June 10, 2019

How light pollution affects our relationship with the sky

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I often find myself thinking about stargazing and light pollution. Not in an all-consuming way, of course, but in more of an “Oh! Wow, the stars are really bright in this neighbourhood” sort of way.

 

When I first got my driver’s license, I lived 15 minutes outside of a small prairie city where I attended high school. Like many 16-year-olds, I didn’t rush home after the last bell. Instead, I drove back after dark, watching how the orange glow of the city would fade behind me, and then when I stepped out of the car at home, a totally different sky than the one I left would be there to greet me. Now, living in the middle of a sprawling metropolis, I can only see a few stars from my backyard, and nothing close to that black, deep and impressive star-filled sky of my family’s home in the country.

It’s important to note, however, that the sky I described in the country can also be seen in our urban communities. We just need to change the amount of artificial light and the method of how we use it at night. As a designer, I notice more and more “dark sky compliant” lighting products and local requirements for these types of lighting designs.

The International Dark-Sky Association (IDA) is responsible for this movement. They advocate “to preserve and protect the nighttime environment and our heritage of dark skies through environmentally responsible outdoor lighting”. The IDA defines light pollution as “the inappropriate use of artificial light”, outlining appropriate light use as “only be on when needed, only light the area that needs it, be no brighter than necessary, minimize blue light emissions, and be fully shielded (pointing downward)”.

This issue is much larger than just not being able to see the starry sky. Light pollution also negatively impacts the environment, local ecology, human safety and health. Below is a very simplified list of the negative impacts of light pollution as described by the IDA:

  • Environment: inefficient use of light wastes energy, resources and money.
  • Ecology: plants and animals “depend on Earth’s daily cycle of light and dark rhythm to govern life-sustaining behaviours such as reproduction, nourishment, sleep and protection from predators” and artificial light disrupts these behaviours.
  • Health: just like plants and animals, humans adhere to a circadian rhythm that is interrupted by artificial light. There is a long list of health impacts including “increasing risks for obesity, depression, sleep disorders, diabetes, breast cancer and more”.
  • Safety: There is no evidence that brighter is actually safer. In fact, areas that are too bright or have poorly shielded lights have been known to be more dangerous as the glare “decreases vision by reducing contrast. This limits our ability to see potential dangers at night. Ageing eyes are especially affected”.

As I was researching this topic, many sources relied on the anecdote of the power outage after an earthquake in Los Angeles in 1994 to convey just how disconnected we have become from the sky. A version of the story was published in the National Geographic this past April: “Startled awake, some residents who had stumbled outside called various emergency centres and a local observatory to report a mysterious cloud overhead. That weird object turned out to be the Milky Way, our home galaxy, which had long been obscured from view by the city’s lights”.

Humans have only had artificial light technology for less than 150 years, and yet the relationship of city dwellers and the sky is almost nonexistent. So, what are city dwellers missing in terms of happiness and healthiness when it comes to gazing at the stars?

According to Dacher Keltner, a psychologist at the University of California, Berkeley, “the star-splashed canvas rotating overhead on clear nights elicits a sense of wonder and awe that may translate into positive human behaviours”. He writes, “Philosophers have written about how a big beautiful sky makes you feel like you’re part of something big like it’s sacred like it’s purposeful. [However], by contrast, a smoggy sky that is closing in on you or a night sky that’s filled with pollution kind of weighs heavily on your consciousness.” In fact, studies support this assessment, finding that participants who had recently experienced that “sensation scored higher on evaluations of scientific reasoning and were kinder, more altruistic and less materialistic”.

Many cities have a few pages in their bylaws that discuss exterior lighting, mainly for commercial and industrial zoned areas that are in proximity to residential areas. However, the language is more geared towards having different land uses next to one another and less about reducing light pollution. On the other hand, some communities take the fight against light pollution very seriously, which the IDA has designated as Dark Sky Places.

In Canada, the only place with this designation is Bon Accord, a town 40 kilometres north of Edmonton. The city’s mayor told the CBC at the launch that it’s a “new beginning” for the identity of the town. Bon Accord had a transition period to retrofit their existing infrastructure, but some new developments have been built with the dark sky principals at their core from the concept design. One such community is called Summit Sky Ranch—a new 240 single-family home development just outside of Denver that uses the dark-sky focus for advertising a different way of life. Moreover, it seems to contribute to the sale of their high-end homes as well. 

Light pollution is a quiet but persistent problem that we all contribute to and in turn, have the power to change. By simply changing how and when we light our exterior environments, we can use less energy, improve ecological and human health AND be greeted by a spectacular starry sky every night. Now, doesn’t that sound dreamy?