This Earth Hour, Think Before Turning the Lights Back On
I was 22 when I saw the Big Dipper for the first time. An embarrassing admission, but true. For someone who grew up in the suburbs, and not even in the heart of the city, the night sky was like a somewhat familiar acquaintance. What was immediately familiar, though, was clutter, trespass, and glare – the unmistakable trademarks of light pollution. As Earth Hour wraps up on March 27th at 9:30 PM, we should think for a moment before turning the lights back on. This international event draws attention to the importance of addressing climate change and our current energy use, but it also reminds us in a very visual way of the enormous impact we have on the planet with the design of our urban spaces.
Our nighttime urban environment is cluttered with light coming from a confusing number of sources. Light trespasses into areas where it is unnecessary or excessive and overwhelms others with glare. The overall effect is urban sky glow, where the night sky disappears in a wash of over-illumination. Beyond the fact that finding dark skies now requires an increasingly longer trek, we’re wasting unbelievable amounts of energy and money in shining light upwards – estimated at billions in North America. The cumulative cost of wasted energy hasn’t yet been added up for Canadian cities, but this deserves attention, especially in a city like Vancouver that prides itself on a progressive approach to sustainability.
Studies in recent years, notably in Calgary and the UK, also don’t support the link between increased lighting and safety. Excess light attracts rather than discourages crime – as it turns out, criminals, like everyone else, need to see what they’re doing. Although we might feel safer, bright, ceaseless light loses its surveillance function because we’re so used to it. Motion-activated lights, with the proper sensitivity settings, are much more effective at alerting us to break-ins or vandalism. Another effect of excessive lighting is that it confuses our circadian cycle, and research is increasingly indicating that higher rates of breast cancer are linked to light pollution.
Vancouver needs to follow the lead of cities like Calgary and Tucson in adopting more comprehensive light pollution bylaws. Right now Vancouver lacks an official light pollution plan, and there are currently no city-wide legislation or bylaws in place. Part of why light pollution has been skirted over as an issue is because of a lack of awareness. It may be that the very fact that light pollution is everywhere is what makes it so hard to notice.
In terms of lighting, the approach needs to be smarter rather than darker. Addressing light pollution doesn’t mean creating darker streets, it means carefully considering where we choose to direct light. Full cut-off lighting, where the fixture is designed to shine light downwards, improves visibility by minimizing the contrast between lit and unlit areas. Conventional streetlights and spotlights create a cascade of light that’s sharply separated from darker areas, and this intense contrast makes it a lot tougher to see anything that isn’t directly under the fixture.
Full cut-off fixtures also save energy by directing light at what we need to see, which is really closer to the ground. We need to keep in mind why we need light in our urban spaces. Light helps define and bring into focus the features we need to safely navigate the city, such as our roads, sidewalks, bicycle paths, bus stops, and doorways. In addition to installing more efficient fixtures, being smarter about our energy use requires us to fundamentally change the design of our lighting, and to resist treating light as an inexhaustible resource.
I fell in love with astronomy as a kid, and got to take my first astronomy class in university (incidentally where I first learned how to identify the Big Dipper.) Beyond bringing attention to the scope of climate change and the impacts of our lifestyle, Earth Hour is really about bringing attention to the earth. In 1968, Apollo astronaut William Anders captured the image of a crescent earth rising above the moon’s horizon, and it has since been described as “the most influential environmental photograph ever taken.” It’s one of my favourite pictures, and I think one reason why it’s so compelling is it starkly reminds us that that’s it – we really have nowhere else to go. By losing our night sky we are gradually losing our window into the universe, and dimming the realization that our planet can’t infinitely absorb our mistakes.