Ruth Chittock, joint winner of the LI Student Travel Award 2017, visited the Great Basin National Park in Nevada to explore how landscape can ameliorate the health and well-being effects of light pollution

    © Euan Reed

    In the proposed age of the Anthropocene, ‘The Human Age’, we are changing the world around us at an unprecedented rate. Humans are physically altering the planet’s ecosystems on a global scale and the repercussions are becoming increasingly visible. In 2016, a group of scientists published the New World Atlas of Artificial Night Sky Brightness, illuminating the extent to which we are lighting up the environment we live in. In the same year, CPRE developed the Night Blight map, plotting levels of light pollution across the UK. It is no surprise to see that the highest levels of light pollution occur around towns and cities, but it is shocking to see just how brightly some of these cities shine. With an increasingly large proportion of the world’s population now living and working in urban environments, it is imperative that some consideration is given to the effects of light pollution on our physical and mental health. Harnessing electricity and creating artificial lighting, has been one of mankind’s greatest technological advances, but has our demand for twenty-four-hour illumination become excessive? The International Dark Sky Association (IDA), drivers of a worldwide campaign to tackle the loss of our night skies, certainly think so.

    Our increasing obsession with artificial nightlight means that light pollution in our cities is now prevalent. Considering that the majority of the population live in urban spaces, it is inevitable that millions of people across the globe will never get to experience the magical vista of the Milky Way, arching across the night sky where they live. This increase in light pollution does not only mean the loss of the natural heritage of our dark night skies, but it also has major adverse effects on the ecology in our cities and on our health as humans. Human life has evolved to follow a circadian rhythm; our physiological processes are influenced by the natural cycles of day and night, light and dark. A growing dependence on artificial lighting at night means that we are no longer experiencing true darkness and extensive research is beginning to reveal that this can have a negative impact on human health, leading to an increase in sleep disorders and depression, and increasing the risk of diseases such as obesity and even breast cancer.

    My interest in the subject of light pollution was originally sparked during my time spent living in London whilst studying for my Masters in Landscape Architecture. Having grown up in the countryside, with clear views of the night sky and freedom to experience the landscape at night, I was acutely aware of the light pollution in London. It was rare that I saw stars in the night sky; rather, an ominous orange glow above the rooftops. I soon realised that the light seeping into my room at night was not only an irritation, but it was physically interrupting my sleep. So began my interest in what light pollution is really doing to our health, and in the role landscape professionals can play in designing healthier places for people to live.

    This September, I travelled across America in search of the night. My journey began in San Francisco, one of the brightest cities on the West Coast, and took me all the way to the Great Basin National Park, a designated International Dark Sky Park, boasting some of the darkest skies in the country. I am fascinated with the idea of Dark Sky Parks as a retreat from the stresses of the bright city lights, but I also wanted to investigate ways in which we can use the knowledge gained from these spaces to improve the way that our cities are lit. Adding artificial light to our environment changes the habitat that we live in. It is well documented that this has negative effects on the plants and animals around us but we do not yet know the full extent of how it affects us as humans. If the natural processes of our body are controlled by the circadian rhythm, how do our bodies cope when day and night start to blur into one?

    Whilst in San Francisco, I met with Toby Lewis, senior lighting designer for ARUP. Toby explained how the different colours of the light spectrum affect our bodies: blue light wakes us up and red/orange light relaxes us. Cities around the world are in the process of upgrading street lighting systems to incorporate energy saving LEDs. Whilst there are benefits to the use of LEDs, the light emitted from them tends to be at the blue end of the spectrum which could be problematic. Blue light wavelengths suppress melatonin, the hormone which controls our natural cycles of sleep. In a natural cycle, levels of melatonin rise in the evening, remain high throughout the night, and drop in the morning. Blue LED street lighting at night would suppress melatonin levels in the evening, upsetting the body’s natural cycle, and keeping us awake when we should be sleeping.

    If we now understand how different colours of light affect the circadian rhythm, surely we could create a street lighting system of varying colours which automatically adjust throughout the early evening, night, and morning, to mimic the natural cycle of light. It could be possible to do this using tunable white LEDs which allow us to adjust the colour temperature of the white light output. Fitting tunable white LED systems in our towns and cities would allow us to provide appropriate colours of light throughout the night. It could also be possible to install street lights with sensors that adjust output depending on existing levels of ambient lighting. Recently, the San Francisco-based Civil Twilight Collective came up with the concept of a Lunar Resonant Streetlight. Sensors in the streetlight detect levels of ambient light and adjust the output accordingly, meaning that on a clear night with a full moon, little to no output would be required from the streetlight. Installing smart systems which automatically adjust colours and levels of light according to need would reduce energy use and light pollution.

    ‘I often think that the night is more alive and more richly coloured than the day’

    Vincent Van Gogh

    Escaping the bright lights of the city, I set out in search of a dark night sky. I arrived at the Great Basins National Park in Nevada at the end of the annual Dark Sky Festival. People travel from far and wide to experience the park at night, drawn by the complex beauty of a star filled sky. Whilst at the park, I met with dark sky ranger Annie Gilliland who talked me through the work that the park is doing to encourage people to enjoy the landscape at night. The park offers a popular ‘Full Moon Walk’, allowing visitors to experience the park in a unique way, and encouraging them to appreciate another side to the stunning landscape. Walkers are encouraged not to use head torches and instead, to trust in the illumination from the full moon to light their way. The park is also trying to educate people about the problems of light pollution with regular lectures, explaining the problems we are facing and what we can all do to help. Annie is well versed in this subject – she wrote her thesis on light pollution – and is now relaying her findings to visitors at the park. As well as discussing the ecological effects of light pollution, Annie’s lectures also touch on human health and the problems which she has experienced first-hand.

    The IDA requires the Dark Sky Park to limit artificial lighting, and where lighting is required, to fit suitably shielded lighting which is directed downwards. This way, the light is focused where it is needed, limiting the amount which escapes upwards into the sky. Replacing external light fittings is an effective way to reduce light trespass and after visiting the park visitors are advised on sensitive lighting solutions for their own homes, leaving encouraged that they can do their bit to help. Ensuring light is properly directed is an easy way to reduce light pollution in our towns and cities and should be considered in all future designs.

    I camped for three nights at the base of Wheeler Peak, the parks most arresting mountain and the tallest mountain in the Snake mountain range, to fully experience the landscape at night: I was not disappointed. After the sun had set each night, I was greeted with pristine starry skies and incredible views of the Milky Way. In the daytime, the vast basin landscape is streaked with sunlight and shadow. The isolated nature of the park means that any light pollution there is at a minimum.

    ‘The stars are glittering in the frosty sky,
    Numerous as pebbles on a broad sea-coast;
    And o’er the vault the cloud-like
    Galaxy Has marshalled its innumerable host’

    Charles Heavysege, Winter Skies

    I spent my evenings photographing the stars and exploring the landscape under the light of the moon. My body began to adapt to the natural rhythm of the night, going to bed with the setting sun and waking up to the morning light. Our reliance on artificial lighting is so strong that the loss of it seemed very strange at first; making do with only the weak beam from my head torch and the reassuring glow from the campfire forced me out of my comfort zone. Fear of the dark is entrenched in our culture but night is as much a part of our lives as day and instructs its own conditions for us to comply with, we need not fear the night, but rather collaborate with it for our mutual benefit.

    Historically, the stars and the night sky have played a large role in our lives; the night sky is ingrained in human culture, it is the universal heritage we share with millions of people across the globe. I find it upsetting that, as increasing numbers of people move to the city, we could lose our historic connection with the night sky, a connection which has guided, inspired and astonished. As we begin to understand the extent to which light pollution is having a detrimental effect on our bodies and minds, we must come up with more creative ways to use light in our environment. I am excited to take forward everything that I have learned and incorporate it into my designs, helping to build a healthier future for us and for our night sky.


    I am indebted to the Landscape Institute for the wonderful opportunity they gave me to travel to another country and investigate a topic I am passionate about. I would like to thank Toby Lewis and Annie Galliliand for giving up their time to talk to me and for inspiring me further. I would also like to thank everyone who helped to make the trip a reality. The Student Travel Award is a brilliant initiative and I would implore all landscape students to apply.


    1. Great to read this Ruth. An inspirationally written piece, which highlights some of the science about the effect of light on quality of life, whilst placing this both in a broader context regarding the shared heritage the night sky presents and more specific one, for lighting design. Good to see the photos also, which paint the picture, Best wishes Josh

    2. What a brilliant read and fascinating analysis of our impact on environmental light amplification. The pictures emphasise the points raised in your ‘thought piece’. Great work Ruth

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