Talman Madsen

Let there be night

At no other point in human history has the planet been this bright after the sun sets. But artificial lights affect us, and the environment around us, in subtle ways… What happens to us when there’s too much light in the night?

Written by       Photographed by Talman Madsen

A panorama shot from Nugget Point Lighthouse reveals the massive aurora australis that delighted astrophotographers and skywatchers around the world on September 9, 2017. The aurora registered over Kp8 on the Kp-index, a measurement of geomagnetic activity that ranges from 0 (no activity) to 9 (extreme activity).

I was awake for most of the three months I spent at Scott Base in 2008. It was summer, so Antarctica did not have a night, and I suffered. The light, reflecting off the snow and ice outside, was so bright you could almost feel it. Each night, after closing my bunk’s shutters against the sun, I was tormented by hard slits of brightness that shone through the cracks and slipped easily around any form of eye mask.

Often, I gave up on sleep and roamed the halls of the base instead, each window I passed a bright square of white. The only concession to the night was a lower sun, which skimmed the horizon and washed the snow and sky with a slightly more pastel hue. My eyes felt permanently gritty, and I experienced overwhelming anxiety—not helpful when I was there on a journalism scholarship as a brand-new graduate, struggling to adjust to the expectations and rigours of my new career.

The laundry drying room was my only respite. It was a dark, warm, windowless locker, and I would sit down inside it until the darkness seeped in and my brain unclenched, my eyes and brow finally relaxing.

This wasn’t an uncommon situation for visiting scientists at Scott Base and its American neighbour, McMurdo Station. The 24-hour daylight, as well as the limited window that scientists have on the ice to conduct fieldwork, leads people to cram their nights as well as days with work, and the more experienced warned the newbies to avoid burnout. While I was stepping outside into the bright frozen world at night, I didn’t realise how desperately humans need the dark.

More properly, we need our circadian rhythm to remain steady, triggered only by the sun coming up and the sun going down. Like our ears, which regulate both hearing and balance, our eyes have two functions: vision, and light detection. Light detection is unconscious, and unrelated to vision. Some people who are visually blind can still tell if there is light in the environment or not.

Rod and cone photoreceptor cells in our eyes detect light and synchronise our internal clocks, controlling every process in the body—digestion, sleep, learning, memory, immune function, behaviour and mood.

We need strong light to appear in the morning and fade in the evening for the clocks embedded in each tissue of our body to function as they should.

Experiencing too much light at the wrong time of day—especially blue-wavelength light, which naturally peaks in the early afternoon—interferes with our hormonal cycles, and has been implicated in health problems ranging from depression to cancer. This is because light suppresses production of the hormone melatonin, which is usually released at night and which the body uses to regulate its sleep cycle. Sean Cain, a circadian biologist at Monash University in Melbourne, discovered that each of us differs in our suppression of melatonin, making light sensitivity a potential biomarker of depression. (Cain has replaced all the bulbs in his own house with smart lights that automatically turn orange after dusk.)

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Artificial light emissions are increasing globally: during the second half of the 20th century, the rate of growth was three to six per cent per year. A 2017 study using the first-ever calibrated satellite radiometer estimated that Earth’s artificially lit outdoor area grew by more than two per cent per year between 2012 and 2016.

Eighty per cent of Earth’s land mass now suffers from light pollution, while for 99 per cent of people in Europe and the United States, the night sky is obscured by artificial lighting, according to research by the Light Pollution Science and Technology Institute in Italy.

We are only beginning to understand the ecological and biological impacts of turning night into day. For animals (including us), sunlight, moonlight, and starlight all trigger cues for behaviour such as breeding, migration and hunting.

Predators use light to hunt; prey use darkness for cover. Artificial lights disrupt the nocturnal activity of amphibians including frogs, whose croaking is part of their breeding behaviour. Sea turtles hatch at night on the beach and the hatchlings find their way to the sea by detecting the bright horizon over the ocean; artificial light draws them away. Birds migrate or hunt at night by using moonlight or starlight, and night-time illumination can cause them to collide with buildings or confuse seasonal cues to migrate to hunt, breed, or nest. Nothing on this planet evolved with the artificial light we’ve now created.

Night becomes day as bright blue-white LEDs light up Christchurch’s Hagley Park. LEDs are more similar to daylight in colour temperature. This has been found to suppress the hormone melatonin, affecting our circadian rhythms and having adverse affects on human health and mood.

There has been little research into the effect of artificial light on the natural environment in New Zealand, despite the host of native species that are nocturnal.

Steve Butler, director of the Royal Astronomical Society of New Zealand Dark Skies Group, says this is beginning to change.

“The Aoraki Mackenzie Dark Sky Reserve has put it into the public arena; there has been a lot of success down there,” he says. “My goal originally was just looking after astronomy but it’s become a much wider issue than that now.”

Light pollution has been found to be a driver of insect declines—“a potent evolutionary trap”, according to one international paper. The authors—including University of Waikato researcher Bridgette Farnworth—wrote that “Street lamps cause some species to retreat, while others for unclear reasons perch beneath them, stunned, or circle around them endlessly until claimed by injury, exhaustion, or predation.”


A 2018 study by Farnworth showed that artificial light on Sanctuary Mountain Maungatautari reduced the number of observations of cave and tree wētā by 72 per cent and 88 per cent respectively. She pointed out that although there have been proposals to use artificial light to deter predators such as mice and ship rats at ecologically valuable sites, light may adversely affect native species, and little is known about invertebrate responses to these altered lighting regimes.

It also appears they’re more sensitive to some wavelengths than others. One New Zealand study by Scion researchers discovered that 48 per cent more flying insects were attracted by modern white LEDs than by traditional orange high-pressure sodium streetlights—especially moths, butterflies and flies.

Auckland astronomer Nalayini Davies is the driving force behind dark-sky enthusiasts around the country who are trying to preserve prehistoric night in their own areas, with a view to New Zealand potentially becoming the world’s first dark-sky nation.

“Dark sky has crept into New Zealand’s vocabulary now,” says Davies. She and Dark Sky Waiheke Island advocates (she and husband Gareth have a home on the island) have successfully lobbied to have some of their streetlights changed from 4000K to 3000K LEDs, which produce a warmer—more orange—light with a better reflector hood to avoid light pollution.

Midnight on Cashel Street might feel like midday—brilliant LEDs cast shadows like the sun, contrasted with the warmer colour temperature of sodium lamps in the distance. We have rapidly modified our nocturnal urban landscapes, increasing artificial light emissions up to six per cent a year, every year since the middle of last century. We are in love with light, but it doesn’t agree with our physiology.
The gannet colony on Mahuki Island, off the coast of Great Barrier Island/Aotea, has a view of Little Barrier Island and the loom of settlements further north. This photo was taken during nautical twilight, just after dusk at 8.30pm in mid-November. Whangarei, Auckland and the Whangaparaoa Peninsula all glow on the horizon. Great Barrier Island, one of the world’s only accredited Dark-Sky Sanctuaries, is one of the few places where it’s possible to see a primal night sky. There is increasing evidence to suggest that birds and other species are affected by light pollution, altering navigation, behaviour, and more alarmingly, breeding success.

Lightwise Guild spokeswoman Kyra Xavia’s journey into darkness began when new white floodlights were installed at the rugby ground in Waikouaiti, an East Otago seaside town.

She says the lights were unshielded, “blindingly bright and extremely powerful”.

“They totally ruined the darkness at the beach and lagoon through wintertime, which is when we have superb stargazing conditions,” she says. “It hadn’t gone through any public notification because the decision makers felt it had minimal impact. If this is happening in small rural towns in New Zealand, what is going to happen elsewhere if we don’t protect our night skies?”

The sportsground lights are still there, but Xavia is now a delegate for the International Dark-Sky Association (IDA) and a Dark Skies Ambassador for the International Astronomical Union.


At least a dozen community groups are working towards IDA accreditation for their own region. They will join two of the world’s only island Dark Sky Sanctuaries, Great Barrier Island and Stewart Island, and one of the best Dark Sky Reserves in the world at Aoraki Mackenzie, which includes Tekapō (which should more properly be known by its Ngāi Tahu name Takapō, meaning ‘to leave in haste at night’.)

With its proximity to light-polluted Auckland, Waiheke Island may not seem like a prime dark-sky spot, but advocates say the eastern side of the island is nearly as dark as Great Barrier, thanks to the geography of the hills that block out Auckland’s blaze.

Kim Wesney, a nurse and artist, is involved in Waiheke’s bid to become dark sky accredited. As a child, she recalls climbing her backyard rotary clothesline at night, wanting to get closer to the sky. That feeling of childhood wonder at the universe—emphasised by years spent watching the sunrise and sunset during shift work—powers her through dark-sky advocacy today.

“In the early 80s, when I came over [to Waiheke], they were doing some star parties at Trig Hill and it was just gorgeous,” she says. “There were a lot fewer houses then and I fell in love with that ridge. It was stunning up there; there was a beautiful east-west path across the sky, and fewer trees then. You could see Auckland twinkling in the west and it was dark in the east with a beautiful open sky.”

The University of Canterbury Mount John Observatory in Tekapō has become a popular destination for stargazing, and the town is racing to catch up with its flood of visitors. In the middle of the Aoraki Mackenzie Dark Sky Reserve—recognised by the International Dark-Sky Association—the area is credited with helping to popularise the dark-sky movement in New Zealand. Spreading the dark-sky tourism load to other centres around New Zealand would help other regions take advantage of their natural night.

It’s important, says Davies, to build and capture this local drive towards dark-sky preservation rather than imposing it on people. Once new lights are installed, it’s hard to get rid of them, so everyone needs to be onboard.

“We all need light now to live; it’s an important utility for us,” she says. “We are not saying don’t have lights. We are saying don’t have unnecessary lights.”

Different places around New Zealand are considering what level of accreditation they can achieve within their communities (see sidebar). Wairarapa, for example, gained $100,000 this year from the government’s Provincial Growth Fund to support its application for a gold-standard Dark Sky Reserve (similar to the 4300-square-kilometre Aoraki Mackenzie) over the southeastern corner of the lower North Island. At 6000 square kilometres, the Wairarapa reserve would be the biggest in New Zealand. The New Zealand Transport Agency has promised it will change the highway lights there to a lower temperature. If successful, it will become one of four internationally recognised dark-sky locations in New Zealand and one of just a handful in the world.

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Recently, I did a little home experiment with turning off artificial lights—or, rather, simply not turning them on as the day darkened, and not using any blue-light-emitting screens in the evening. My husband was onboard, but we quickly learned that you can’t undergo such a significant change in the use of those precious three or four hours before bed in the dusk without being forced to address a lot of other habits in life.

I discovered that closely managing those evening hours dramatically changed the way I felt about everything that had happened that day, and my sleep, and the day following.

Campers enjoy a night under the star-spangled banner of the Milky Way galaxy in the Bay of Plenty. Intrepid trips under unspoiled skies tick the boxes of travellers wanting increasingly authentic experiences in nature.

In fact, it reminded me of mid-January 2009. When I left Scott Base and got home to Christchurch, I stayed for my first night in a room at an airport hotel. In the evening, I stood outside, eagerly awaiting my first darkness in 13 weeks.

When it came, I remember feeling like a blanket was being laid over me. It was the sweetest balm, flooded with everything I hadn’t realised I’d missed in Antarctica. It had rained and the air was damp. I could smell flowers, and wet fresh grass. I could hear insects. Then the darkness slowly flooded over me and my eyelids felt heavy and I closed my eyes in welcome.

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