Editorial: Start at home to protect the dark

  • In a presentation about light pollution for a Western Mass Green Consortium “Green Night” event, Smith College astronomy professor James Lowenthal demonstrated the glare and waste caused by undirected outdoor lighting. For the Recorder/Andrea Bugbee

Published: 6/25/2019 8:11:14 PM

Two things we need to know about outdoor lighting: First, “warm” light is preferable to “blue (or day-)” light, and, secondly, directed light is preferable to undirected light. These lessons come courtesy of Smith College astronomy professor James Lowenthal, according to reporting by staff writers Greta Jochem and Melina Bourdeau, and by Andrea Bugbee in a recent issue of Going Green, a quarterly publication of the Greenfield Recorder.

Lowenthal is president of the Massachusetts chapter of the International Dark Sky Association, a nonprofit dedicated to curbing light pollution worldwide. Astronomers like Lowenthal lament the loss of the Milky Way to viewers of the night sky, but it’s not just of academic concern. Lowenthal said biological beings (including people) depend on a 24-hour cycle of light and dark for crucial functions such as sleep, breeding, navigation and avoiding predators. Insects, which are a food source to other animals and can act as pollinators for plants, are fatally drawn to bright lights. Birds and animals that navigate by moonlight are disoriented by bright outdoor lighting and the massive “skyglow” emitted by cities.

Skyglow also obscures the stars.

“This is a tragic loss,” Lowenthal said. “It’s a theft of nature.”

Modern LED lights come in a range on the Kelvin scale from “warm” (2,700) to “blue” or daylight (6,500). Blue light mimics light from the sun. When the sun goes away, our bodies naturally produce the sleep hormone, melatonin. Blue light at night deceives our bodies into thinking it’s still daylight. Studies have linked prolonged blue light exposure to obesity, diabetes, disruption of sleep cycles and some hormonally-related cancers.

The solution, Lowenthal says, is warm, directed lighting and progress toward these goals is being sought on local and state levels.

In Greenfield, efforts have been made to limit light pollution using Green Communities grant funding. LED lights in the neutral to warm range of 3,000 Kelvin have been installed in parking lots, schools and streets, which not only helped to reduce the city’s electric bill by 80 percent, but also helped reduce light pollution.

“That’s because we directed light only to go to the center of the road and sidewalks using the patterns for optimum safety,” according to Greenfield Director of Energy and Sustainability Carole Collins.

Statewide, legislation that aims to lessen light pollution has been filed and is co-signed by Rep. Lindsay Sabadosa, D-Northampton, Sen. Jo Comerford, D-Northampton, and Sen. Adam Hinds, D-Pittsfield. The act calls for any outdoor lighting paid for by state or municipal funds be under specific limits for brightness and blueness, and that new roadway and parking lot lights are shielded.

Local planning boards can introduce bylaws that specify outdoor lighting standards in their towns.

Here’s what homeowners can do to optimize their outdoor lighting:

1. Choose LED bulbs that burn at 2,700 to 3,000 Kelvin; these emit the least amount of blue light.

2. Use bulbs that are no brighter than you need.

3. Install timers and motion sensors whenever possible.

4. Choose fixtures with lids and shields that direct light downward rather than letting it flood an entire area.

“Start with your own house. Start with your neighbors. Start with your own communities and city councilors,” Lowenthal said. He regularly approaches businesses with bad lighting and offers to correct their fixture angles for a darker sky. “Offer to show up with your ladder.”

That’s what he does.

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