Proud Organization Member of the
International Dark-Sky Association
Stars Up Lights Down
The Durham Region Astronomical Association
Light Pollution Abatement Committee
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Why is light pollution an issue?
Light pollution wastes significant amounts of energy, causes unnecessary greenhouse gas production, disrupts the physiology of all living things including humans to the point of compromising health, is a safety hazard, and a nuisance.
What does FCO mean?
Full cut-off, as in full cut-off light fixture or luminaire. If all the light emitted by such a fixture is directed 10 degrees below a horizontal plane through the bottom of the fixture, then the fixture is deemed FCO.
What is a full cut-off light fixture?
A full cut-off lighting fixture, when properly installed, ensures that all light emanating from such a fixture is prevented from being emitted above a horizontal plane.
What is light trespass?
Light which is emitted from light fixtures on a property that shines onto adjacent properties, and into windows, thereby creating a nuisance and removing the rights of the affected property owner (or tenant) to enjoy their living or working environment.
What is a luminaire?
A fancy term for a light fixture?
What is glare?
Glare is defined as the visual discomfort resulting from insufficiently shielded light sources in the field of view. One should "see the effect, not the light source" - see what is being lighted, not the light (bulb).
What is sky glow?
The cumulative effect of letting light from a city, town, or other populous area escape above a horizontal plane and scattering off of atmospheric moisture and particles. This creates a a glow that masks the stars from view.
How much energy is wasted each year by letting light shine up?
It has been estimated that $2 billion in North America alone is wasted each year in letting light shine up into the sky. That works out to about $3.5 million in Durham Region every year. Approximately 50% of that light is from poorly designed street lights. That means $1.75 million in municipal tax dollars is spent on wasted energy for wasted light - every year. And that is only considering the light that shines up. Add to that the wasted light that spills (trespasses) into areas where it is not needed or wanted, and the numbers become even more staggering.
What percentage of greenhouse gas is contributed by lighting?
About 2.4% of personal lighting contributes to greenhouse gas. Lighting for street lights, and for commercial, industrial, and institutional uses would increase that percentage. Some of this lighting is outdoor lighting that is wasted by letting light shine up into the sky or into areas where it doesn’t belong, like in your bedroom window (or from you into your neighbour’s window) or into natural areas where it disrupts nocturnal wildlife and plants. It may not seem like much, but consider that 0.3% of greenhouse gas emissions comes from all the space cooling (air conditioning) used in just our homes. So wasteful outdoor lighting does contribute significantly more to greenhouse gas emissions than other things we take for granted.
Where can I buy good outdoor lighting fixtures?
The International Dark-Sky Association maintains a good list of lighting fixtures at their web site. Make sure you select a fixture that is defined as sharp full cut-off or full cut-off.