CBC Light Pollution

Light pollution Last Updated November 2, 2007 By Georgie Binks http://www.cbc.ca/news/background/space/light-pollution.html It may not make any difference who you are when you wish upon a star, but it sure matters where you are these days. Light pollution is making it increasingly difficult to wish on the first star of the evening, says International Dark-Sky Association executive director David Crawford. "The vast majority of people live in cities and don't see the stars anymore," he says. "There has been a huge increase in light pollution in the past 50 years. It's bad for amateur astronomers and it's worse for professional observatories. It's also bad for our children because they're not seeing the universe they live in. All they're seeing is street lights." Some observatories are finding encroaching light pollution is greatly affecting their ability to view the stars. (Mark Rightmire/AP) The International Dark-Sky Association wants to stop the adverse effects of light pollution on skies. It monitors light pollution levels all over the world. Recently, the association awarded its first International Dark Sky designation to an area in Quebec — the regional county municipalities of Granit and Haut-Saint-François along with the City of Sherbrooke. Dark Sky Reserve An International Dark Sky Reserve is defined as an area that possesses an exceptional or great quality of starry nighttime views, and a nighttime environment that is actively protected for its scientific or natural reasons. The peripheral area also has to meet criteria for sky quality and natural darkness. Canadian Dark Sky Preserves and Reserves Torrance Barrens Dark Sky Reserve, Ontario Point Pelee National Park and Dark Sky Preserve, Ontario Cypress Hills Dark Sky Preserve, Alberta/Saskatchewan Beaver Hills Dark Sky Preserve, Alberta Fraser Valley Dark Sky Preserve, British Columbia Chloé Legris, in charge of the light pollution abatement project at the Astrolab of Mont-Megantic, which sits in the heart of the International Dark Sky area, explains the hard work that earned the area the designation. "We had to enact some bylaws in the area. We replaced 2,500 lighting mercury vapour lamps in municipalities around the observatory with high-pressure sodium lamps. We changed the lighting fixtures so they don't throw off light or cause glare. We reduced light pollution, glare and energy consumption and will save about 1.5 million kilowatt hours per year." Legris says the area is classified as a class 3 on the Bortle scale. In 2001, American astronomer John Bortle devised his own measurement system for light pollution — the higher the number, the higher the nighttime light level. A Class 1 ranking is the darkest. Skies several hundred years ago would have gained that ranking. Most suburban cities are Class 5, 6 or 7. New York City tops the list as a Class 9. The dark side of light Light pollution is a problem for astronomers trying to watch the heavens. Some observatories are finding encroaching light pollution is greatly affecting their ability to view the stars as they once did. Light pollution was such a problem at the University of Toronto's Dunlap Observatory that it is being sold. When it first opened 72 years ago, farmers' fields surrounded it. Now there's adjacent housing and the light pollution from the surrounding area has limited what astronomers can see in the sky. Light pollution is actually causing many serious stargazers to visit Hawaii or Chile, where people can find the best viewing these days, Crawford says. But it's not just astronomers who are affected by the lack of darkness after the sun goes down. "People believe the more light they have, the better they're going to be. However, it adversely affects health, sleep, and causes people to be out of sync with nature. About a third of light pollution comes from street lights and parking lots, a third from commercial lighting and a third from residential," Crawford says. Light pollution also affects wildlife, notes Michael Mesure, executive director of the Fatal Light Awareness Program (FLAP). "There are more than 450 species of birds that migrate to the Ontario region," he says. "They migrate at night and any brightly lit structure attracts them to the urban environment. Unfortunately, because of that attraction, they collide with the structures." Light pollution information Edmonton Light Pollution Awareness Royal Astronomical Society of Canada Star Parties Fatal Light Awareness Program International Dark-Sky Association The Bortle Dark-Sky Scale FLAP has been running a program called Lights Out Toronto, encouraging people to minimize lighting at night. "One victory I consider huge is that the CN Tower used to use floodlighting, which killed a tremendous number of birds. Now they've introduced the LED lighting system and they've also agreed to turn their lights off during the migration season," Mesure says. The issue of light pollution is also drawing supporters because it's tied to potential energy savings. The City of Calgary, for example, recently cut its spending on electricity by more than $2 million a year by switching to full-cutoff, reduced-wattage street lights. Other Canadian cities are also being asked to turn off or tone down unnecessary lighting. Raising awareness The dark sky movement is being taken seriously south of the border, as well. Both San Francisco and Los Angeles participated in a Lights Out event between 8 p.m. and 9 p.m. on Oct. 20, 2007, to draw attention to how the night sky has changed as cities have expanded. Next year, Crawford hopes more cities will participate. To heighten awareness in Canada, the Royal Astronomical Society of Canada holds "star parties" billed as overnight adventures at suitable dark-sky sites. Participants get to meet other astronomers, compare notes on equipment, hear talks and — of course — stargaze. Most star parties are held in provincial parks. Toronto's star party is held in Algonquin Park, several hours away from the city, which shows just how far big-city folks have to travel to gawk at constellations. The next big job is teaching children about the importance of dark skies, say those trying to reduce light pollution. In January 2008, Alberta Parks will introduce a program to the province's elementary schools dubbed D.S.I.: Dark Sky Investigators. It includes a theatre performance, classroom study and a field trip concentrating on astronomy and the preservation of the nocturnal environment. These days, many people are thinking about energy conservation and reducing pollution. Crawford says each person can make a difference in cutting light pollution, too. "Don't have a light on if you don't need it, inside or out," Crawford says. "Don't overlight, don't have glare, and make sure to shine the light down, not sideways into somebody's eyes or up into the skies." There now — what was that wish?