Photograph courtesy of NASA
Now that the days are getting shorter, our lights burn brightly later into the morning and earlier in the evening. There may be no better visual reminder of where humans live on the planet than a photograph of the earth at night. Cities shine, suburbs twinkle, and the few remaining locales that don’t glow with electricity look both desolate and peaceful. Despite our love of light, so-called light pollution can have detrimental effects to wildlife and humans. That’s why the National Park Service and the International Dark-Sky Association, a nonprofit focused on preserving the night, protecting wildlife, and conserving electricity, have begun to identify dark sky reserves across the world.
Artificial lights can confuse turtle hatchlings trying to reach the ocean, divert migratory birds, and distract bats (PDF). Salamanders that search for food at night are less active and experience lower reproduction rates when there is more light pollution, and tree frogs stop calling for mates.
Not only that, but research shows that artificial light can also suppress the release of melatonin, a hormone that both regulates other hormones and helps us maintain our circadian rhythm. In a report published this year from the American Medical Association’s Council of Science and Public Health, researchers stated (PDF) that, “limited epidemiological studies support the hypothesis that nighttime lighting and/or repetitive disruption of circadian rhythms increases cancer risk.” Most research on the topic has been in relation to breast cancer, but more study is needed, they said.
To counter some of these negative effects, the International Dark-Sky Association designated places like the NamibRand Nature Reserve, the English Channel Island of Sark, and a large section of New Zealand’s South Island dark sky reserves. The National Park Service also has a Night Skies Program that brings attention to the issue of light pollution and keeping sections of the country in the dark.
Specialized lights and new technologies can help direct beams downward or switch them off altogether. “Controlling street lighting, right down to individual lamps, could soon be possible thanks to intelligent lighting systems. They use wireless technology to control lights from a central management system. It means at any time lamps could be adjusted in response to weather, circumstance and individual need. Sensors, texting and email could be utilised to convey the information,” the BBC reported earlier this year.
So far, experts like Chad Moore with the National Park Service, are saying that a growing number of people are becoming aware of the problem. “I’ve never been involved in anything that has been like this project,” he said in 2008. “It’s to the point now where I don’t feel like I’m pushing it, I feel like it’s pulling me. When we started, I would give a talk and ask the audience how many had heard of light pollution before. Very few people would raise their hand. Now it’s always the majority of the audience—in just less than eight years. There are a lot more options for night sky-friendly lighting fixtures out there: ones for your porch, for cities, for businesses. And almost every manufacturer has a selection of lights. It’s up to the people installing these, from the homeowner on up. Just take a little bit of time to learn a little bit more about it and see if you can make a greener choice.”