Like it or not, we've become a 24/7 society — and, like it or not, nighttime activity requires some illumination to help us find our way along streets and sidewalks.
But it's easy to see that very little outdoor lighting is done well. Too many fixtures send light streaming up into the sky, or provide far more light than is necessary, or are simply left on when they're not needed. For all these reasons, light pollution has become the universal bane of anyone who appreciates the starry sky.
Five years ago, a high-school student named Jennifer Barlow decided it was high time to raise our collective consciousness about the growth of light pollution. So she launched National Dark-Sky Week. The event has been gaining steam every year, and it's gained the endorsement of the International Dark-Sky Association, the American Astronomical Society, and the Astronomical League.
This year National Dark-Sky Week runs from March 29th to April 4th. It's timed to coincide with Earth Hour, another night-sky-friendly effort sponsored by the World Wildlife Fund. To participate in Earth Hour, simply turn off unnecessary lights (particularly outdoor lights) in your home or business from 8 to 9 p.m. on March 29th.
That small effort is more than just symbolic — it will achieve a small but real saving in electricity and, in turn, the coal or oil that's likely being burned to create it. And the simple act of identifying a light to turn off might convince you that it didn't need to be on in the first place, or at least that it doesn't need to be on all night long.
Did you know that keeping a single 100-watt light bulb on all night, every night, requires more than 400 kilowatt-hours of electricity each year — the energy equivalent of burning more than 500 pounds of coal, and costing you (typically) more than $50 per year?