That's the amount of coal that the U. S. burns every year to light up the bottoms of clouds. Call it 23 million barrels of oil if you prefer. Either way, it's a gargantuan waste of fossil fuels - resources that history may one day judge us harshly for consuming with abandon.
Some energy consumption, of course, is hard to avoid - are you going to tell your boss that you were an hour late for work because you were trying to minimize your carbon footprint? And who among us in the so-called First World will voluntary spend evening hours in darkness, forgo medical advances, and eat a hunter-gatherer's subsistence diet?
But much is simply wasteful. Take the kinetic energy - energy associated with motion - that each of our cars and trucks contain whenever they are on the move. A traffic light turns red, and bam! we hit the brakes, instantly converting hundreds of thousands of joules of kinetic energy into useless heat. The light turns green, and bam! we hit the gas pedal and burn another dollop of gasoline merely to return to cruising speed.
Hybrid cars now capture some of this kinetic energy and use it to charge their batteries; and very small cars reduce the amount of fuel that has to be spent to get them up to speed in the first place. But replacing our nations' fleets' of automobiles itself is an energy-hungry activity that also relies on environmentally disruptive mining activities. (Did you know that half of the world's known deposits of lithium - an essential component of rechargeable batteries - lie under dry salt lakes in the altiplano of Bolivia? Until I read this New York Times article, I sure didn't!)
And then there are the aforementioned six million tons of coal. The developed world is awash with waste light - streetlights, headlights, porch lights, security lights, and myriad other electrically powered fixtures that are:
- poorly shielded, so that they light up many things besides their intended targets;
- relatively poor at converting electricity into light;
- simply unnecessary (do the lights need to shine in your 60th-floor office at 3 a.m.?);
- ecologically harmful (millions of migrating songbirds are killed or disoriented by illuminated skyscrapers and offshore oil-drilling platforms);
- and counterproductive (glare from poorly shielded streetlights actually makes it harder for drivers to safely pilot their cars at night; poorly shielded security lights hide criminals while illuminating their victims).
Not only do the six million tons cost money and deplete a nonrenewable resource; their mining and combustion both cause serious environmental harm.
But perhaps I protest too much. After all, this blog is being written on a laptop computer with a far more powerful (and therefore power-hungry) processor than needed for the task; I transmit it to the Blogger web site using a power-hungry wireless card; and its bits and bytes probably reside on one of Google's gargantuan server farms. An interventionist might ask that energy be taxed to reflect its environmental costs; a libertarian might prefer that its production not be subsidized (arguably the cost of the U. S. war in Iraq, and our military presence elsewhere in the Middle East, is above all a subsidy for oil prices). Either way, it's a rare (albeit admirable) inhabitant of the First World who voluntarily forgoes all non-vital use of electricity in hopes of improving our planet.
P.S. Visit the website of the International Dark-Sky Association to learn about how you can help save energy and the night sky.
Copyright 2009 Joshua Roth.