Only in hindsight does earthquake prediction work with real accuracy. Seismologists can assess long-term risks and likely scenarios, but they'd be the last ones to say they can foretell the time, date and epicenter of the next Big One. Yet in Italy, a trial is underway for a group of seismologists and a government official accused of manslaughter for being overly reassuring about underground rumblings that preceded a killer quake in 2009.
The charges they face for doing their job aren't just ludicrous but potentially damaging to scientists worldwide. Society increasingly relies on expert scientific advice; it won't receive that advice if scientists are afraid to speak.
The Italian official and seismologists, who make up a panel called the Commission of Grand Risks, had been asked to assess the risk in quake-prone L'Aquila, in central Italy, after a series of tremors. In a March 2009 memo, the commission concluded that a major earthquake was unlikely, though the possibility couldn't be ruled out. In addition, one member of the commission said, imprudently, that residents of the area should relax, preferably with a glass of wine. A week after the memo was released, a magnitude 6.3 earthquake struck, killing more than 300 people.
Modern society is apt to look at science as a sure thing. But scientific insight can neither take all the uncertainty out of life nor make people safe in all situations. What it does, more often than not, is guide us to better-informed decisions than we could obtain by blind guessing.
In this tragic case, the experts were wrong. But what if the commission had taken the opposite approach and told the public that the situation in L'Aquila was very dangerous and that everyone should evacuate immediately? In the rush to leave town, there could have been fatal car accidents; if the prediction was mistaken and there was no quake, lives would have been needlessly lost. The only safe answer becomes "I really don't know," which is of no help to anyone.
Obviously, scientists shouldn't be flippant about seismic safety. But Italy supposedly ended the business of prosecuting irreverence and science after the 16th century Inquisition. No matter what the verdict is in this case, the only possible outcome is a chilling effect on seismologists and any other scientists called on to venture an opinion in an uncertain world.