Have you ever wondered what light pollution is and/or whether it is a big deal? According to the International Dark-Sky Association (IDA), light pollution is “any adverse effect of artificial light including sky glow, glare, light trespass, light clutter, decreased visibility at night, and energy waste.” Wanting to learn more about this issue, I recently watched the documentary The City Dark. I am glad I did because filmmaker Ian Cheney did a wonderful job with this movie which features stunning astrophotography, easy-to-understand illustrations, and insightful and often humorous comments made by a variety of individuals including (but not limited to): an astrophysicist, boy scouts, a light bulb specialist, a cancer patient, and an epidemiologist. As an amateur astronomer who truly appreciates the dark sky, Cheney was able to offer a very personal, compelling, and unique perspective on the issues of light pollution and the disappearing stars, especially in highly urbanized areas like New York City.
After moving from rural Maine to light-polluted New York City, Cheney quickly learned that he could no longer see the stars, prompting him to really consider whether we needed the dark sky. The City Dark is his creative, emphatic response of “YES, we do!” As Cheney points out, reducing light pollution helps to make more stars visible at night, lessen the effects of unnatural lighting on the environment, and cut down energy usage. The film reveals with examples the negative effects of a world dominated by artificial lighting and increasingly lacking in dark skies. For example, I was previously unaware that exposure to excessive artificial light at night could: increase breast cancer rates; cause hatching turtles along the Florida coast to get lost and die; and result in birds flying into buildings, and then lying injured and helpless on Chicago streets.
Unexpectedly, this film also teaches us about humility, i.e. not focusing entirely on or thinking too highly of ourselves, but putting ourselves and our lives in proper perspective. Specifically, by looking at the stars and thinking about the greater universe, we should come to realize how little we know and how small we are in the grand scheme of things. This is a particularly important lesson and reminder in Los Angeles where people tend to be rather obsessed with Hollywood and are much more interested in movie stars than actual stars. Another aspect of the film that caught my attention is the way boy scouts genuinely marveled at the sight of a dark sky filled with stars while camping in the countryside. This clearly points out the need to continually educate future generations, especially inner city kids, about astronomy and give them opportunities to experience all aspects of the great outdoors, including dark skies.
While The City Dark effectively informs viewers about light pollution and its impacts, it does not say much about what can be done to address the problem, especially in urban areas. Although Cheney tells us about a small town that passed an ordinance to preserve its dark skies, this example is not that helpful or relevant for big cities like New York City, Los Angeles, or Chicago. Curiously, the film also makes no reference to the IDA, which is commonly recognized as the authority on light pollution. Founded in 1988, the IDA is the first organization to call attention to the hazards of light pollution and promotes the idea of only lighting what we need, when we need it. The IDA works with planners, legislators, manufacturers, and citizens to develop energy efficient options that direct the light to where it is needed, not uselessly up into the sky. The IDA has even prepared a Model Lighting Ordinance which is a guide for environmentally responsible outdoor lighting inNorth America and is designed to help municipalities develop outdoor lighting standards that reduce glare, light trespass, and sky glow.