Global Lighting Association releases position statement on nighttime lighting

Recently, the Global Lighting Association (GLA) released a document titled "Nighttime Lighting: The Importance of Quality Lighting and Maintaining Darkness at Night", clarifying the GLA's views on nighttime lighting. The China Illumination Society has translated the full text for your reference. The original document can be downloaded by clicking "Position Statement".

Night Lighting: The Importance of Quality Lighting and Nighttime Retention

The Role of Night Lighting

In modern society with a 24-hour cycle, lighting is crucial for providing human safety and comfort in outdoor settings during sunset and sunrise, or in similar locations such as parking lots, streets, alleys, and pedestrian tunnels.

Road lighting greatly promotes traffic safety, enabling road users to detect obstacles, moving vehicles, and other hazardous situations. In outdoor public spaces, a good perception of the surrounding environment and the ability to observe others from a sufficient distance are crucial for creating a positive social atmosphere and ensuring public safety. Lighting can influence the character of an area, thereby affecting the mood and behavior of its inhabitants. Obviously, professionals working between sunset and sunrise, such as those in emergency services, industry, transport, and logistics, rely on good lighting to ensure safety and effectiveness during their work. Existing outdoor application standards set the most basic requirements for lighting to achieve these functions.

The Importance of Nighttime Protection

The evolution of life on Earth and human history have always been influenced by the natural day-night cycle of sunlight. Therefore, residents and the biosphere on Earth have developed a biological dependence based on this cycle. At night, introducing electric lighting into our buildings and natural environments affects biological processes, limits humanity's ability to explore and study the universe, and diminishes the pleasure of seeing stars in a pitch-black night sky. For these reasons, achieving nighttime preservation in a respectful manner is crucial for nighttime lighting schemes.

Poor quality, incorrect specifications, and improper installation of outdoor lighting can damage the night environment while wasting energy. Illuminating road edges, curbs, and sides can make people and animals near the road detectable. However, light spilling beyond useful areas can be harmful and should be avoided.

Spill light directed to areas other than intended affects nearby residents through glare or light intrusion (e.g., from an illuminated sports field); this is called obtrusive light (see Note 1). Other sources of light pollution are illuminated building facades and billboards. Uncontrolled upward light directed at the sky should be avoided, as it causes skyglow, hinders observation of the night sky, and may disorient wildlife. Light pollution causes energy waste; it can be reduced by using high-quality sensors to control or connect lighting equipment (see Note 2), and in many cases even prevented (see Note 3).

Special Area Lighting

Although light is extremely important for promoting human nighttime activities, in some special areas, certain activities and species require extra attention. To protect wildlife near densely populated areas, if necessary, precise lighting should be achieved through protective covers. When human safety and positioning are not a concern, lighting can be dimmed or turned off. By combining special spectrum with dimming or interconnected lighting, interference with nearby astronomical observatories or with nocturnal wildlife (such as migratory birds, bats, and insects) caused by outdoor lighting can be mitigated.

The International Association of Lighting Designers recommends

High-quality outdoor lighting is a shared responsibility of lighting designers, lighting fixture owners and operators, and lighting manufacturers.

1. Do a good job in lighting design

a. Choose an appropriate light source, looking beyond initial cost and energy efficiency to a broader perspective.

b. When applicable, make the requirements of special areas part of the lighting design.

c. Apply relevant outdoor lighting application standards to avoid over-illumination

2. Use high-quality lighting controls

a. Use sensors and controllers as much as possible

b. Use interconnected lighting for lighting management and maintenance

3. Use light only where needed

a. Use shielding and precise beams when needed to prevent light spill and intrusion

b. Use appropriate optical devices to prevent glare

4. Use light only when needed

a. Use electric lighting between sunset and sunrise according to human nighttime activities

b. Dim or turn off the lights when it is quiet

Note: 1. Intrusive light refers to stray light that causes annoyance, discomfort, distraction, or reduced ability to perform basic tasks such as viewing traffic signals (CIE ILV) due to its quantity or directionality.

2. Interconnected lighting can be defined as the connection of lighting, control devices, and sensors (wired or wireless) to enable automatic control of lighting operations.

3. Light pollution is the sum of all adverse effects of artificial light (CIE ILV).

Source: China Illuminating Engineering Society