Monday, May 23, 2011

The danger zone

Yesterday, a tornado tore through the town of Joplin, Mo., a couple of hours away from the city where I grew up. Dozens of people already have been confirmed dead, and the damage is massive--neighborhoods destroyed, stores leveled, a hospital gutted.

It is an awful scene.

Yet it is interesting looking at the perceptions of the devastation in the eyes of the world media. Outside the U.S., it almost appears sometimes as though the Midwest United States is just a snakepit of deadly tornados, and every city will be hit eventually. I think that is partially because tornados are so rare outside the U.S., and because they really only make news outside the country when they are horrific.

But in fact, although there 1,266 tornados in the US in 2010, only 45 people were killed. All of those deaths are tragic, but it shows how rarely a twister hits a populated area. (which is simple odds, by the way: most of the country is unpopulated, making it unlikely a city will be hit) Indeed, the Netherlands has the most tornados per square mile in the world... yet rarely are there fatalities.

I recall an exercise from a high school class, in which we were divided up into groups, like tribes, and told to find a place to settle on a big map of a fictional continent. Every area had natural hazards--earthquakes, floods, heavy snows, electrical storms and, yes, tornados.

Everyone worked really hard to place their settlement in an area without any natural hazards. But in every case, that was not only almost impossible to do, but an area without any hazards inevitably lacked resources like water and fertile soil. Then the teacher pointed out the obvious: that these hazards really weren't that hazardous at all in the grand scheme of things. No civilization has ever been wiped out by lightning strikes. And some, like ancient Egypt, thrived by living right on the edge (and sometimes square in the middle) of a flood plain.

The one exception I'll give you is volcanos. They have a long, proud history of wiping out civilizations.

Anyway, my point here is this:

No matter how dangerous "Tornado Alley" sounds, it's actually a pretty safe place and some of the most fertile soil in the world. Living there is not like building your house in the path of a freight train... it's more like betting that a freight train several blocks away won't derail, go airborne and land in your backyard. It has been calculated that any one neighborhood (like a square mile or so) will be hit by a tornado once every 2,200 years. A serious tornado, one with winds faster than 150 mph, is more like once every 7,000 years.

The town of Joplin will recover from the devastation. And cities across the United States and the world will continue to thrive in the face of wind, floods and earthquakes. Human beings are just resilient that way.

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