Photo by Jason Hickey via Flickr.

The San Gabriel Mountains are some of the steepest on Earth. They’re geologically complex, riven by faults and scraped back and forth by plate tectonics. They are coming down.

I read about them in “Los Angeles vs. the San Gabriels”, the final essay in John McPhee’s The Control of Nature. McPhee’s description of the way the mountains’ unstable rock interacts with the local cycle of fire and flash-flood is chilling; what’s more disturbing is that at their feet, in the path of the debris flows, are expensive and expansive human settlements, sprawling bedroom communities of Los Angeles.

I highly recommend reading the book; in fact, I’ve already lent my copy to my family so they can read it, or else I’d be quoting more extensively. But my own reaction to the book made me think. Reading about families buying or building uninsurable multi-million dollar homes in the foothills of these moving mountains, I was incredulous. How could they live there just because it’s pretty and less smoggy than other parts of the LA Valley? How could they trust their lives and the integrity of their homes to the partial protection of a debris basin?

Photo by yikai1 via Flickr.

There are other stories in the book that mystify me as much. In “Atchafalaya,” the first essay, the author describes a city in Louisiana in a uniquely precarious position — “Water approaches Morgan City from every side.” (page 80) — one entirely dependent on the Army Corps of Engineers for the sea walls that protect them from flood. Years have passed since Control of Nature was published, so I went to check the city’s Wikipedia page to see how they’ve fared. The words ‘wall’ and ‘flood’ don’t appear; apparently no one deemed the dangers notable.

We all live with risks, calculated or ignored. It’s easy to disapprove of the choice to build new mansions in the foothills of the San Gabriels, and hard to understand the Caltech geologists who outline the dangers of the mountain front for McPhee and then admit to living there. Easy to condemn the citizens who shrugged off their town government’s attempts to educate them about the season’s high likelihood of flows, refused to engage in mitigation activity, then sued that city when flows devastated their property. But what of the hardy men and women McPhee interviewed who live in the mountains because they love nature, who know the dangers better than anyone and stand in defiance in order to live in the wilderness? Is it knowledge that makes risk-taking acceptable in the eyes of an observer? Is it love?

Photo by Barry Maas via Flickr.

I have lived most of my life in Oregon. I’ve known, most of that life, that there are dangers. The weather is generally mild, and floods are not too common or dangerous, but underneath the state it’s a different story. The Juan de Fuca and North American plates have been locked without a major earthquake since 1700. I’ve been told all my life that we’re overdue for a big quake, and learned in college that much of the earthquake proofing in the Northwest is proven against San Andreas style shaking, not the subduction zone movement it will someday need to withstand.

But I love Oregon. I want to move back there, and I accept the risk. When friends from the Midwest ask about earthquakes, I usually say, “Yeah, it’ll happen someday, and it may kill me, but it may not.” It sounds fatalistic, but it does represent my position: A quake will occur, possibly within my lifetime, possibly later. It is likely to be massive, so there’s a limit to how much I can do about it. It’s an omnipresent, huge threat, but its very omnipresence and size make it ignorable. I can’t stress about it every minute, and when it happens, I’ll either be too dead to care or able to stop fretting about it for the rest of my life. Living in San Jose concerns me a little more, but not worrying is a similar process here, pretty easy to accomplish.

But tornado season every year? Regular flooding of the Mississippi? Knowing that every time the chapparal on the mountains burns, two good rains in a row could move a hill down into my neighborhood? I couldn’t cope with those risks.

This isn’t just a question of my comfort levels and yours; of my childhood practicing earthquake drills and learning about the volcano that erupted nine months before I was born versus Ryan’s childhood of riding the schoolbus home playing ‘spot the twisters’. Our cities are crowded; people want to live on the fringe where rents are low, or in the foothills above the smog. People want to retire further away, to remote but growing towns vulnerable to forest fire. The rich want to build beach houses on shifting dunes, while others cannot afford to move out of the floodplain, out of the trailer park in Tornado Alley, out of the path of the Mississippi. Our world is crowded. And, as the ice caps melt, our field of options will get smaller.

We all underwrite each other’s choices. Within the US, by paying for rescue, for flood or high-risk home insurance, for disaster relief with our taxes. Across the globe, with international aid and our emotional investment in the lives lost at the edge. Who is going to decide what risks are reasonable? Whose freedom to risk can be respected, and whose should not? In this society of contradictions, where rugged individualism is espoused and habitual litigiousness is practiced, who has the right to decide where you or I make a home?