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By Michael Lucibella
In the early morning of April 6, 2009, a magnitude 6.3 earthquake decimated the ancient town of L’Aquila in central Italy. After the tremors stopped, 309 people were dead and a city was left in mourning. Three and a half years later, six scientists and a government official were convicted of manslaughter connected to those deaths.
Within the scientific community, the verdict sparked fear and outrage, but also reflection about the importance of effective communication. Many geologists and physicists who study the risks of rare events have criticized the government of Italy, but have called as well for more effort by scientists to educate the public about understanding the nature of risk.
Headlines around the world proclaimed the Italian government was persecuting scientists for not doing the impossible, predicting an earthquake. However, the case against them was more complicated than that, and from the outset, prosecutors denied that the scientists were being charged on scientific grounds.
“I’m not crazy… I know they can’t predict earthquakes. The basis of the charges is not that they didn’t predict the earthquake. As functionaries of the state, they had certain duties imposed by law: to evaluate and characterize the risks that were present in L’Aquila,” L’Aquila’s public prosecutor Fabio Picuti told Nature News before the trial.
The victims’ family members, who brought the case against the scientists, echoed this sentiment, saying that the scientists offered little information about the earthquakes and what was disseminated was contradictory and confusing.
In the months leading up to April 6, the city of L’Aquila had been repeatedly shaken by tremors, sparking fears that “the big one” would soon come. Many residents were sleeping outside, worried that their homes would collapse around them if a large earthquake hit. Adding to this anxiety, a technician at Gran Sasso National Laboratory, Giampaolo Giuliani, had been grabbing headlines by predicting a big quake was just around the corner, alarming the residents. However, Giuliani based all of his predictions on a supposed increase in radon levels, a method that geologists and seismologists say has no basis in science and is not a reliable predictor of earthquakes.
The government of L’Aquila convened a special session of the National Commission for Forecasting and Predicting Great Risks essentially to debunk Giuliani’s claims. The commission agreed that Giuliani’s radon technique was not a reliable method to predict earthquakes, and added that there was only a one to two percent chance that the cluster of quakes was the precursor to a big devastating quake.
There was no formal written statement issued by the group, leaving the public to rely on statements to the press made by its members before and after the meeting. The most notorious statement to the press was made by the government official Bernardo De Bernardinis, formerly the Vice-Director of the Department of Civil Protection. When asked if the tremors meant a bigger earthquake was coming, he said “the scientific community continues to assure me that, to the contrary, it’s a favorable situation because of the continuous discharge of energy.”
There is some debate as to whether he made this statement before or after the meeting. According to the meeting’s minutes, the energy discharge theory was not addressed and no scientists publicly disputed his statement. During the trial, several of the scientists said that they strongly disagreed with this interpretation and that it was not scientifically accurate.
The committee did not release any risk assessments of the local buildings and infrastructure, or recommendations to the public on what to do if a large earthquake did hit. The essential message the public seemed to get in the information vacuum after the meeting, was that there was no danger.
A week later, however improbably, a 6.3 magnitude earthquake did strike, leveling 20,000 buildings, leaving 65,000 people homeless and 309 dead. Civil parties to the case against the scientists claimed that they and their loved ones didn’t evacuate their houses because of the apparent assurances reported in the press.
Scientists and scientific societies the world over have denounced the verdict. The American Association for the Advancement of Science and the American Geophysical Union (AGU) have both released statements criticizing the trial.
“For scientists to be effective, they must be able to make good faith efforts to present the results of their research without the risk of prosecution,” the AGU statement reads. “Outcomes such as the one seen in Italy could ultimately discourage scientists from advising their governments, from communicating the results of their research to the public, or even from studying and working in various fields of science.”
The fear is that the verdict will have a chilling effect on science in Italy.
“I’m really scared to do anything, to say anything,” said Warner Marzocchi, a seismologist at the Istituto Nazionale di Geofisica e Vulcanologia in Rome. He added that what worried him the most were the charges of negligence against the accused scientists because there are no real best practices for communicating a forecast.
“Negligence to me sounds very strange. You can talk about negligence when there is best practice, like with doctors,” Marzocchi said. “In almost all countries there are essentially no protocols to deal with such a problem.”
Laws about public speech in Italy are different from those in the United States, and few think that the verdict has the same chilling potential here.
“In the geophysics community, we are all sort of making the joke that Italy is the one place we’re not going to be doing predictions because of this,” said Joel Tenenbaum of Boston University.
However, many scientists feel that the public response highlights a lack of comprehension about risk and rare events, such as not understanding that saying something is unlikely does not mean it will never happen.
“The fact is that the public is not educated at all about risk when something is random like earthquakes,” said Gene Stanley, who studies statistical physics and rare events at Boston University. “The public has to become educated about risk.”
John Rundle, a geophysicist at the University of California, Davis who also runs the risk assessment group Open Hazards, said that when talking about earthquakes and other hard-to-predict catastrophes, scientists need to emphasize the statistical nature of a prediction, and how a rare event is not an impossible event.
“Be careful how you phrase your warnings and forecasts, phrase them probabilistically,” he advised. “It’s our job to educate the public and we need to just put a lot of data out there… If they can’t sort through it, it’s our job to help sort through it.”
How best to communicate this kind of nuanced information to the public is not plainly obvious. Overzealous warning can unnecessarily frighten the public, or worse lead to distrust of experts after too many unrealized warnings. At the same time, experts don’t want to conflate unlikely with impossible.
“It’s very easy to be flip,” said Kristy Tiampo, a professor of earthquake hazard assessment at Western University in Ontario. “The real issue is how you communicate what you think might happen. But how do you put a number on that, and how to communicate to the public the error on that?”
There’s no single simple answer, but it’s a subject the scientific community is taking seriously and addressing in the wake of the Italian convictions.
“We’re going to explore this a little bit more,” said Christine McEntee, Executive Director of the AGU. At the society’s meeting this month, they’re planning on having a special session about communicating geological risk assessment. “There’s a lot of room for improvement in communicating science in effective ways.”
An important part of this communication is explaining the limits of what science can do.
“The average person is attracted to science because of the desire we all have for certainty,” Stanley said. “Science is a reassuring thing, but there are things scientists work on that are anything but assured.”
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