​UCLA Study: Light Pollution Decreasing ​at SoCal’s Coastal National Parks

LOS ANGELES, CA -- A study published Wednesday found that the amount of light pollution produced within Southern California’s three coastal National Park Service units has not significantly changed, and in one case has decreased, over the past two decades.

UCLA researchers, working with National Park Service scientists, examined satellite data between 1992 and 2012 to see how lighting levels were changing from within National Park units. They concentrated on lights visible within the park boundaries and found that nighttime lights:

• decreased inside Cabrillo National Monument in San Diego,
• remained extremely low within the boundaries of Channel Islands National Park, off the coast of Los Angeles, Ventura, and Santa Barbara counties, and
• have been relatively stable within Santa Monica Mountains National Recreation Area, which is found within and to the west of Los Angeles.

“The good news is that we now have a baseline measure of the lighting conditions within Southern California’s coastal national park units. Now we can work with people in the cities in the surrounding regions to decrease their contribution to the problem and conserve night skies,” said Tom Gillespie, the study’s lead author and a professor of geography at UCLA. “Rarely are ecological problems remedied this easily, through small actions by large numbers of people.”

Gillespie and his team were commissioned to analyze nighttime lights for the Mediterranean Coast Network.

The study is a first step in long-term light pollution monitoring around the parks and establishes a standard methodology for ongoing research. Results are used by park managers for planning, management, and decision-making.

--Image via National Parks Service