Preserving the Dark Skies of Los Angeles County

In Los Angeles County - home to millions - members of the public and the county government are making the effort to inform, educate about, and improve the regulation of outdoor lighting to benefit today's and future generations. What follows is one of the most impressive introductions on the need for the mitigation of light pollution I've ever read.

Written by a field deputy from the Board of County Supervisors Office, it serves as an outstanding example for other communities that truly wish to conserve the beauty and ecology of their natural nighttime environment.

Protecting a Vital Resource

Los Angeles County, with its remarkable geographic diversity, is home to an array of unique geologic features that collectively form a rich tapestry of natural and ecological resources. Despite being one of the most populous counties in the United States, it is also home to significant rural areas, many of which are unincorporated and sparsely populated. These regions, including the San Gabriel National Monument, Angeles National Forest, and portions of the Mojave Desert in the northern High Desert, have historically preserved the beauty of dark night skies due to minimal human development. These vast, undisturbed and minimally disturbed areas remain havens for natural darkness. They face increasing threats from the proliferation of modern lighting technologies, such as LEDs and other high-intensity lighting systems with varying color temperatures. Without deliberate intervention, these invaluable natural resources are at risk of further degradation.
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Dark skies are fundamental to life on Earth, tied to the natural rhythms established over billions of years by the planet’s rotation and orbit around the sun. For millennia, living organisms have evolved in harmony with cycles of light and darkness, but the advent of artificial light at night has disrupted this equilibrium. Light pollution, broadly defined as the excessive, unwanted, or inappropriate use of artificial light, has profound consequences for ecosystems, wildlife, human health, and energy consumption. For nocturnal species, which make up nearly half of all organisms on Earth, darkness is a critical component of their habitat, guiding essential behaviors such as navigation, mating, nesting, and predator evasion. Plants and ecosystems are also affected, as artificial light interferes with growth, flowering, and dormancy cycles. For humans, light pollution disrupts circadian rhythms, wastes energy, and diminishes opportunities to experience the profound connection of observing the night sky, severing cultural and historical traditions of stargazing and celestial navigation.

​Globally, approximately 80% of people now live under light-polluted skies, and only 20% can still view the Milky Way. Human infrastructure introduces artificial light into places and times it does not naturally occur, with significant unintended consequences. The intensity, color temperature, and direction of artificial lighting contribute to these effects, and research increasingly highlights the adverse impacts of light pollution on biodiversity, human well-being, and even climate change. In parks and protected areas, even distant light sources can degrade habitat quality. The National Park Service's Night Skies Team has documented light pollution, including sky glow, originating up to 200 miles away from its source, underscoring the need for comprehensive regional strategies to mitigate its effects.

In Los Angeles County, efforts to address light pollution have included the establishment of the Rural Outdoor Lighting District (ROLD), which aims to preserve and promote dark skies in rural unincorporated areas. The ordinance includes requirements for shielded and angled lighting to prevent light spillover, minimize light pollution, and protect the County’s unique natural and cultural heritage. By maintaining dark skies, the ROLD seeks to preserve the relationship between residents and their environment, support astronomical observation, protect wildlife dependent on natural darkness, reduce energy waste, and balance lighting needs for safety, security, and recreation. However, the ROLD has not been updated since 2012, despite advancements in lighting technology and a growing understanding of light pollution’s impacts. Regular evaluations and updates are necessary to ensure the ordinance remains effective in addressing current and future challenges. Since the rise of LEDs and other technologies has altered the landscape of outdoor lighting, the County must remain vigilant in adapting its policies to protect this critical resource.

Natural darkness is not merely a scenic resource valued by stargazers and astronomers; it is an essential element of ecological and biological processes. According to the U.S. Fish and Wildlife Service, natural darkness is integral to preserving ecological continuity, including enabling nocturnal species to thrive and supporting natural processes such as free-flowing rivers and unaltered wildlife habitats. Many of the darkest skies in the nation are found within national wildlife refuges, but these areas are not immune to light pollution. Over the past five decades, night sky quality has steeply declined, making the preservation of darkness a nationally significant issue. The absence of artificial light is vital to nocturnal species that rely on natural patterns of light and dark for survival, underscoring the importance of protecting dark skies not just for aesthetic or cultural reasons, but as a cornerstone of ecological health.

In addition to revising and strengthening the ROLD, enforcement must be addressed. Communities have frequently reported that enforcement of the ordinance is insufficient, and current efforts are hampered by staffing and technological limitations. Exploring innovative enforcement solutions, such as automated compliance monitoring and community reporting mechanisms, could help ensure adherence to the ordinance. Updated policies should also address replacing failing or outdated lighting with compliant alternatives and introducing phased timelines for retrofitting existing non-compliant lighting systems. Reducing light pollution offers numerous benefits, including enhanced visibility of stars, improved conditions for wildlife, better human health and well-being, energy savings, and a renewed connection to the night sky. Beyond ecological and cultural considerations, reducing light pollution represents a commitment to sustainability and environmental stewardship.
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Los Angeles County has a responsibility to preserve its dark skies for current and future generations. By revisiting and enhancing the ROLD, strengthening enforcement, and embracing advancements in lighting technology, the County can protect its natural environment, cultural heritage, and biodiversity. Preserving the night is not only an ecological and cultural imperative but also a vital step in ensuring the harmony and health of both human and natural systems under the timeless beauty of a star-filled sky.