rapidly wither.


Van der Hilst said that scientists and professional societies are talking about what can be done to help scientists and policy makers communicate uncertain risks to the public accurately — without falsely reassuring them and without inciting a panic. The obvious strategy would be to take long-term preventive steps: create buildings that will not fall down and kill people, for example.

But the issue at the heart of the court battle over earthquake in Italy reverberates beyond the challenge of predicting earthquakes. Other complicated systems that evolve over time, such as the climate and the economy, present prediction challenges for scientists.

Learning to communicate both what the findings are in those areas — and their inherent uncertainties — might help protect scientists from landing in court if their predictions turn out to be wrong. That also might help insulate scientists from the wrath of the public, which too often assumes that if a prediction is wrong, science doesn’t work and is corrupt.

Carolyn Y. Johnson can be reached at Follow her on Twitter @carolynyjohnson.