The Dark Side Of Light

As our cities grow (and grow), people must travel further afield to gaze upon a starry sky. But this is more than an inconvenience. New research reveals how light pollution hurts plants, animals and even human health

By Shannon Wilmot

On a clear night on Ontario’s Manitoulin Island, you can crane your head back and gaze upon a sky crowded with stars and other celestial wonders. You can see the Andromeda galaxy – the closest to ours at a mere two million light years away – with the naked eye. “It’s phenomenal,” says resident Rita Gordon, who has lived on the island since 1990 and is a founding president of the Manitoulin Island Dark Sky Association. “The galaxy has billions of stars and is one of the most faraway objects that can be seen without a telescope.” At different times of the year, the Orion constellation, the Summer Triangle, which includes the stars Deneb, Altair and Vega, and even a couple of nebulas (interstellar clouds of dust and gas where new stars may form) also light up the night. The Seven Sisters, or Pleiades, a cluster of stars resembling a mini-dipper, glow in the night.

Seen from the island on a cloudless night, the Milky Way slings across a sky that is packed with pricks of light. “We had an astronomy professor come up from Ohio and he was just flabbergasted that the Milky Way created such intense light,” says Gordon. “You just don’t see that anymore.”

In 2001, the Monthly Notices of the Royal Astronomical Society published the first world atlas demonstrating the pervasiveness of artificial light in the night sky. The atlas used satellite data, along with models of how light scatters in the atmosphere, to show the global impact of artificial lights. According to the findings in the atlas, approximately one-fifth of the world’s population, primarily people living in the United States and Europe, can no longer see the Milky Way without a telescope or binoculars. Many Ontarians, in fact, cannot simply turn their head upward and take a look at this spectacular galaxy. Manitoulin Island is special because it is free of light pollution. Bylaws passed by several of the island’s townships and First Nations ensure that outdoor lighting is shielded, architectural or decorative lighting is turned off at night and advertising signs are lit from the top rather than the bottom.

The Manitoulin Island Dark Sky Association had lobbied hard for these bylaws, explains Gordon. She and her husband operate Gordon’s Park, an eco-resort that includes a four-hectare area the family designated as a dark-sky preserve, dedicated to the appreciation of night and to various astronomy activities that include guest speakers and summer Astronomy Nights. Every Thursday at 9:00 p.m. throughout July and August, dozens of visitors learn about the night sky and observe the heavens using the park’s Dobsonian telescope and wide-angle binoculars. The annual Perseid meteor shower in August is especially popular. According to Gordon, last summer’s Perseids, which occurred, ideally, during the new moon, delivered as many as 60 to 80 meteors an hour. “The most vivid description I can think of is that it looks like the many spots on a peacock’s feathers moving across the sky,” explains Gordon. “I can’t wipe that vision from my mind. It’s incredible.”

Manitoulin is not the only place in Ontario to enact light pollution bylaws, nor is it the only place to have designated dark-sky areas. In 1995, Richmond Hill, just north of Toronto, became the first municipality in Canada to pass a light pollution bylaw. The bylaw regulates the installation, illumination levels, hours of operation and replacement of lighting fixtures in both commercial and residential areas. In 1999, more than 1,900 hectares in the Muskoka area became the Torrance Barrens Dark Sky Reserve, the first designated dark-sky area in Canada, recognized by the Royal Astronomical Society’s Light Pollution Abatement Program. More recently, the program recognized the conservation efforts of Point Pelee National Park, in southwestern Ontario, with a dark-sky designation.

Yet despite these efforts, few of us can enjoy an unobstructed view of the sky at night. Light pollution, caused by unshielded, misdirected and overpowered lights, obscures our view, bathing many of Ontario’s cities and towns in the glow of an eerie perpetual twilight.

Simply put, light pollution is light that goes where it doesn’t belong – illumination from floodlights spilling into neighbouring yards, unshielded street lights casting light upwards and horizontally. Gas stations and mall parking lots are the most egregious light pollution offenders in the city. “You can practically do brain surgery under some gas-station canopies,” says Robert Dick, who manages the Light Pollution Abatement Program and teaches astronomy at Carleton University. Architectural, or decorative, lights that are set on the ground and pointed upwards to illuminate the front of a building or trees in a front yard are another big offender. But artificial light at night doesn’t just block the view. Researchers are beginning to discover its adverse environmental effects on wildlife as well as negative impacts on human health.

As dusk approaches, bird watchers and dog walkers trail out of the 75-hectare property of the David Dunlop Observatory in Richmond Hill, and a different type of naturalist takes their place. Amateur astronomers set up telescopes on the grass, while inside the white dome of the observatory, researchers peer deep into space using Canada’s largest telescope. When it was installed in 1935, the same year the observatory opened, the 1.88-metre, 23-tonne telescope was the second largest in the world.

For more than a decade, dark-sky enthusiasts and members of the North York Astronomical Association (NYAA) have also been making visits to Oak Heights, outside of Cobourg. The eight-hectare woodland site includes such amenities as a permanent observatory with a Ritchey- Chrétien telescope and a bunkhouse warmed with a propane heater. At the annual StarBQ each summer, some 40 association members enjoy the night sky, many of them camping out. NYAA president Malcolm Park says it’s not uncommon to be startled by the sound of beavers slapping their tails or to be serenaded at length by the nocturnal whippoorwill. But the real excitement takes place in the sky. At Oak Heights you can see the Milky Way stretch almost from horizon to horizon and easily lose count of the number of meteors seen during an intense shower.

For centuries, humankind has been dazzled by a twinkling sky. The stars have influenced our philosophies, literature, science and art. Sadly, the window into our own galaxy as seen from such places as Oak Heights and Manitoulin Island is closed to most Ontarians. Light pollution, however, is more than just an annoyance to astronomers. Clear, dark nights are crucial to our health, wildlife conservation and energy efficiency.

Studies have shown that excessive light at night can disrupt our circadian rhythm – the internal clock that evolved in response to the earth’s day-night cycle. This disruption can result in chronic illness, sleep disorders and even psychological problems. Studies done on nightshift workers have produced startling results. The Journal of the National Cancer Institute published a study in 2001, which found that women working the graveyard shift were up to 60 percent more likely to develop breast cancer. The U.S. study involved hundreds of women in whom breast cancer had been diagnosed and examined their exposure to light at night during the 10 years prior to diagnosis. Additional research is uncovering more findings that support the link between light at night and breast cancer rates.

Like humans, many animals and plants are dependent on the earth’s day-night cycle. The proliferation of unwanted light has been linked to all sorts of unnatural occurrences. Plants and trees may retain their leaves longer into the season than they should. Brightly lit roadways, poorly designed developments, growing urban centres and even misdirected outdoor lighting on farms can all cause alterations in the foraging habits of nocturnal animals. Zooplankton normally feed on algae at night, but a study conducted in 1997 at a lake outside Boston, Massachusetts, found that urban light pollution reduced feeding behaviour. Algae can build up, which, in turn, has a potentially adverse effect on water quality. Many herbivores, explains Dick, use the cover of darkness as protection from predators. If a new road or other brightly lit development is introduced into an animal’s habitat, the animal may be repelled by the light and move elsewhere.

In a 1996 study on the disruption of the predator-prey relationship in British Columbia, seals were found to be using the glare of artificial lights to seek out their prey, juvenile salmonids. Simply turning out the lights on a nearby bridge immediately provided the salmonids with better protection from harbour seals.

Excessive light has been found to affect animal foraging and hunting habits, as well as communication and reproduction. In Florida, light pollution is recognized as a major threat to sea turtles and their hatchlings. Hatchlings emerge from their nests at night and use the glow of the moon and stars reflecting off the water to find their way from the beach to the ocean. Typically, the turtles move towards this light and away from the dark silhouettes of dunes, vegetation and other beachfront landscapes. Researchers noticed that coastal lighting from homes and other developments disoriented the hatchlings, causing them to lose their way and become more susceptible to predators, resulting in thousands of deaths each year. Excessive light also caused female turtles to avoid nesting sites that were otherwise ideal.

In cities, the perpetual light of office towers and other skyscrapers kills millions of migrating birds a year. The Fatal Light Awareness Program (FLAP) is a Toronto conservation group that works to protect birds by encouraging Torontonians to turn out their lights at night (see “Flick the switch,” page 29). Indeed, more birds die each year in North America from collisions with buildings than succumbed to the Exxon Valdez oil spill in 1989, when 41 million litres of oil poured into Prince William Sound, Alaska, killing thousands of seabirds.

The ultimate dark-sky villain is sky glow. This is the dome of light caused by architectural lighting, gas-station canopies, street lights and parking lot and retail lighting, and other misdirected and overpowered lights that extend over the province’s urban areas; the night is never truly dark. As urban sprawl grows, so, too, do these domes of light, intruding into Ontario’s wilderness. In a city or town, the severity of sky glow is most clearly evidenced by how few stars are visible. Misdirected light scattering off dust and other particles in the air causes sky glow. Air pollution in cities vastly increases the amount of particulate matter, thus exacerbating the effect. “As a result, hardly anyone looks up anymore,” says University of Toronto professor and astronomer Tom Bolton.

In 1972, Bolton discovered the first black hole using The milky way lights up the sky naturally photos: Christian Autotte photo: courtesy of flap the David Dunlop Observatory’s telescope. But among dark-sky enthusiasts he is celebrated more for having spent two decades fighting for Richmond Hill’s landmark light pollution bylaw. Despite the University of Toronto’s announcement last September of plans to sell the observatory and its land – citing light pollution as part of the reason – Bolton says that “light pollution has had no direct negative effect on observing at the observatory since 1971.” Currently, the Richmond Hill Naturalists, an Ontario Nature member group, is spearheading the Save the David Dunlop campaign, raising money to save both the observatory, including the telescope, and its forest-covered lands. The group hopes to raise $60,000 to pay legal fees as it pursues protective measures for the land. The group is also circulating petitions and, through events and weekly guided walks of the site, highlighting the importance of the property. “We have a lot of people who are very concerned about its future,” says Marianne Yake, president of the Richmond Hill Naturalists. “It is the largest green space in the southern York region left undeveloped.”

Fighting light pollution has united naturalist and astronomy clubs. In fact, the Richmond Hill Naturalists was formed in 1955 by two astronomers; one was Helen Hogg, well-known for her efforts in educating the public on the science and wonders of the heavens, which included an astronomy series on TVOntario and a column that ran in the Toronto Star for 30 years. Hogg researched globular clusters – or stars drawn tightly together by vast amounts of gravity – at the David Dunlop Observatory. Yake explains the close relationship between naturalists and astronomers as a recognition of the cohesiveness between the stars above and the earth below. “The more light we have in our communities, the more it creates problems for us seeing nature in its true beauty.”

“For me,” adds Gordon, “it is comparable to polluted lakes and forests – it’s another avenue of nature that needs to be maintained and protected.”

Advocates agree that to convince more municipalities to take the issue of light pollution seriously, it is important to emphasize the cost-effectiveness associated with protection initiatives, due to increased energy efficiencies. Says Bolton, “We do not need the level of lighting currently being used. It’s just a terrible waste of energy and money.” The City of Calgary retrofitted some 40,000 of its street lights with full cut-off lighting – fixtures that by design ensure that no light is misdirected upwards or horizontally – for an expected annual energy savings of $2 million and as much as 16,000 tonnes of carbon dioxide saved each year. Dick says that these days, municipalities are more responsive than ever to the light pollution grievances of its citizens. “Now is the perfect time for us to approach government and get change started. Street lights last for about 30 years. So what we do now is for our children and our children’s children.”

Dick’s group worked with Parks Canada to help develop best practices to protect the nighttime environment in federal parks. The group is now looking into developing urban star parks. He points out that some parks lock their entrances at night. A dark-sky preserve requires 24-hour access to a park, allowing visitors to enjoy the natural environments of both day and night. Dick envisions kiosks with brochures on star-viewing locations and astronomy, as well as interpretative, nocturnal walks with a guided tour of the stars. It may seem redundant to designate as dark-sky preserves protected areas that are already dark, but Gordon, for one, believes that sanctuaries like Gordon’s Park are vital to introducing many of Ontario’s children to what the night sky looks like without artificial light. “I think that as the viewing opportunities diminish in the places close to urban areas, the appreciation for the dark skies will get more sincere and the desire to see them will grow.”

Raising awareness is key. At its annual general meeting last June, Ontario Nature put forward a resolution recognizing that dark skies are required to protect the province’s animals, plants and general population from the adverse effects of light pollution. The resolution set forward measures the organization believes should be adopted by government, such as retrofitting street lights, changes to the Ontario Building Code and mandatory energy conservation plans for new buildings.

Even at Oak Heights, Park says the NYAA cannot fully escape light pollution – three light domes are visible. Not many places are left in southern Ontario where you can escape the light, he says. But Park does know of one out-of-the-way location just north of Bon Echo Provincial Park in southeastern Ontario, where the whole sky is pitch black. That place is affectionately nicknamed Nirvana.