Guardians of the Night: Part 1
January 2025
At DW Windsor, we remain committed to responsible lighting practices. To further this commitment, we recently interviewed leading Dark Sky experts and consolidated their insights into a five-part series called Guardians of the Night. These articles illuminate the impact of light pollution and propose practical steps to mitigate it. Grounded in expert knowledge and research, these recommendations serve as a guiding framework for sustainable nighttime lighting solutions.
Part 1 - Light pollution: the ecosystem impact and recommendations for reduction
The following article provides thought-provoking insights into the impact of light pollution and practical steps to guide regulatory and ethical practices to make responsible lighting a reality.
The origin and impact of light pollution
Light pollution impacts all living things, including the biodiversity of plants (Asfuroglu, Dark Skies - Interview, 2024), and in general, it seems that everywhere we put light into the nighttime environment, it has a detrimental impact (Tonkin, 2024).
Dark Skies create a habitable environment that supports nocturnal activities including migration, pollination and foraging. Therefore, the direct interference of artificial light at night (ALAN) creates instability in the ecosystem where-by nocturnal species can become confused and at risk of human-related dangers or predators (Yakushina, 2024).
T.S. Wiley’s "Lights Out: Sleep, Sugar, and Survival" explains how artificial light messes with animals' natural rhythms, leaving them disoriented and vulnerable (Wiley, 2001). Sea turtles, for instance, rely on moonlight to find their way to the ocean, but bright beachfront lights can lead them astray and into the path of danger (Mazhar, 2024).
But it’s not just turtles at risk. The "Journal of Applied Ecology" highlights how ALAN throws off the natural order for a wide range of creatures, from insects to mammals, and disrupts biodiversity (Davies et al., 2022). Moths, the unsung heroes of pollination, are particularly hard hit. Less moth action means fewer plants, and that’s bad news for ecosystems (Mazhar, 2024).
Outside of the animal kingdom, humans are negatively impacted by ALAN, specifically blue light. Our circadian rhythm becomes stressed, meaning the human body is restricted from unwinding at its natural point, nighttime. Therefore, a decrease in rest has been found to negatively impact one’s ability to retain information, our natural immunity, and increase ailments such as obesity, diabetes and hypertension (Tonkin, 2024). Furthermore, a study published in JAMA Psychiatry found, "Living in brightly lit environments can lead to higher rates of mental health issues."
But even more alarming are the studies that have identified the rise in breast, colorectal, prostate, and endometrial cancer that can be linked to the dysregulation of the melatonin hormone which is produced at nighttime. ALAN is therefore leaving a trail of lasting damage on the human body (Bissell, 2024).
In rapidly growing urban areas like Dubai and New York City, the night sky has almost vanished under the urban glow (Mazhar, 2024). The International Dark-Sky Association points out that cities around the world, including those in the Middle East and North America, are losing their natural nightscapes because of relentless artificial lighting (IDA, 2023). But this also poses the question as to whether socio-economically disadvantaged groups are at a higher risk of the adverse effects of artificial light, notably nighttime shift workers and those living in urban areas (Asfuroglu, Dark Skies - Interview, 2024). Furthermore, it’s not only light pollution we need to be concerned about. Research has identified that the urban glow terminates air cleaning processes, thus increasing city air pollution (Yakushina, 2024).
The key is to “use the right light, at the right time, in the right place, and switch it off when you don't need it.” We should focus on the use of warm colour temperatures because we understand that cold and even natural light has a significant amount of blue within the spectrum which then scatters further in the atmosphere.
Steps to negate light pollution
As businesses and end users, we can each take steps to be more sympathetic to our surrounding environment and limit the impact of light pollution on our ecosystems. To do that, we must ensure that light is appropriate for its task and environment so it can meet the needs of the user but does not adversely impact wider receptors (Oakley, 2024).
The key is to “use the right light, at the right time, in the right place, and switch it off when you don't need it.” We should focus on the use of warm colour temperatures because we understand that cold and even natural light has a significant amount of blue within the spectrum which then scatters further in the atmosphere. Red light which astronomers use has zero blue within it, meaning whatever is astronomically friendly is also biodiverse-friendly (Asfuroglu, Dark Skies - Interview, 2024).
As businesses, we have the responsibility to advise and guide on the five principles of responsible outdoor light at night (ROLAN). “We should promote to clients ‘why’ we should adhere to it. By doing so, it then becomes normal practice, and in turn, we will see others follow suit” (Bissell, 2024). It is suggested that altering light exposure depending on the use and fulfilment of space should infer the percentage of the function used, for example, turning it down the fewer people are present, or adopting motion sensors and timers (Mazhar, 2024). Additionally, shielded and downward lighting fixtures minimise skyglow, in turn meaning a reduction in atmospheric scatter “ensuring they illuminate only where needed” (IDA).
Institutions must take responsibility for educating individuals and setting guidelines. This requires “local governments and NGOs to implement existing environmental laws, not necessarily writing new ones to add confusion to the matter” (Yakushina, 2024).
Applying these principles and best practice approaches not only limits light pollution, but it would also dramatically reduce energy consumption where the UK itself wastes £1 billion per annum (Asfuroglu, Dark Skies - Interview, 2024). Collectively, we can make a difference and set the standards moving forward to achieve responsible lighting that limits environmental impact.
About the authors
Andrew is a past president of the Society of Light and Lighting and a Partner at Ridge and Partners LLP. He has worked in lighting design since 1996, currently leading Ridge’s lighting design team. During his presidency, Andrew developed guidance to protect the night sky, supported early-career professionals, and raised the profile of lighting specialists within the construction industry. His projects span various sectors, focusing on improved design processes, enhanced environments for both people and wildlife, and reduced energy use and material waste. More recently, Andrew has contributed to large-scale Dark Sky initiatives in the UK and Saudi Arabia.
Kerem is the founder of Dark Source, an award-winning lighting design studio in the UK and Ireland guided by environmental principles. After earning an MA in Architectural Lighting Design from Wismar University in 2010, he spent 7.5 years at Speirs Major before establishing Dark Source in 2019. Named a Dark Sky Defender by Dark Sky International, Kerem has led projects such as the Plas Y Brenin Outdoor Centre, Presteigne Dark Sky Community, Newport Dark Sky Masterplan, Cloughjordan Ecovillage, Clwydian Range & Dee Valley, and Dark Sky Planning Guidelines for Cumbria. His work highlights low-impact solutions that harmonise built environments with nature.
Yana is a lawyer, researcher, and dark sky protection educator currently pursuing a PhD at the University of Ghent under the Horizon EU PLAN-B project. She also serves as a scientific coordinator, shaping regulations that recognise light pollution as a critical environmental issue. As Deputy Executive Director at the Space Court Foundation Inc., she oversees projects like the “Big Book of Space National Law.” Yana has contributed to international legal research with the EU Commission, DarkSky International, Starlight Foundation, the International Astronomical Union, and UNOOSA. In 2023, she co-founded the Belgian dark sky organisation Living Night (DarkSky Chapter).
Dan Oakley is a dark sky expert and founding director of Darkscape Consulting. He previously served as the Dark Sky Officer at the South Downs National Park Authority, overseeing the IDA International Dark Sky “Moore's” Reserve application and developing planning policies and technical guidance. Dan chairs the International Dark-Sky Association (IDA) Places Committee and is a founding member of IDA-UK. He also established and coordinates the UK Dark Skies Partnership to reduce light pollution. With degrees in physics, wildlife management, and environmental policy, Dan has earned multiple accolades, including the IDA Dark Sky Defender award.
Hiba is a distinguished Architectural Lighting Designer and Associate IALD based in Dubai, serving as a key figure at Light Touch PLD. She leads the design of innovative lighting solutions for international public, urban, and interior projects, emphasising sustainability and dark sky practices. Recognised for her pioneering approaches, Hiba was a finalist in the CIBSE Research Competition for dark sky preservation strategies and has won accolades such as the SIGNIFY Global Lighting Design Awards and LIT Awards. By merging technical proficiency with creative vision, she is redefining architectural lighting, championing solutions that safeguard natural ecosystems and enhance urban landscapes.
Steve is a Fellow of the Royal Astronomical Society who has authored numerous articles and books on practical astronomy. For over 40 years, he has taught astronomy to adults and children, sharing his passion through lectures, workshops, and hands-on sessions. He serves as the Dark Skies Advisor to both the Federation of Astronomical Societies and the International Dark Sky Reserve at Cranborne Chase National Landscape. In addition to speaking at astronomical societies in Britain and abroad, he regularly addresses Rotary, Probus, and U3A groups. Steve also writes a monthly column for BBC Sky at Night Magazine, reviewing equipment and literature.