The Warrumbungle National Park in western New South Wales has become Australia’s first Dark Sky Park. Now Dr Kellie Pendoley, an environmental scientist and owner of Pendoley Environmental (a marine conservation biology consultancy) is advocating for Western Australia’s Karijini National Park to become the second. As Australia takes its first steps into a darker future it’s worth asking: what is all the fuss about? Why do dark skies matter?
Here are a few reasons worth knowing about:
Wildlife on Light
Morning songbirds whistling a tune into the night, blackbirds developing without reproductive organs and frogs suddenly turning their backs on mating: these are just some of the documented effects of artificial light on wildlife.
Nocturnal predators rely on the cover of darkness to pursue their quarries; nocturnal prey relies on dark for cover. Birds that migrate or hunt at night are accustomed to doing this by moon and starlight. Changes in the distribution and use of artificial light are fundamentally shifting the habits and hormones of wildlife in ways we don’t completely understand yet.
In Western Australia, not far from Dr Pendoley’s proposed Dark Sky Park, researchers have been looking into the impact of artificial light on green turtle hatchlings.
In order to survive, green turtles must relocate from their nests to the sea shortly after hatching, usually at night. They rely on vision, finding the ocean by moving towards brightness. Traditionally this was effective, as beaches tend to slope down towards the sea, which reflects celestial light and shines in the darkness. By contrast, the rising horizon would have yielded the deep blackness of dunes and forest.
Growth of human settlements near turtle nesting beaches has resulted in increased artificial light on land, which attracts and confuses hatchlings. Disoriented and lost in the human realm, they are vulnerable to exhaustion, dehydration, vehicles and other threats.
Researchers have found that light also causes disorientation once turtles are in the water, drawing them back to the coast and preventing them from seeking deeper waters, where they are safer from predators.
The lights we use have an energy cost, and a lot of light goes to waste. Just think of the plume of white light pouring skyward from a football stadium. Or the light streaming from each individual city office illuminated through the night.
When it comes to thinking about waste, it is far easier to conceptualise a tonne of hard rubbish at a tip than 30 terawatt-hours of energy. However, the energy wasted by light that shines where or when it’s not needed has been estimated at $3.3 billion and 21 million tons of carbon dioxide per year in the United States alone.
According to the International Dark-Sky Association:
“Quality lighting design reduces energy use and therefore energy dependence. It also reduces carbon emissions, saves money and allows us to enjoy the night sky”.
We can use light in an environmentally responsible way by making conscious lighting decisions that maximise efficiency and minimise waste. The IDA suggests dimmers, timers and motion-sensors to reduce the amount of light you use. You can also install outdoor lighting with shields to contain the light and direct it light downwards, where it is needed, rather than into the sky.
Without the darkness of the night many of our most cherished cultural icons would never have been created. Think: Vincent Van Gogh’s Starry Night and Don McLean’s Vincent (Starry Starry Night). And The Raven by Edgar Allen Poe simply would not be the same without the all-pervading sense of darkness that permeates the poem.
Astronomers need a dark sky free from reflected light to see into the universe.
Recent research into the effects of artificial light on human health confirm that human health is intimately linked with the natural rhythms of the earth.
Our sleep-wake cycles are determined by our circadian rhythms, which respond to the cycles of light and dark, day and night. Research has shown that exposure to artificial light, particularly in the evening, can interfere with the body’s secretion of melatonin, a hormone responsible for circadian rhythms.
In particular, blue light (the short-wave light emitted by computer screens, smart phones and eco-friendly LED lights) is a powerful melatonin suppressor, making it difficult to fall into a deep healing sleep (or sometimes, sleep at all).
Quality sleep is essential to good health, and blue light has been indirectly linked to cancer, diabetes, heart disease, and obesity.
Fortunately, there are a few ways you can reduce the blue light in your life (without abolishing screens completely.
There are some great apps like f.lux, which you can install on your computer, tablet or phone to automatically shift the wavelength of light from blue to red as the evening progresses. I have this on my computer and it’s great.
iPhones also have an option in Settings under Display and Brightness, called Night Shift. This also increases the warmth of your screen light at a designated time each day.
The third option is to buy a pair of glasses that block light at the blue end of the spectrum to use at night. I haven’t seen or used them but I’ve heard they’re good.
According to Fabio Falchi from the Light Pollution Science and Technology Institute in Thiene, Italy, 83 per cent of the world’s population experiences some form of light pollution. In certain parts of the world, like Europe and North America, up to 99% of the population is affected. In some cities, such as Singapore and Hong Kong, no one can escape the spectre of a glowing night sky.
Do we have an obligation to preserve the dark night sky – an increasingly limited resource – for future generations? Is there an intrinsic value to the night sky that makes it inherently worth protecting? If so, have we moved so far from this natural state that institutionalised protection is the only option?
Who knows? But I think they might be onto something here.