Scientists describe cultural loss of unprecedented magnitude as global atlas reveals extent of light pollution in the worlds skies
It has inspired astronomers, artists, musicians and poets but the Milky Way could become a distant memory for much of humanity, a new global atlas of light pollution suggests.
The study reveals that 60% of Europeans and almost 80% of North Americans cannot see the glowing band of our galaxy because of the effects of artificial lighting, while it is imperceptible to the entire populations of Singapore, Kuwait and Malta.
Overall, the Milky Way is no longer visible to more than one third of the worlds population.
Lead author Fabio Falchi from the Light Pollution Science and Technology Institute in Italy said the situation was a cultural loss of unprecedented magnitude.
Chris Elvidge of the US National Oceanic and Atmospheric Administration and a co-author of the study, added that the times he has seen the Milky Way have been magical experiences.
Through our technology weve cut off that possibility for large numbers of people for multiple generations now, he said. Weve lost something – but how do we place value on it?
Described by John Milton as a broad and ample road whose dust is gold, and pavement stars, the Milky Way is so obscured by the effects of modern lighting that it is no longer visible to 77% of the UK population, with the galaxy masked from view across nearly 14% of the country, including regions stretching from London to Liverpool and Leeds.
Further afield, areas around the cities of Hong Kong, Beijing and a large stretch of the East Coast of America are among those where a glimpse of the galactic band is out of the question – a situation also found across much of Qatar, the Netherlands and Israel. In Belgium, it cannot be seen in 51% of the country.
Humanity has enveloped our planet in a luminous fog that prevents most of Earths population from having the opportunity to observe our galaxy, the authors write.
Published in the journal Science Advances by an international team of scientists, the research is based on data collected from space by the Suomi National Polar-orbiting Partnership satellite, together with computer models of sky luminescence and professional and citizen science measurements of sky brightness taken from the ground.
The resulting global atlas reveals that large swaths of humanity experience light pollution, including more than 99% of people living in the US and the European Union. People living near Paris would have to travel 900km to areas as such central Scotland, Corsica or central Spain to find a region with night skies almost unpolluted by light, the authors add.
By contrast, Central African Republic and Madagascar are among the countries least affected by light pollution, with nearly the entirety of Greenland boasting pristine skies.
Until the advent of night-time lighting became really prominent in the 19th and 20th centuries, everybody would have been familiar with the Milky Way, said Marek Kukula, public astronomer at the Royal Observatory in Greenwich, who was not involved in the study. We see it in mythology about the sky, in all cultures around the world. It is one of the obvious components of the sky along with the stars, the planets and the moon.
When light from our streetlamps, homes and illuminations is thrown up into the sky it bounces off particles and moisture droplets in the atmosphere and is scattered, resulting in artificial sky glow – one of the key factors contributing to light pollution. The upshot is that spectacles like the Milky Way can become obscured from view.
The night sky is part of our natural heritage. It is beautiful, it is awe-inspiring and being able to see it is a way for us to connect to the wider universe and understand our place in the natural world, said Kukula. If we lose that it is a shame because we have lost that direct connection with something much bigger than us and something that is very beautiful.
The situation could become worse. According to the new study, if all sodium lights are replaced with cool white LED lighting, artificial sky brightness seen across Europe could more than double as a result of the increase in blue-light emission.
And it isnt only our view of the night sky that is affected by light pollution. There are also biological consequences, not only on birds and insects and mammals, but also even on humans, said Elvidge, pointing out that the light pollution can disrupt the natural behaviour of animals and has raised a number of human health concerns.
It isnt all doom and gloom. Despite the Milky Way being masked from view in many cities across the UK there are still regions of the country where it is possible to get a good view of the night sky. There are various dark sky parks and reserves in the UK which have been internationally certified by the International Dark Sky Association to have low levels of light pollution – places like Galloway Forest Park, said Kukula, adding that various online tools can help to direct stargazers to the right part of the sky.
But the authors of the new study say more needs to be done to tackle the issue of light pollution. Among possible measures, says Elvidge, are the use of more shielded street lighting, motion-activated lights and cut-off times for illuminating buildings.
Kukula agrees, It will reduce our electricity bills, it will reduce our carbon footprint, it wont affect the lighting that we have on the streets, he said. And it will allow us to see more of the wonders of the night sky.
Generations to come will never see that beauty
We are here on planet Earth but we live in a huge cosmos, and its one of the things that links us to our position in the universe. And so it is wonderful to see it. I think by looking up at the stars we have endeavoured to do so many things, weve sent probes to Pluto and beyond, and if we lose contact with that I think we lose some of our ability to dream and to aspire. It starts with the Milky Way but where will it end?
I spent a wonderful six months working at a telescope in Chile, at the Gemini telescope, and there we could actually see [the Milky Way] – it did look like a path across the sky. It has inspired songs, it has inspired people to great endeavours and so I think the more light pollution there is the more we miss out on that, and the generations to come will never see that beauty.
Maggie Aderin-Pocock, space scientist and presenter of the Sky at Night
I am perhaps more inspired by the Milky Way than any artist who has ever lived
For me the Milky Way has been an unfailing source of inspiration and wonder, as basic component of my identity as the fact that I live on Earth in our Solar System.
I have been a passionate evangelist for the galaxy, and am perhaps more inspired by the Milky Way than any artist who has ever lived.
I deplore the barriers we have erected that block the view for most of Earths people. Nothing can clear the mind, elevate the soul, or inspire curiosity more than the Milky Way.
Jon Lomberg, artist and principal artistic collaborator of astronomer Carl Sagan
Its important that its not just astronomers who care about this
The night sky is the most universally-shared part of our environment. Its been gazed and wondered at, throughout history, by people in all parts of the world. Its indeed a sad deprivation that many young people have never seen a clear starry sky. And its important that its not just astronomers who care about this.
Im not an ornithologist, but Id feel deprived if songbirds disappeared from my garden. Likewise, there would surely be widespread sadness if light pollution screened out our celestial environment from ever more of us.
Lord Martin Rees, astronomer royal
The Milky Way is our link to the Other
The Milky Way is our link to the Other: to the lost civilisations out there in the galaxy, so far away and so profligate that they appear not as stars, but as a single brush stroke of watery light. When we lose the Milky Way, we sever the umbilical cord that connects us to the wider universe.
Ben Miller, actor, comedian and author
We, in our ceaseless dash to make money and cover the world with concrete, have lost this priceless treasure
Its not just the Milky Way [people] cant see. Who in the 21st Century has ever seen the Zodiacal Light – that beautiful cone of dusty light that can even outshine the Milky Way, a thrill to see if you are lucky enough to have dark skies where you live. And probably about 10,000 stars that the three Wise Men on their way to Bethlehem would have been able to see are all invisible to us in the cities, where we are swamped by mainly unnecessary stray light. From my roof in Kensington on a clear night I can see roughly 30 stars – its a tragedy, really. Along with all the other excesses of what we call civilisation, our first-hand awareness of the cosmos has been forgotten.
We are so fortunate to be living on a planet that gives us a view, not only of our own Solar System companions: the planets, comets, etc – but also of countless stars in our own Milky Way Galaxy. Because of this weve been able make the foundations of cosmology, discovering the very nature of the vast universe around us. From our position out on a spiral arm of the Galaxy, we see both inwards towards the centre of the Galaxy and outwards towards its edge. The billions of stars in the Galactic plane show up as a milky light which has enchanted people from the dawn of history. But we, in our ceaseless dash to make money and cover the world with concrete, have lost this priceless treasure. Along with almost all our wildlife, our contact with Nature, and our humanity.
Brian May, astrophysicist and lead guitarist of Queen
We should act to protect our ability to enjoy the universe
The Milky Way evokes a feeling of awe when I see it. It always has and it always will. This is partly because it is rare to see now due to light pollution. Its analogous to spotting a rare bird in your back garden. But I have many memories of seeing this band of hazy light from the dark skies of my village when I was younger. To be able to see the collective light from the stars making up our own galaxy gives a tantalising sense of the enormity of our universe and the structures within it. That so few people are now able to see now the Milky Way is a great loss. We are forcing ourselves to look inward and not outward. And just as we bemoan the loss of our countryside we should act to protect our ability to enjoy the universe. If we dont, its inspirational value will be untapped and a site of scientific interest will be rendered accessible only using professional telescopes on mountains or on spacecraft.
Lucie Green, Professor of Physics at University College, London and presenter of the Sky at Night