Night light can be beautiful. It can be a source of guidance and create a sense of place and belonging for people to relax and enjoy themselves as the dark night falls. However, excessive artificial light has a negative impact on people and the environment, disrupting delicate ecosystems and compromising biodiversity.
Light pollution
Light pollution, and the excessive and inappropriate use of artificial light at night, affects human, plant and animal health and our ability to experience the wonders of a starry night sky.
Research shows that light pollution is increasing: The artificially lit area outside the Earth grew by 2.2% annually between 2012 and 2016. The damage caused by – and action needed to reduce – water pollution and air is stable now, but there is an argument that light pollution should receive a similar level of consideration. This is especially important when talking about the natural environment, and the impact light pollution can have on ecosystem function and stability.
Climate and biodiversity emergencies can be mitigated if we all act now. As lighting designers and ecologists, we have a responsibility to protect our natural environment, including the night sky.
Amy Rennie, Associate Lighting Designer
At Buro Happold, we design, advise and consult on the best solutions for people, place and planet. Our multidisciplinary work takes into account a variety of factors; the ecology and biodiversity of our planet and human well-being and safety are equally important in the design process. Grouping multiple criteria together in this way creates a more sustainable and equitable outcome.
To reduce the harmful effects of artificial light on the atmosphere, we must build sustainability in the work we contribute, for our communities and ecosystems. In the build-up to events like COP27, government bodies have expressed the need for urgent action against the climate crisis and biodiversity. As experts in the building and outdoor environment, we have a critical role to play in realizing these outcomes.
The importance of darkness for humans
Darkness is natural for our circadian cycle. Preserving darkness is important for our sleep, our biology and the health of our own ecosystem. Light is key to keeping our internal clock in tune with the environment. Outdoor lighting with cooler white light with shorter wavelengths can affect these natural sleep patterns.
Light pollution doesn’t just affect people; it affects all living things. That’s why Buro Happold’s lighting and ecology teams work so closely together.
Amy Rennie, Associate Lighting Designer
Disruption can cause sleep disorders linked to health issues such as obesity, stress, cardiovascular disease and decreased cognitive and motor skills. Exposure to artificial light at night suppresses the production of melatonin, the main sleep hormone that helps reduce fatigue and regulate sleep cycles.
Buro Happold lighting designer Amy Rennie co-chairs the UK chapter of The International Dark Sky Association. He is passionate about working to address light pollution and believes, “We need to celebrate the dark sky, protect our view of the stars and allow everyone to connect with nature. As a lighting designer I always think of the role of people in the balance of light and nature, and I want to inform the impact of light pollution on people, ecology and biodiversity.
“Each of Buro Happold’s lighting and ecology teams share these values. It is a central part of our ethos to embed and share these principles in our designs, and teach our worked, the good that is in darkness for all.”
The importance of darkness for wildlife
Nighttime lighting can also disrupt wildlife: species that are nocturnal and adapted and/or dependent on dark environments are particularly affected by light pollution. Such species have developed enhanced senses such as smell, sight, hearing or echolocation. These adaptations to dark environments can be important for their ecology (e.g. migration patterns), behavior and survival – examples of the benefits of these adaptations are avoidance of daytime active predators and reduction of competition for resources.
Dark skies are essential for species that depend on darkness for their daily existence. The collaboration between lighting designers and ecologists means that we can include wildlife-sensitive lighting designs in our projects, which is an important element in their conservation and in dealing with the biodiversity crisis.
Monica Lozano Subiranas, Ecologist
Inappropriate light spills and light from new developments may harm some wildlife. Hatching turtles need a dark horizon at sea level to help them orient from the hatched beach to the safety of the ocean. Bright buildings and brightly lit urban areas can disrupt migrating birds, attracting them to our cities and causing many birds to be injured or killed in construction collisions each year.
In urban areas, we must also consider the importance of protecting existing ecological and dark corridors (eg rivers) from light pollution. Where new ecological habitats or corridors are created, careful planning of artificial lighting must ensure that the biodiversity value of these important natural corridors remains for nocturnal species.
At Mayfield Park in central Manchester, our team ensured that sensitive lighting design was implemented so that the river remained a dark corridor suitable for bats to search and commute. Our work for the University of Bristol’s Temple Quarter Enterprise Campus involved ensuring that the specified lux level limits on the waterways and associated banks were met.
How can we balance light and darkness for people and for nature?
Our challenge, when considering lighting design and ecology, is to find the right balance between function, aesthetics and the environment. This does not mean that there is no light, but we suggest that light should be thought of as a whole, taking into account the environmental, ecological and human aspects.
Controlling lighting through smart control systems, reducing light levels during the progressive hours of the night and designing according to environmental conditions and surroundings help to protect the night and reduce light pollution (and its negative effects of light pollution in local ecosystems). Managing the spectral power distribution (SPD) of light and designing to use appropriate responsible outdoor lighting solutions in a project can improve the outdoor environment for everyone.
We understand the importance of the intersection of lighting design and consideration of biodiversity and integrate it into our projects wherever we can. This article provides a snapshot of our work. The Eden Project North is an extension of the Eden Project in Cornwall, located in the north-west of England, which focuses on education, ecology and community. Such a project requires attention to the impact of the lighting design. Our specialist lighting team created a bespoke, low-energy and low impact lighting strategy to preserve the Ramsar conservation area, the dark skies over Morecombe Bay, and provide the right level of light for users. .
We have international experience working with wildlife experts to apply the latest development planning and zoning techniques. For example, turtle eye view modeling from different locations on nesting beaches helped guide development placement. Along with physical screening, it aims to ensure that the nesting beaches and surrounding areas remain properly dark, helping the turtles to continue to follow their natural behavior of nesting next to the areas of development.
Light and darkness must be considered in the same breath. The use of both elements creates spaces that are very beautiful for people to explore and experience a landscape of light and darkness, while ensuring the conservation of nocturnal species. Our work at the Grace Farms arts and community center in Connecticut, USA, demonstrates its importance.
The lighting design focuses on maintaining a sense of connection between the natural landscape and the glass pods that place the facilities at the center. This is done by strategically placing outdoor lighting so that it serves the purpose of users around the building without disturbing from a distance, and by balancing the respective levels of illumination inside and outside, most by dimming the interior lighting. The project received a Lumen Award of Merit in 2016.
Mitigation measures
Rethinking the way we light our outdoor environments can be complex, but it can also mean asking some straightforward questions and taking simple actions. We must consider the interrogation briefly. Is the lighting requested necessary and appropriate?
The International Dark Sky Association explains some key principles for responsible outdoor lighting. All lighting should have a clear purpose, and be used only where and when needed. For example, lights can be turned off when not in use (especially in summer) to preserve darker spaces, and shielding and proper direction means that light does not escape beyond where it is needed. Low light levels must be considered; it is best practice to use the lowest light level possible.
The use of light is available; it should be used only when it is useful and achieves its purpose. The color of the light is also relevant. If white light is needed, it must be warm. Lighting that emits little ultraviolet light or warm lights with long wavelengths protect our environment, promote our connection with nature and enhance visibility and appreciation of the night sky.
