randolph_nesse's picture
Research Professor of Life Sciences, Director (2014-2019), Center for Evolution and Medicine, Arizona State University; Author, Good Reasons for Bad Feelings
The Fragility Of Complex Systems

On the morning of August 31, 1859, the sun ejected a giant burst of charged particles. They hit the earth 18 hours later, creating auroras so bright that at 1 AM birds sang and people thought morning had dawned. Currents induced in telegraph wires prevented transmission, and sparks from the wires set papers aflame. According to data from ice cores, solar ejections this intense occur about every 500 years. A 2008 National Academy report concluded that a similar event now would cause "extensive social and economic disruptions." Power outages would last for months, and there would be no GPS navigation, cell phone communication, or air travel.

Geomagnetic storms sound like a pretty serious threat. But I am far less concerned about them than I am about the effects of many possible events on the complex systems we have become dependent on. Any number of events that once would have been manageable now will have catastrophic effects. Complex systems like the markets, transportation, and the Internet seem stable, but their complexity makes them inherently fragile. Because they are efficient, massive complex systems grow like weeds, displacing slow markets, small farmers, slow communication media, and local information processing systems. When they work they are wonderful, but when they fail we will wonder why we did not recognize the dangers of depending on them.

It would not take a geomagnetic storm to stop trucks and planes from transporting the goods that make modern life possible; an epidemic or bioterrorist attack would be sufficient. Even a few decades ago, food was produced close to population centers. Now, world distribution networks prevent famine nearly everywhere…and make mass starvation more likely if they are disrupted suddenly. Accurate GPS has been available to civilians for less than 20 years. When it fails, commuters will only be inconvenienced, but most air and water transport will stop. The internet was designed to survive all manner of attacks, but our reckless dependency on it is nonetheless astounding. When it fails, factories will stop, power stations will shut down, air and train travel will stop, hospitals and schools will be paralyzed, and most commerce will cease. What will happen when people cannot buy groceries? Social chaos is a pallid phrase for the likely scenarios.

Modern markets exemplify the dangers of relying on complex systems. Economic chaos from the failures of massively leveraged bets is predictable. That governments have been unable to establish controls is astounding, given that the world economic system came within days of collapse just five years ago. Complex trading systems fail for reasons that are hard to grasp, even by investigations after the fact. The Flash Crash of May 6, 2010 wiped out over a trillion dollars of value in minutes, thanks to high frequency trading algorithms that interacted with each other in unpredictable ways. You might think that this would have resulted in regulations to prevent any possibility of reoccurrences, but mini flash crashes continue, and the larger system remains vulnerable.

These are examples because they have already happened. The larger dangers come from the hidden fragility of complex systems. James Crutchfield, from the Santa Fe Institute, has written clearly about the risks, but so far as I can tell, few are paying attention. We should. Protecting us from catastrophes caused by our dependency on fragile complex systems is something governments can and should do. We need to shift our focus from this threat and that, to the vulnerabilities of modern complex systems to any number of threats. Our body politic is like an immune compromised patient, vulnerable to massive collapse from any number of agents. Instead of just studying the threats, we need scientists to study the various ways that complex systems fail, how to identify those that make us most vulnerable, and what actions can prevent otherwise inevitable catastrophes.