Environmental and astronomical experts are urging residents throughout the state to reduce outdoor lighting in order to prevent the spread of light pollution.
Light pollution, caused by excessive artificial lighting, is not merely a nuisance for neighbors, but poses a growing threat to both the astronomy industry and many endangered animals, said speakers at an Oahu lighting seminar Wednesday.
University of Hawaii astronomer Richard Wainscoat said that because of Hawaii’s location along the equator, the state’s unspoiled night sky actually is darker than any other night sky on the U.S. mainland. But light pollution in some places, particularly Honolulu, has removed the view of the stars from the night sky.
“We’ve lost being able to see the Milky Way on Oahu, probably forever,” Wainscoat said.
Although Wainscoat said the Big Island’s nights are still darker than on Oahu, he added that the telescopes on Maunakea are particularly susceptible to brightness increases.
“If the night sky gets just 10% brighter … our telescopes effectively become 10% smaller,” Wainscoat said, although he noted that the sky above Maunakea summit has not seen such an increase yet.
Sheldon Plentovich, an ecologist with the U.S. Fish and Wildlife Service’s Hawaii and Pacific Islands Program, said artificial lighting presents a threat to already endangered species such as green sea turtles.
While the impacts of artificial lighting on sea turtle hatchlings are well-known — hatchlings attempting to crawl from their nesting sites to the sea can easily be disoriented by lights and be led away from the water to die — Plentovich said Pacific green sea turtles’ nesting sites are being jointly threatened by light pollution and climate change.
With Hawaii nesting sites becoming increasingly compromised by light pollution, Plentovich said the darkest sites within the turtles’ territories are largely within the French Frigate Shoals, which are themselves extremely threatened by climate change. She added that, because of bright lights’ impacts on the behaviors of turtles, seabirds, insects and more, it should be considered a form of habitat loss.
Graceson Ghen, Hawaii County manager for Hawaii Energy, said the Big Island has more robust lighting ordinances to protect the night sky than on neighbor islands, such as a requirement that all outdoor lighting have less than 2% “blue light content.” The blue end of the visible light spectrum diffuses through the atmosphere more effectively than other parts of the spectrum, and can appear brighter to the human eye.
Although the panel Wednesday did not recommend any specific lighting policy changes at the county or state level, Ghen added there are still ways residents and businesses can improve lighting to make nights darker, including using dimmable or shielded lighting that only lights essential areas when people are there.
Wainscoat added that although there are numerous lighting violations that could incur a $500 fine on the Big Island, there is very little enforcement, if any.
Email Michael Brestovansky at mbrestovansky@hawaiitribune-herald.com.