Cascading Catastrophes

In an article some years ago, my colleague Bob Jaffin suggested that the difference between homeland security and emergency management was one of focus; while homeland security targeted threats external to the country, emergency managers concentrated on internal threats to the communities they served. This internal focus is completely understandable but can blind one to threats that originate externally but create cascading effects that have an impact on local communities.

The recent eruption of an underseas volcano in Tonga is an example of this problem. Although occurring some 5,000 miles away, the tsunami wave generated by the eruption caused an estimated $6.5 million in damages to the harbor in Santa Cruz, California, and the need for numerous rescues of surfers and sightseers.

 While the damage to the West Coast was slight, events with widespread impact are the literally the stuff of legend:

• There is a hypothesis that the Black Sea may have been formed by a catastrophic rise in sea levels around 5600 BCE, an event that may have served as the basis for the story of Noah’s ark and other legends of a great flood.
• The eruption of the Thera volcano circa 1600 BCE may have led to the fall of the Minoan civilization and the legend of Atlantis.
• A recent report on archeological excavations in Tell el-Hammam, Israel, suggest that an asteroid struck the area around 1650 BCE, possibly giving rise to the biblical story of the destruction of Sodom and Gomorrah.

There are numerous examples of global catastrophes in the geological record. Volcanic eruptions occurring some 250 million years ago are thought to have caused an event known as the “Great Dying” that saw the extinction of 70% of land species and 90% of ocean dwelling species. Volcanic events that created “volcanic winters” resulting in global famine are recorded throughout history. An eruption in 535 CE produced what has been considered the most protracted period of global cooling in the northern hemisphere in the past 2000 years. An event in 1257 CE followed several other smaller eruptions is thought to have ushered in the “Little Ice Age” that lasted until the 19^th Century. The eruption of Krakatoa in 1883 was one of the most destructive events in recorded history, with the explosion heard up to 3,000 miles away. It produced a volcanic winter that reduced the global temperature by .72°F and produced record rainfall in Southern California.

Catastrophic events that produce cascading effects are not limited to pre-20^th century history, of course. The eruption of Mount Pinatubo in the Philippines 1991 produced a volcanic winter that reduced overall global temperature by .7°F, reduced the ozone layer, and may have contributed to the Midwestern floods of 1993. In 2010, the eruptions of Eyjafjallajökull in Iceland created the highest level of air travel disruption since the Second World War when it forced the closure of European airspace for several days.

Clearly many of the historical events I have cited are extreme and beyond the capability of local emergency management response. However, smaller events are both predictable and within our ability to prepare for and mitigate, as the Eyjafjallajökull and Tonga events demonstrate. The cities and towns on California’s West Coast, for example, recognize the tsunami threat and plan for evacuation, building on existing plans and public warning protocols.

Emergency managers know that disaster planning is driven by limited budgets and consequently there is a need to prioritize those events that present the highest risk. How then do we plan for cascading events produced by catastrophes that may occur on the other side of the world? I suggest a two-pronged approach. First, acknowledge the possibility that such an event could occur and recognize the significance of events that occur outside your jurisdiction. Factor this into your hazard identification and risk assessments. Second, build flexibility into your existing plans based on that risk. You don’t necessarily need specific contingency plans for these events, but you should be able to recognize and react to emerging threats by adapting existing plans. Consider the problem of ash cleanup after the Mount St. Helens eruption in 1980 and the application of existing debris removal plans by local jurisdictions.

Remember, all-hazard planning doesn’t mean have a plan for everything, it means consider risk and be prepared to respond to threats, even those that take us by surprise.