Thursday, August 12, 2010

Living on Borrowed Land

redwoods

Why do mature redwood trees have trunks that rise two hundred feet before branches commence, live for centuries and have bark that’s a foot thick? Because they are adapted to fire.

zaca

Why does the silver-green chaparral that covers California’s hills and mountains burn so easily? Because it’s supposed to.

calpoppies

Why, other than its color, is the California Poppy such an appropriate flower for the Golden State? Because it is adapted to both fire and earthquakes. Says Wikipedia, “It grows well in disturbed areas and often recolonizes after fires”.

Of course, so do we. That’s why it’s not weird to find humans colonizing hillsides and other “disturbed areas” of California. Case in point: I am writing this in a house sited on an former landslide, not far from the perimeters of two wildfires that claimed hundreds of other houses in the past few months.

Every spot on Earth is temporary, but California is a special example. As permanence goes, California is a house of cards.

For example, take a look at some of the animations here, prepared by geologists at UCSB. Watch as a sheet of crust the size of a continent gets shoved under the western edge of North America. Debris that piled up in the trench where that happened is what we now call the Bay Area. Submerged crust that melted, rose and hardened under North America — and was just recently exposed — we now call the Sierras. Take a look at the last 20 million years of Southern California history. It’s a wreck that’s still going on. One section of that wreck is a bend along the boundary between plates of crust. Mountains pile up along that bend, like snow in front of a plow. The biggest of these ranges we call the San Gabriels. Those are on fire right now. Add up all the Southern California wildfires over the last twenty years and you’ll get a territory exceeding that of several smaller states.

My point is perspective. The human one is so brief that it can hardly take in the full scope of What’s Going On, or what our lives contribute to it. In a geological context, what we contribute are carbon and fossils. We do that by dying. Other planets have geologies as well, but none have marble, limestone, coal or oil. Those are all produced by dead plants and animals. It would be hard to make heat on Mars because — as far as we know — there is no dead stuff to burn.

Humans love to make structures and produce heat, which means we have an unusually strong appetite for dead stuff. Even cement and steel require dead stuff in their making.

If you fly a lot, as I do, you start to notice black lines on the landscape. These are coal trains that move like ant trails from mines in the West to power plants all over the country. The largest of these mines are in Wyoming, more than 50% of which has coal to burn. This coal consists of dead stuff that has been buried for dozens of millions of years, and took at least as long to form. In Uncommon Carriers, John McPhee says the largest power plant in Georgia, Plant Sherer, “burns nearly thirteen hundred coal trains a year—two thousand miles of coal cars, twelve million tons of the bedrock of Wyoming.”

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