“What do we lose when we lose the night?” That’s the fundamental question The City Dark explores, a documentary that looks at the impact of ever-increasing light pollution from city glow. The documentary is loaded with talking heads, from astronomers and cosmologists (including the awesome Neil deGrasse Tyson, naturally) to biologists and ornithologists, from historians and criminologists to lighting designers and even the owner of a light bulb store. Through a series of chapters, the documentary looks at the impact of the fact that two-thirds of the human population live under skies polluted by light and what this growing glow means for our pale blue dot.
The obvious impact of the increasing light pollution, caused by our city lights reflecting off of particulates in the atmosphere, is on our ability to view the night sky. As a longtime New York astronomer tells us, folks in New York City have been able to see the Milky Way exactly twice over the past several decades, when there were two city-wide blackouts. Similarly, Tyson notes that thanks to the conditioning that comes with living under a city’s glow and often only getting to see a beautiful night sky in a planetarium, on the rare occasion when he gets to be on a secluded mountaintop looking at the beautifully rich and filled sky, he has the “sickeningly urban” thought that it “reminds me of the Hayden Planetarium.” The lack of true nighttime visibility severely impacts scientists’ ability to study the universe, which harms the general process of science and inquiry. Astronomers try to combat this as best as they can, such as by building telescopes on Hawaiian mountaintops above the clouds or creating dark villages in the middle of nowhere, but they face an uphill battle.
The film goes on to show how it’s not just human inquiry that is harmed by the loss of the night sky. In the most interesting parts of the film, we see how human health itself may be affected, and how animals are also finding their lives complicated by the increasing of light pollution. Apparently, several years ago the World Health Organization declared that working night shifts, because of the disruption to a person’s circadian rhythm, is a probably carcinogen. This was fascinating news to me, and The City Dark wonders about the relationship between this and increase in light pollution, since light at night leads to a suppression of melatonin, which directly affects your circadian rhythm. As for the impact on animals, The City Dark shows the suffering light pollution has caused to certain migrating birds that have evolved to use the stars as their map, or hatchling sea turtles whose evolutionary preconditioning has told them that the bright horizon leads to the sea (where it now leads to Miami). Because the film covers so many topics, it’s not able to hit certain things in as much depth as one might like, and these are the sections that particularly suffer. What is included is good, I just found myself curious to hear more, particularly about how animal life is suffering as a result of our never-ending need for more light.
The doc also looks a little at why humanity has this needs to add more light, and how some folks are trying to meet these needs while also minimizing the impact on the sky and the environment. Ultimately, The City Dark tries to cover a lot of ground and winds up suffering as a result, feeling a bit underdeveloped. The problem that The City Dark tries to address is an important one, and the film does a decent job of exploring this problem, but the breadth of topics covered, which should make the doc feel rich, actually winds up making it rather flat. It’s not a bad documentary, it’s just that it would probably work better as a documentary series, with four or five longer documentary shorts. And to my disappointment and dismay, no Strangers ever show up in the documentary.
The City Dark had its world premiere at South By Southwest 2011.