Editor:

International Dark Sky Week 2022  is coming.  It begins on Earth Day, April 22, and ends with the new moon on April 30.  Astronomers, both professional and amateur, have long known that the time around the new moon is the best time for viewing stars and planets because that’s when the night sky is darkest.  

In recent times, it has been harder and harder for astronomers and others to find night skies dark enough to see the stars, let alone continue to explore the universe, even when there is a new moon. Greatly increased artificial light at night has obscured our view of the night sky. 

There is more at stake in reducing artificial light than exploring the universe, important as that is. In his book, The End of Night, Paul Bogard writes “In ways we have long understood, in others we are just beginning to understand, night’s natural darkness has always been invaluable to our health and the health of the natural world, and every living creature suffers from its loss.” 

We need electric light for human safety, comfort and health, but lighting up the night sky for amusement or displays should be kept to a minimum.          

It’s especially important that artificial light be kept to a minimum in our urban parks. At night, our city parks can be oases of dark in the otherwise unrelenting glare of electric light that engulfs most of our city. 

“… light pollution has a negative influence on a variety of animals and plants in a variety of ways. It has been shown to disorient animals. Light pollution affects mating, alters predator-prey behavior, confuses migration, and influences animal physiology. Effects have been observed over a full range of taxonomic groups, including birds, reptiles, mammals, amphibians, fishes, invertebrates, and plants” – Connie Walker, “A Silent Cry for Dark Skies“, The Universe in the Classroom 

California is the first U.S. state to have an official policy of conserving 30 percent of its lands and coastal waters by the year 2030.   One goal of the plan is to do this in a way that provides better access to nature for communities, especially urban areas. Viewing stars under natural nighttime skies and trying to minimize the effects of artificial lighting at night on the plants and animals with whom humans share our urban areas are both vital parts of access to nature.  

“While astronomers worldwide have been sounding the alarm about light pollution since the 1970s, ongoing scientific research has shown that artificial nighttime lighting is harmful to wildlife and human health. In Pittsburgh, that urban phenomenon is set to change thanks to a new ordinance that makes it the first major American city to adopt lighting standards addressing light pollution. The law requires all new construction and renovations of city-owned buildings [only] to comply with dark sky lighting principles, including replacing all the city’s street lights with fixtures that feature timers and dimmers, so they are only on when needed; are shielded, so light is directed at a specific area and is no brighter than necessary…” Christina Griffith, thephiladelphiacitizen.org  Dec. 14, 2021.

We’re not stuck with light pollution. We can make changes. If Pittsburgh can implement a Dark Skies ordinance, why not San Francisco?  It’s the environmentally responsible thing to do.  San Francisco can work with the International Dark-Sky Association (IDA), which has worked with various individual cities to assist in the kinds of lighting technology that would minimize light pollution. 

The cities of Alameda and Emeryville have passed dark sky ordinances. We need our Board of Supervisors to follow their lead and find ways to help create darker skies for San Francisco.  It’s good for the planet.

San Franciscans for Urban Nature (SFUN)

SFUN is a group of community activists who work to preserve and protect nature in San Francisco.

David Romano