When viewing the night sky, most of us feel an intimate connection to the universe. Yet starry skies and moonlit nights have become increasingly rare for city-dwellers today. Given the harm that too much light at night is inflicting on human beings and ecosystems, it is time to reconsider our relationship to the ‘nocturnal side’ of our lives and our culture.
By Paul Bogard, a writer and assistant professor of English at James Madison University in Harrisonburg, Virginia, USA
“If the stars should appear one night in a thousand years, how would men believe and adore; and preserve for many generations the remembrance of the city of God which had been shown!” − Ralph Waldo Emerson (1836)
The sight is almost impossible now for most of us to imagine: the natural lights of the night sky spread shimmering above, the low pulse of a reddish moon setting in the west, stars from one horizon to the other dancing white with shades of orange and blue, and green and gold. It is a sight that for all of human history has inspired painters, writers, musicians, poets, storytellers, philosophers, scientists and dreamers. It is a sight that has forever helped define what it means to be human. And it is a sight that, thanks to light pollution (our overuse and misuse of artificial light at night), we have largely lost.
I have been lucky. I grew up in Minnesota, and my family has a cabin near a lake in the northern part of the state. All my life, for days or weeks at a time, I have visited this cabin and known real, natural night. I mean
In researching my book, The End of the Night, I travelled to places such as the Sahara Desert in Morocco and Death Valley in California, to witness night skies so plush they seemed almost unreal. I am convinced that the natural lights of a starry sky and moonlight remain vitally important to our modern culture. With its ability to awe and amaze, to draw out our instincts to imagine and contemplate, the night with its natural lights is like a faithful friend, always there, awaiting our return, its power to shape our dreams and beliefs and myths as strong as ever − if only we would remember.
Photo: Adam Mørk
An ever brighter planet
Of course, we live in a time so different from Emerson’s. Because of artificial light, we no longer know natural night. Satellite views of Earth after dark show vast areas of North America, Europe, the Middle East and Asia saturated with electric light. As cities and towns grow ever brighter, even rural areas have lost much of their natural night. Sadly, almost nowhere in our world is getting darker, and almost everywhere else is growing brighter. We have taken what was once one of the most common of human experiences − walking outside and coming face to face with the universe − and made it one of the
But we are foolish if we think that light pollution is only a problem for people who love the stars. For example, experts estimate that more than $100 billion (US) is wasted worldwide each year on light pollution. Human physical health is endangered, as are the ecosystems on which we rely. Perhaps most surprising, our heavy use of artificial light actually reduces our safety and security.
The good news? Through our lighting designs and the designs of our buildings, the magic of the night can be returned. We can enjoy the benefits of artificial light without sacrificing the natural light that has long been half our lives. Watch the video to learn more about why we need both natural light and darkness at night for greater health:
Light at night – a threat to human health?
When it comes to light at night, we live in a dynamic age. More and more cities are replacing their electric lighting with LEDs (light emitting diodes). But in the long run, these new lights may actually make things worse because they contain high levels of what is called “blue-rich white light. ” This is the worst kind of light for humans and other creatures to be exposed to at night, as blue wavelengths tell our bodies to ‘wake up,’ and confuse our circadian rhythm, the 24-hour internal rhythm that orchestrates our body’s physical health. A good analogy is to think of our body as an orchestra with each of our organs a musical instrument and our circadian rhythm the conductor. If the conductor is confused, the whole orchestra will be affected.
Second, exposure to artificial light at night contributes to sleep disorders. In the 21st century, more and more people, especially those living in cities, are reporting problems with getting enough sleep or enough good sleep. This lack of sleep is contributing to making many of us sick. Sleep researchers see a strong relationship between ‘long light’ − the increased amount of artificial light in our lives − and ‘short sleep,’ the reduced amount and quality of sleep. Researchers have linked a lack of sleep with an increased risk
Third, and perhaps most troubling, scientists have discovered a link between artificial light at night and an increased risk for breast and prostate cancer. It turns out that we produce the hormone melatonin only in darkness − many call it “the darkness hormone”− and that exposure to artificial light at night impedes its production. Researchers have found that a lack of melatonin in the bloodstream increases the risk that cancers may develop, or develop further. When so many other things in our modern lives increase our risk of cancer, why would we want to add unnecessarily to those risks by exposing ourselves to artificial light at night?
Photo: Daniel Blaufuks
Light pollution is also harming our environment. Some 30 per cent of vertebrate
A few examples of these consequences include impacts to birds, sea turtles and insects. Most birds actually migrate at night, and light pollution confuses them and draws them into danger. Birds collide with lights, circle lights until they die of exhaustion, or are drawn into cities and collide with buildings. Similarly, sea turtles have evolved over hundreds of millions of years to hatch on beaches at night and to crawl toward the brightest light on the horizon.
For hundreds of millions of years, the brightest lights were the natural lights of the moon and stars over the ocean, but now the brightest lights are often the hotels and streetlights—and so the baby turtles crawl away from the ocean and to their death. Finally, lights draw insects to their deaths in huge numbers. A new light set in a previously dark area draws insects toward it, and in so doing eliminates them from the ecosystem. Because so many other species rely on insects as food, when the insects die the entire food chain is harmed. We are only beginning to understand how damaging light pollution is for the environment, but one thing is for certain: life on earth evolved with bright days and dark nights, and every living thing needs darkness for optimal health.