Less than 100 years ago, a person could look up into the night sky and see thousands of bright stars. Today, widespread and ever-increasing artificial light makes this impossible in many places across the globe. This excessive use of artificial light is light pollution. Just as with pollution of our water and air, light pollution can have serious environmental consequences for humans, wildlife and even our climate.
Plants and animals depend on the Earth’s daily cycle of light and dark. For animals, this is important for life-sustaining behaviors such as reproduction, sleep, and protection from predators. There is scientific evidence that artificial light can have deadly effects on many creatures from hummingbirds to wallabies. Birds that migrate at night are navigating by moonlight and starlight. Each year, artificial light is responsible for millions of deadly bird collisions with buildings and towers. Monarch butterflies also rely on darkness. This is when they process proteins that are key to their internal compass that points the way towards their wintering grounds and return. Researchers found that butterflies roosting near porch or streetlights are disoriented the next day. Amphibians like frogs and toads are nighttime breeders so lights interfere with reproduction thus reducing populations. Sea turtle hatchlings must get from the beach to the sea. They can only find their way by detecting the bright horizon over the ocean. Artificial lights draw them away from the water and each year millions die in this way.
This time of year, we are hopeful for witnessing fireflies blinking along woodland edges and in moist meadows as we did in our youth. But more and more fireflies are disappearing. Most researchers believe loss of habitat due to increased housing and commercial development is a main factor. Open fields and forests are being destroyed. Increased activity along waterways is also detrimental to these valuable critters whose larvae are hugely beneficial for controlling snails and slugs. There is no question pesticides are having a detrimental effect on all invertebrate species, especially fireflies. Mosquito spraying, for example, is totally ineffective for mosquito control but does kill fireflies and many other beneficial insects.
And, it should come to no surprise that artificial light is extremely harmful to fireflies who need to communicate with one another to find mates. Lights from homes, cars, businesses and streetlights, make it difficult for fireflies to signal each other, resulting in fewer larvae born the following season.
Much of our outdoor night lighting is inefficient and, in many cases, unnecessary. Artificial lighting is often overly bright and improperly shielded. Light spills into the night sky instead of focusing on objects for which the light is intended. According to a 2016 study, 80% of the world’s population lives under sky glow which is an artificial brightening of the sky. These polluted skies are of world-wide concern.
But unlike other forms of pollution, light pollution can be reversible if we take the appropriate steps. Each one of us can make a difference. The International Dark-Sky Association indicates Five Lighting Principles for Responsible Outdoor Lighting.
4. Use light only when it is necessary. Timers or motion detectors ensure light is available as needed.
Lights Out Connecticut, Lightsoutct.org, also suggests keeping blinds and shades drawn to keep light inside, especially on upper floors and when working at night.
Good news! On June 27th, Governor Lamont signed Substitute House Bill No. 6607, Public Act No. 23-143 – An Act Concerning the Nighttime Lighting of State-owned Buildings at Certain Times for the Protection of Birds – requiring state-owned and leased buildings to turn off nonessential outdoor lighting during peak avian migration periods in order to assist in preventing birds from flying into the sides of such buildings. Nonessential outdoor lighting shall be turned off between the hours of eleven o’clock p.m. and six o’clock a.m.
There’s much more to do. It is important for our Garden Clubs to continue our efforts as leaders in our communities on all environmental and conservation issues. Members are highly qualified with vast experience as gardeners, master gardeners, birders, activists and educators. The public isn’t always aware of the negative impacts of practices such as excessive use of artificial lights. As ambassadors, we can help bring awareness to this growing problem and inspire more people to take necessary steps to protect our natural night sky that will benefit us and the wildlife with whom we share this world. For more information, visit www.DarkSky.org