Mar 17, 2022

We have the power to hit the right notes in outdoor lighting

By Jane Slade

Light and sound are shared sensory experiences across the strata of life. Yet we utilize entirely different frameworks in how we apply them within shared spaces. Much can be learned from our intentional use of sound. In our lives, communities share an agreed upon quietude each night. In the art of music, each note is dynamic and intentional. From simple compositions to complex symphonies, musical instruments call and respond precisely and harmoniously to share the temporal space

In our current exterior lighting practices, however, there is a grave lack of regulation or intention. Each night, bright light blares all over the planet, regardless of need. If this were a piece of music, it would be like playing one note on a French horn at the same decibel level all night long. The monotony of bright light at night has profound and surprisingly nuanced ecological impacts, transposing and distorting the orchestra of circadian rhythms for all living things. There is no way to calculate the toll of such a massive form of climate change, nor to understand how such a rapidly changing environmental factor will cascade through our ecosystems.

Yet we already possess the technology to overcome light pollution. Today, smart lighting controls are the single most important tool of sustainable lighting design, allowing instant on-off and dimming control down to a single fixture, public or private. Dark-sky lighting is also critical; however, controls open up the ability to conduct complex lighting systems that can improve and adapt over time to the needs of communities and ecosystems.

We have never had such a granular ability to control our lighting systems. In the future, sustainable lighting design will
make the most of this robust functionality by intentionally controlling all exterior lighting over the 24-hour period of the natural daylight cycle and throughout the seasons. This includes curating wavelengths of light to reduce impact upon wildlife, as well as the tone and color of light to enhance human experiences and activities. Through data collection, we will fine-tune lighting over time to focus upon visibility and precise design goals rather than default to constant, monotone brightness, even allowing communities to reduce overall light levels or adopt periods of Full Darkness Hours (FDH)1 in their community darkness plans.

The irony is that the biggest barrier to solving light pollution is awareness, not a lack of technological solutions. Currently, we are still in the grassroots of advocacy and debunking common misconceptions is tricky. There are two powerfully counterintuitive gateways that a person must go through before fully comprehending the gravity of light pollution and how we got here. If we can let go of these two limiting ideas, we release to a much broader set of truths and best practices.

The first misconception is to think of light pollution as only a nuisance, rather than a critical aspect of climate change that threatens the health and wellbeing of all living things, from reducing pollination, to altering bat behaviors, interfering with animal migrations, changing the way plants grow and impacting human sleep.

The second misconception is the belief that more light is safer. Inconclusively, there are many instances where having light improves safety and a feeling of safety, and many where too much light reduces visibility and creates blind spots. The issue with this belief is that it insinuates that the quantity of light is directly related to the amount of safety, and this is not always true. In fact, a recent study showed the opposite. When lights went out in a certain part of a city, crime shifted to where the light remained on; crime followed the light.2

If we look at the current trajectory of exponential light pollution growth on the planet, we must ask ourselves, is our longterm goal to have night emulate the day?

As design professionals, we are caught between the codes, uninformed decision-makers and conservation. The advocacy and best practices have not yet reached the decision-makers, making each project feel like an experiment in how to have the conversation. We are often forced to move forward with exterior lighting designs where litigious thinking overrides best practices in light levels, color and optical selection. Controls are often abandoned too.

Moreover, the widely held belief that more light is safer drives the development of human laws that are out of alignment with natural laws, casting natural darkness out to the edges of modern existence. We are in dire need of leaders and voices to properly educate the public on this unchecked natural disaster.

As the experts, we must take greater responsibility for light pollution, a critical aspect of climate change that falls within our field. We must lead the way by incubating the study of natural darkness, tenebrisology,3 at our conferences, in our professional organizations and in our design practices. We must advocate within our communities, foster conversations so they have already taken place when projects get started, and educate our clients so they ask for the right things.

In addition, perhaps there are lessons we can borrow from the framework of sound to recreate a more sustainable relationship to light. Each night, we cultivate silence, but we leave the lights on. In the nighttime soundscape, we allow our world to go quiet. Alarms sound only as needed. In music, every point of a symphony is intentional, including moments of great restraint, sensitivity and quietude.

Controls open up unparalleled opportunity to cultivate safe and sustainable darkness, and to reclaim much of the darkness we have lost to unintentional light pollution. By allowing experimentation, adaptation and reduction in light levels over time, communities are empowered to develop intricate lighting and darkness plans to use light only as needed, and to find a deeper understanding of the balance between lighting for safety and human activity and maintaining the integrity of the natural darkness and the night sky for wildlife and human health.

The metaphor of a symphony aspires to create intelligent compassion and regard for the shared temporal spaces that light and darkness pass through. Smart and adaptive lighting controls allow us to conduct our lighting to live more symbiotically with wildlife and other humans through feedback and understanding. The natural daylight cycle is dynamic, and there is beauty and vitality to be found at all points, including in the silence and the darkness. We could do so much more with less light, both in intensity and over the course of time. If we combine lessons from our intentional use of sound with the robust power of lighting controls, the future of lighting is a symphony of harmonious, responsive and resilient design for all living things.


1 Slade, Jane. “Darkness as a Beacon.” LD+A, Volume 51, no. 6, June 1, 2021.
2 Chalfin, Aaron, Jacob Kaplan, and Michael LaForest. “Street Light Outages, Public Safety and Crime Displacement: Evidence from Chicago.” SSRN Electronic Journal, January 27, 2020.
3 Slade, Jane. “Wield the Power.” LD+A, Volume 51, no. 11, November 1, 2021.


Jane Slade

Jane Slade

Jane Slade, MID, LC, is the specification sales manager for Speclines in Massachusetts, a lighting manufacturer’s representative agency specializing in outdoor lighting for municipalities, universities, corporations, commercial developments and transportation agencies. Ms.... More info »