November 12, 2008

Oh, boy, it's the end of the world!

As illustrated in Vexille, a perverse pride in we humans ending the world as we know it lies at the heart of the modern techno-panic. Nuclear winter and global warming are ultimately celebrations of how dastardly clever we are in all our "Dr. No" evilness. The malevolent and laughably efficient IT capabilities of the government on display in Enemy of the State is a cinematic case in point.

The superhero is only as good as the supervillain is bad. Ordinarily incompetent governments and their fumbling, bumbling agencies are a bunch of killjoys (but do just as much damage).

In any case, nature's got us beat in the long run. To be sure, the sun has a few billion years of life left in her, and very few of the stars in our galactic neighborhood could possibly produce a gamma ray event capable of turning us into beef jerky. We currently possess the technology necessary to detect and deflect a killer asteroid (though it wouldn't be as interesting as in the movies).

But not all global extinctions are caused by asteroids or gamma ray events. Ice ages make repeat appearances, with the last glacial maximum occurring a mere 20,000 years ago. For starters, all those pretty glaciers would make Canada, the northern U.S., Northern Europe and Russia uninhabitable. The agricultural carrying capacity of the planet would fall by several orders of magnitude.

But ice ages are slow and boring, as are the IPCC's worst-case global warming scenarios. On the other hand, supervolcanoes have triggered the atmospheric equivalent of asteroid strikes within the span of human evolution (Lake Toba, Indonesia, approximately 75,000 years ago). A few hundred miles from where I live, Yellowstone Park sits on top of an active supervolcano caldera.

The fun and exciting thing about supervolcanoes is that they're definitely not glacial, and unlike asteroids, there is no way to predict a supervolcano eruption to within the error of a human lifetime, or to prevent one from erupting, or to stop one once it has. The next time a Lake Toba or Yellowstone lights up (and one will one day), life as we know it is basically toast.

Sweet dreams.

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# posted by Blogger Damien Sullivan
Actually I'm not certain of all that. There's tremors and gas buildup, or at least rising ground, to detect, and I can imagine drilling down to relieve pressure and let magma and gases out on a gradual basis. Even if that ended up triggering the eruption, there's something to having a supervolcano go off on our schedule rather than its: stock up on several years of food supply, evacuate large areas or have people in shelter with tools to keep air vents clear, be prepared for cleanup, etc.

It's worth noting that the total geothermal heat flux of Earth is a few times 10^13 Watts, about twice total human energy usage (not counting sunlight captured by crops and the water cycle.) My estimates of the average power of a volcano or big earthquake (energy divided by time between events) tend to be in the gigawatt or even megawatt range, comparable to a municipal power reactor or smaller.

* Other threats: big long term eruptions, like the Deccan Flats, causing high CO2 levels and mass extinction. Possibly 'gradual' and fixable by industrial drawdown of CO2.

* Canary Island tsunami sweeping the Atlantic. Possibly 'fixable' by setting it off on our schedule.

Ice ages have probably been banished for the indefinite future, not that we were close to having the next one.
11/17/2008 12:11 AM