When the power went out during the blackout of Aug. 14, 2003, 50 million people across the Northeast, from New York City to Toronto, were left in the dark. And in a rare moment that night, looking up to the sky, people could see the Milky Way.
Roughly one-third of the world, including 80% of North Americans, are unable to see this bright band of stars that makes up the outer rim of our galaxy. Without light pollution, about 2,500 stars should be visible to us at night, but in most suburbs only a few hundred can be spotted with the naked eye.
The artificial light we live with — beaming down on our sidewalks, flooding the roads and rising up in a glowing dome over the land — affects everything from our sleeping habits (and with that our physical and mental health) to the nocturnal eating, mating, migrating and pollinating habits of many bats, birds and bugs.
Some places, however, are taking action to protect the night sky. In the United States, at least 18 states, as well as the District of Columbia and Puerto Rico, have laws to reduce light pollution. Communities are increasingly taking steps, such as consulting with ecologists on lighting design and designating remote areas as dark sky preserves, to protect this vital, yet overlooked, natural resource.
Four years ago, Fort Collins, Colorado, set a simple goal: a darker night sky as part of a broader effort to connect residents to nature.
Currently, the local government is working on establishing important baselines: How bright is the city now, and how much darker should it be? It’s also rethinking building codes, establishing connections with developers and educating the public about the importance of dark skies so that it can turn its simple goal into clear, achievable targets — all while maintaining public safety.
“I think people are still very much learning,” says Ginny Sawyer, project and policy manager for the city of Fort Collins, of public awareness around protecting the night sky. “[They’re] learning about the idea of why it’s even important or why it might be important or be of value. I think we’re still in our infancy there.”
The majority of Europe (88%) and nearly half of the United States (47%) lives with light pollution each night where the sky is 8% brighter than it naturally would be. From 2012 to 2016, the amount of artificially lighted areas around the world grew 2.2% each year, according to satellite data — that’s 11% over five years.
Some research suggests the pace of growth in light pollution matches the rates of urbanization. Experts also point to our rapid switch to LED lighting, a well-intentioned push for energy efficiency that is now leading to unexpected effects on humans and wildlife.
Our dark skies — and the many benefits they bring — are at risk. “It’s not just the night sky, but it’s the entire nighttime environment,” says Amanda Gormley, director of communications and public outreach at the International Dark-Sky Association. “It’s a whole system that’s really necessary for the health and wellbeing for all living things.”