Voices: Italian seismologists: What should they have said?

by John C. Mutter
Friday, January 20, 2012

In Italy, seismologists who failed to predict the L’Aquila earthquake in 2009 could face manslaughter charges. On March 31, 2009, the Major Risks Committee — composed of six seismologists — told the rest of the Civil Protection Department (pdf) and other officials that there was “no reason to suppose a sequence of small earthquakes could be the prelude to a strong event” and that “a major earthquake in the area is unlikely but can’t be ruled out.” In other words, they did not recognize as precursory the sequence of earthquakes in the months that preceded the fatal event of April 6.

Did this warning constitute negligence on the part of the scientists? The troubling answer is: yes and no. Basically, although entirely accurate scientifically (it is impossible to tell whether a small earthquake is a precursor until after a larger one has occurred), what they told the public was not very helpful, and it is not entirely surprising that people in Italy are now angry at their seismologists for being so unhelpful. The feeling seems to be that scientists should have known, and that the evidence was there in front of them and they dismissed it.

This echoes of the current debate about the BP incident in the Gulf of Mexico in which it is now inevitably being said that warning signs were ignored. A sequence of events on the Deepwater Horizon that many people will now say were clear warnings — precursors — were either not recognized as such or ignored. In both cases a disaster followed. There is sure to be litigation against BP and no one will question the merit of the legal actions.

Compare the very cautionary approach of seismologists to that of climate scientists. At the opposite extreme, many climate scientists are sounding clear warnings of global warming with dire claims as to what the consequences may be for the planet and human future on the planet. These scientists are shouting at the public and the public isn’t listening. More likely is that the public doesn’t quite know what to do: You can drive a Prius and install curly light bulbs but it doesn’t seem to stop scientists from shouting about the problem.

Most of what climate scientists are saying is also based on precursors of a sort. There is reasonably good scientific theory too. The basic physical chemistry of the greenhouse effect is well-established, but the size and sense of myriad feedback effects that could enhance or diminish the primary effect is not as well-established, nor is the strength and sign of the radiative forcing of some components of the atmosphere.

This leads to quite a bit of uncertainty, but the issue is usually cast in terms of just how bad things could get — “not so bad” or “really terribly bad.” The language sounds a little like seismologists if you step back and think about it a bit — except that climate scientists are saying they really are seeing precursors, but exactly what they are precursory to is hard to say.

What’s more, the precursors look weak to most people — things like tiny rises in sea level that need fine instruments to record, barely perceptible changes in ecosystems that don’t seem to be harmful, and the retreat of glaciers that most people have never seen nor ever will. The public sees what amounts to very small or very distant changes and is asked to believe that they are premonitions of a future catastrophe. It is no surprise that most people are at least a little skeptical.

And what if the opposite happens to the climate? What if governments and individuals take all manner of costly measures to reduce greenhouse gas emissions and the predictions don’t come true? Can the public seek retribution from scientists for wasting their money on something that amounted to a wrong prediction because they misread the precursors? I doubt any scientists who are currently shouting about global warming would be willing to accept those terms.

If global climate were to go awry, real trouble lies ahead for billions of people, so climate scientists tend to work on a precautionary principle. The argument is that if it is possible that things could become really bad, we should act to avert that possibility even if we could be wrong about just how bad it might get. If things were to get as bad as they plausibly might, it would be very difficult to repair after the fact. We shouldn’t hand people of the future a problem that we could have fixed in the present. Indeed, this seems a very sound way to act.

Seismologists take quite a different approach to the precautionary principle. Seismologists tend to say that we can’t predict specific events — and that is true, though we tried for a long time and the public never tires of asking whether one day we will be able to make predictions. Instead we talk in terms of “probabilistic risk assessments,” and the public is completely lost. We are forced to say things like the Italian scientists had to say — “maybe there will be an earthquake and maybe there won’t be an earthquake.” I haven’t read the report from the committee; perhaps they even gave probabilities that no one knew how to make sense of.

So what should scientists say if the truth is they are quite uncertain about what might happen in the future, as is usually the case? It is a real dilemma for us, but I think there is a need for plain talk.

First, if we really don’t know something, we should say we don’t know (climate scientists and seismologists), and not cloak that statement in hyperbole that might satisfy our fellow scientists but is of no use to anyone else. We can say that a sequence of small earthquakes could portend a major quake (because they have in the past), but we can’t say where or when or even if, as there are countless times where such series of tremors led to nothing. We need to make sure the public understands what we can and can’t reasonably say.

Second, and more importantly, we need to remind people of what to do if and when they feel the ground begin to shake. Remind them to have supplies of food and water, a flashlight, etc. Remind them to hide under a table or get in a doorway — all the things we know can save lives in an earthquake. We can tell people about earthquake survival strategies in simple plain language without hyperbole and people can do what we suggest.

People will do nothing at all if we frighten them but give them no guidance on what action to take. Worse, they will go into denial. And they will certainly do nothing if what we say is equivocal. If you are prepared and nothing happens that’s a bother and a letdown maybe, but ultimately not a big deal. There is no harm in having a good flashlight anyway. If people take no notice, there isn’t a lot we can do about it. People will die no matter what we say, but perhaps fewer people would have died if we had just reminded them of the simple things that are known to save lives.

Ultimately, that’s what the Italian seismologists should have said. And if they had, some use could have been made of it and no one would be facing charges — in theory anyway.