A client recently asked me if GreenWeaver installs outdoor lighting. I always respond to this question with reservation. As an environmentally responsible landscape company, how do we justify adding services that require electricity, have the potential to damage the night-time ecology, and can even harm human health? The answer is with thoughtful lighting design, of course.
Problems with Nighttime Lighting
Most people understand the term light pollution when applied to astronomy or irritating lights shining in bedroom windows at night. There are however, much greater problems associated with light pollution.
Outdoor Lighting and Ecology
When most of us are crawling into bed at night, there is another complex ecology that is just beginning to awaken. Flowers in need of pollination by moths, fireflies searching for each other by using their own illumination, owls whose predatory advantage depends on darkness, and even baby sea turtles searching for their way to the sea all depend upon dark nights.
Studies show that light pollution has harmful effects on nighttime ecology in ways that we are only beginning to understand. For more information please visit http://darksky.org/light-pollution/wildlife/
Nighttime Lighting and Human Health
Nighttime lighting disrupts our circadian rhythm which keeps us awake during the day and allows us to sleep at night. “Disruption of the circadian clock is linked to several medical disorders in humans, including depression, insomnia, cardiovascular disease, and cancer…” says Ron Chepesiuk in his article Missing the dark: health effects of light pollution.
And according to Bill Blakemore in his article Scientists Say Darkness Benefits Health “Scientists have now discovered that only when it’s really dark can your body produce the hormone called melatonin. Melatonin fights diseases, including breast and prostate cancer.”
The evidence is compelling enough that the World Health Organization now considers Artificial Light at Night a probable carcinogen.
Lighting to Deter Crime
People often believe outdoor lighting reduces crime, but statistics are inconclusive in this regard. In some cases lighting may be beneficial, but poor nighttime lighting is actually dangerous if it causes glare, or provides dark shadows where criminals can hide. And where no one is watching, lighting allows them to case targeted areas and to see what they are doing. Even graffiti is reduced in the dark because it’s usually lit walls that attract the spray-can vandals.
Police report that sometimes darkness is safer. If neighbors notice unusual lights at night, they are more likely to call the police.
Essentially, lighting for safety is not as simple as it seems.
Tasteful Outdoor Lighting
Although tastes vary, apply these general rules when designing outdoor lighting.
Less is More
Assuming you do not want your nighttime property to look like it does at high noon, the first step is to determine what you want to illuminate.
Use different levels of lighting for different purposes. Use low lights for soft mood lighting or path lighting. Brighter lights direct attention to accents or areas of importance.
Dimmers are also nice options. Softly illuminate outdoor seating areas during entertaining, and then turn up the light during cleanup.
Lighting is measured on the Kelvin temperature color scale. Choose warm colors in the 2000-3000K range for the most relaxing and inviting spaces and avoid blues which appear cold and unnatural.
Use timers carefully! They are frequently set and then forgotten resulting in unnecessary waste and expense. We had one client who routinely went to bed around 10PM. Her installer set her timer to turn lights off at 2AM. That is 4 hours of unnecessary lighting every night!
Smart Outdoor Lighting
Given all of the problems associated with outdoor lighting, what can we do?
First, choose your lighting based on type of use, frequency, and affect on nighttime ecology. Consider the lighting types below listed in order of environmental impact.
Types of Lighting
- Luminaries and Candles
- Traditional Low-Voltage
Lower impact lighting tends to be softer and less expensive. Avoid lighting types at the bottom of the list.
Tips for Smart Outdoor Lighting
According to the International Dark Sky Association, responsible lighting should:
- Only be on when needed
- Only light the area that needs it
- Be no brighter than necessary
- Minimize blue light emissions
- Be fully shielded (pointing downward)
Of course, we will never eliminate the need for outdoor lighting, nor should we try. Outdoor lighting can be magical. It can set amood from festive to romantic, celebratory to intimate. It can be welcoming and inviting.
So we at GreenWeaver recommend tasteful and responsible outdoor lighting to celebrate the night. And when the celebration is over, we recommend turning off the lights, so others can enjoy the darkness.
For more information consider:
The End of Night: Searching for Natural Darkness in an Age of Artificial Light
by Paul Bogard , Back Bay Books; Reprint edition (July 22, 2014)