Highlighter in hand, I was ready to cross off the aurora borealis from my bucket list. The Northern Lights, that shimmering celestial curtain of charged particles crashing into Earth’s atmosphere, was scheduled to make a rare appearance in the southern Michigan sky on St. Patrick’s Day. A particularly awesome coronal mass ejection (CME) from the sun was going to extend its ionic spectacle far beyond its usual stomping ground. My local meteorologist was hugely excited. He instructed all interested parties to head outside between midnight and 1:00 a.m. and gaze upward at the crystal clear sky.
I did as I was told. Indeed, the sky was clear. Bright twinkling lights of airplanes abounded, a star or two shone in the distance. But the Northern Lights?
My bucket list didn’t stand a chance. There was too much darn light pollution. That orangey urban glow is a pestilence that rarely bothers me, but now I was nonplussed that my Irish holiday would end without the celestial equivalent of green beer.
It was time I took light pollution seriously, as so many others already do. I’d never really thought of it as real pollution, like, you know, air pollution or water pollution. Lack of true darkness in urban areas was an issue, to be sure, but the nuances escaped me. Turns out that what I was witnessing is called sky glow, one of the four main types of light pollution (glare, light trespass, and clutter are the other three). Here’s the skyglow of Istanbul in all its glory:
It’s not only amateur astronomers like me who shake their fists at excess night light when trying to locate the Big Dipper, but also the professional astronomers. Turns out their telescopes can’t filter out light and clouds, as I always thought they could. The Mt. Wilson Observatory in Los Angeles, for example, is only 11 percent as effective as when it was built in 1908. Even Keck Observatory on Mauna Kea in Hawaii, a state-of-the-art facility in the middle of Pacific Ocean, suffers from serious light pollution problems.
But this inconvenience to scientists is nothing compared to what night light does to birds and other nocturnal animals. When artificial life interferes with their biological processes, it’s called ecological light pollution. It is an actual life-or-death matter. Even plants can suffer, because some need total darkness as well as sunlight in order to thrive. For example, there’s a species of zooplankton that refuses to eat unless it’s super dark outside. They normally feast on algae, but when they don’t eat, the algae multiply unimpeded. Algal blooms flourish, marine life suffers.
Ecological light pollution messes up the predator-prey relationship of nocturnal animals. If it’s a frog’s benefit that it can see in the dark and its prey can’t, what happens when it’s never dark? The frog loses its advantage and the species suffers. Then there’s the whole system of moths and nighttime insects, along with night-blooming flowers, that can collapse. If moths have trouble navigating, they get lost on their way to the night-blooming flowers, which then do not become pollinated.
Then there’s towerkill. This is when birds become disoriented by lights on tall buildings and towers, such as cell phone towers and TV antennas. They can collide “with other birds, structures or windows, or [circle] the lights until they die of exhaustion.” The U.S. Fish and Wildlife Service says that 4 to 5 million birds per year succumb to nighttime towerkill. Especially affected are juvenile seabirds leaving the nest for the first time and migratory birds whose navigational instincts get turned around in the brightened night sky. In Toronto, the Fatal Light Awareness Program (FLAP) urges building owners to turn off tower lights and for residents draw their curtains at night during migratory periods. This seems fine and dandy until you think about all those airplanes flying around in the dark. What happens to them without those flashing red lights?
Additionally, towerkill is child’s play compared to the number of birds who die each year by flying into windows in broad daylight. That number is supposedly between 100 and 900 million per year. With all due respect to ornithologists and bird lovers everywhere, eliminating light pollution won’t solve this even bigger problem. Not to mention the fact that these statistics raise a host of questions: Why don’t I see dead birds everywhere I turn? Can you narrow down your margin of error? Has the problem lessened with the widespread dismantling of TV towers in recent years?
Then there’s the poor sea turtles. They’ve suffered so much! Not only does light pollution interfere with the female turtles laying eggs, but also little baby turtle hatchlings are programmed to navigate to the sea in the dark, moving away from the dark silhouettes of vegetation and toward the water. When beaches are lit, they don’t know where to go—not to mention that they become tasty snacks for predators.
Lastly, Homo sapiens also suffer from light pollution in the form of headaches, fatigue, stress, and anxiety. Light pollution interferes with sleep and melatonin production. If you don’t care about the birds (but you should), at least you care about your own zzzz’s, right?
The good news is there is lots we can do to eliminate excess light pollution, which would be good for the wallet as well as the environment. Lighting up the sky unnecessarily costs somewhere in the neighborhood of $1 billion each year in the U.S. alone. Diverting or killing some of this light will result in a darker sky.
Some of the solutions to light pollution are pretty simple. Here’s a list from the Prairie Astronomy Club in Lincoln, Nebraska:
- Use the right amount of light, not overkill.
- Shield the light so that is goes down, not up or sideways.
- Use light timer controls whenever possible.
- Use low-pressure sodium fixtures whenever possible because it is the most energy efficient and because its light can be filtered out with telescope filters.
- Avoid using round globe lights unless they are properly shielded.
Another great resource is the International Dark-Sky Association, founded in 1988 to promote the idea of lighting what you need, when you need it. They initiated the International Dark Sky Places Program, which lists the locations you’ll want to be in the next time the aurora borealis finds its way south of the 45th Parallel. In fact, mark your calendar now, because International Dark Sky Week takes place from April 13 to 18, 2015. Here’s hoping I don’t see you there.
Kathy Wilson Peacock is a writer, editor, nature lover, and flaneur of the zeitgeist. She favors science over superstition and believes that knowledge is the best super power. Favorite secret weapon: A library card.