Improving the Light Environment for the Starry Skies and the Natural Environment

Kozushima, one of the islands in Tokyo‘s Izu Island chain, and  Bisei-cho, a mountainous area in Ibara City, Okayama Prefecture, were certified as “International Dark Sky Places” by the International Dark-Sky Association for their outstanding efforts to protect the beautiful night skies. In order to obtain the “International Dark Sky Places” certification, most of the area’s security lights and street lights were replaced with dark sky friendly lighting  featuring 0% upward flux ratio and incandescent color, which completely changed the atmosphere of the village. Tokumasa Ogawa  from Kozushima Village and Kenji Fujioka from Bisei Town talked about their motivation and efforts for the coexistence of night skies, nature, and the lives of residents.

Mr. Ogawa describes Kozushima Village’s efforts as follows. With the cooperation of the Tokyo chapter, International Dark-Sky Association and the Tokyo Metropolitan Government, an ordinance was enacted to prevent light pollution, and at the same time, with the help of IWASAKI ELECTRIC CO.,LTD., dark sky friendly lighting fixtures that conform to the ordinance were manufactured. From April to July 2020, 83% of all 584 outdoor lights on the island, including security lights, were successfully replaced. There were no complaints from the residents, contrary to everyone’s concern at the start of the project, and in the end, the project was welcomed by the majority of residents in the village, who can now enjoy the stars themselves. Mr. Ogawa says that the project made him realize that the brightness of the streetlights may have been too disturbing for the villagers.

On the other hand, Mr. Fujioka explains Bisei Town’s effort as follows. As the first town in Japan to enact an ordinance for light pollution prevention in 1989, Bisei Town has been working for more than 30 years to address light pollution and develop the town as a “town of stars”. With the technological shift to LED street lighting in recent years, however, the residents began to feel a sense of crisis for their renowned “town of stars”, as some people mentioned that it had become harder to see the stars now than in the past. It was after hearing those voices that he learned about the “International Dark Sky Places” certification program, and he decided that this world-standard certification was inevitable for the future revitalization of the region, mainly tourism.

In addition, in November 2019, before the town revised its ordinance and replaced the lighting fixtures, the moderator Nobuaki Ochi, with the help of Mr. Fujioka, conducted a questionnaire survey of the residents. The questionnaire asked, “As a resident of Bisei, are you proud that the light pollution prevention ordinance was enacted?”. The results showed that about 80% of the respondents answered “very proud” or “a little proud,” indicating that the effort is being supported by most of the residents. On the other hand, there were those who felt that the lighting is too dim after the replacement, and Mr. Fujioka noted that he will continue to gain understanding from the residents.

Mr. Ochi, the moderator, concluded by saying that the efforts to obtain the “International Dark Sky Places” have brought about an increasing number of opportunities for them to be exposed to mass media and the web, and he hopes that these activities would raise awareness of light pollution and provide opportunities for many people to think about the ideal form of lighting in the future with consideration for the environment.