America’s Rapid Adoption of LED Lighting Contributes to Growing Light Pollution Issue
LED lighting has quickly gained popularity in the United States due to its energy efficiency and cost-saving benefits. However, this widespread adoption of LED lighting is causing an unintended consequence – the obstruction of star visibility due to light pollution.
A recent study published in the journal Science reveals that the night sky is getting 10% brighter each year, primarily due to the increased use of LED lighting. Experts agree that LED lights, particularly the bright white ones, exacerbate the problem of light pollution.
Stephen Hummel, the dark skies senior outreach coordinator at the University of Texas’ McDonald Observatory, explains that LED lighting is making the problem much worse. A light pollution map of the United States shows that the issue is prevalent throughout the country, affecting not only big cities but also suburban and rural areas.
The excess artificial light results in sky glow, obscuring the stars and diminishing the view of the night sky. Ohad Shemmer, an astronomer at the University of North Texas, highlights that the Milky Way and fainter stars are gradually disappearing from view.
The rapid switch to LED lighting is driven by government regulations. Congress mandated in 2007 that all lightbulbs be three times more efficient, and this policy took effect on August 1 of this year, essentially banning incandescent light bulbs in favor of LED and compact fluorescent lights.
Despite the energy-saving benefits of LED lighting, research shows that excessive nighttime light can disrupt sleep cycles and contribute to health issues such as certain cancers and heart problems. It also negatively impacts insect populations that rely on darkness to navigate and causes the death of millions of birds each year as they collide with brightly lit buildings.
The McDonald Observatory, located in the Big Bend region of West Texas, houses the largest telescope of its kind in the world. A dark night sky is crucial for its astronomical work. To protect the night sky, the Observatory played a significant role in establishing the Greater Big Bend International Dark Sky Reserve, covering a vast area of West Texas and parts of northern Mexico.
The Reserve is a collaboration of parks, communities, and local groups committed to adopting better lighting practices. They replace bright white LED streetlights with amber-colored ones that minimize light scattering and install covers that direct light downward. The Alpine City Council enacted an ordinance regulating outdoor lighting and requires businesses and homes to convert to dark sky-friendly lighting within five years or face daily fines.
The American Lighting Association, representing lighting manufacturers, acknowledges the extent of light pollution and offers shielded outdoor light fixtures to redirect light away from the sky. The efforts taken within the Greater Big Bend International Dark Sky Reserve have shown promising results, with a 20% reduction in nighttime light pollution since 2020.
However, the problem extends beyond small communities. Major cities like Los Angeles, Chicago, and Phoenix are also replacing overly bright streetlights with dark sky-friendly alternatives. Hummel asserts that solving the issue of light pollution is not a matter of finances or infrastructure but rather awareness. He emphasizes that light pollution is entirely reversible and can be resolved by simply flipping a switch.