Twinkling little stars are no longer easy to see because light pollution is causing the night sky glow to brighter each year. Excessive poorly designed lighting that trespasses into the nocturnal world changes the predictable day/night cycle that life evolved in, consumes and wastes energy, contributes to the climate crisis, steals the beauty and wonder of the night sky, and damages biological/ecological rhythms and health. Nearly everything, from bacteria to humans, is impacted.
Wildlife species that work the dusk and dawn or graveyard shifts depend on uninterrupted darkness to provide exquisitely timed cues that direct communication, reproduction, protection, sleep, foraging behavior, and orientation. For long-distance migratory birds who travel at night during spring and fall using celestial navigation, artificial light kills an estimated one billion North American birds each year. Arthropods, like nocturnal moths—their fate seamlessly interconnected with other ecosystem members—perish rather than pollinating, breeding, and supplying bird food. And the seasonal cycle of plants, including trees—particularly those with the misfortune of being planted beneath streetlights or near other lighting—is threatened. Researchers believe that early bud break caused by incessant light will have a cascade effect on other organisms whose life cycles work in tandem with such plants, as well as the plants themselves.
Although nights are getting brighter every year with increased development, it is reversible. Many organizations work to preserve and protect the night skies, including Audubon of Portland’s “Lights Out” campaign. While it will take urban planners, designers, and elected local officials to create standards that minimize light pollution, we can each do our part with minimal effort:
Switch it off: Turn off unnecessary outdoor lights or, better yet, install motion-sensors designed to turn on only when needed and turn off after a short period of time.
Shield it: Use fixtures that aim light downward and are shielded to prevent glare and trespass on habitat and neighbors. Those with a solid cap above the bulb that prevents light from scattering are best; shades can be purchased to fit existing fixtures.
Warm it up: Select warm LEDs (under a 3,000 Kelvin rating) that supply only the amount of light necessary. Those that emit short blue wavelengths are brighter, scatter light more, and are worse for wildlife.
Keep light indoors: Close draperies, especially during peak migration seasons (April through June and August through November).
Request streetlight shields: PBOT will install shields or re-angle lights when necessary (www.portlandoregon.gov/transportation/article/672942).
Buck the trend of landscape lighting: Most “decorative” outdoor landscape lighting is pointless, wasteful, and detrimental to wildlife, particularly when lights point upwards.
Safety concerns? Most home burglaries occur in broad daylight, not at night, and excessive lighting does not lessen crime. Studies show that bright lights can make victims and property easier to see, as well as create much greater contrast and excessive glare, which increase the deep shadows that may actually assist crime and vandalism. To improve security, use motion sensors to surprise intruders.
Editor’s note: A Beaumont-Wilshire resident, Eileen is an ecological landscape designer and author of Real Gardens Grow Natives: Design, Plant, & Enjoy a Healthy Northwest Garden.