*Pic: WikiCommons, Pinnacles Night Sky - Flickr - Joe Parks: Image from here
There is an emerging worldwide awareness of how an ability to view the natural night sky is increasingly being denied to a large proportion of the Earth’s human population. The domes of wasted light that are today cast skyward by our expanding urban areas mean that light pollution is not only an issue where we live, but that it is also increasingly following us even when we visit national parks and other supposedly natural places.
This wasted light is also wasted money, and it also implies waste of the environmental assets that are too often destroyed to produce that energy.
There are both tangible and intangible costs that light pollution imposes on us as individuals and as members of a species that has evolved, biologically and culturally, under night skies (1). There is also increasing awareness of some of the impacts of night-time light pollution on biodiversity (2). The stars are being lost to us and to all who sail with us, but it need not be this way, and it must not stay this way. It is way past time that we terminated our acquiescence to light pollution.
Light and logic
The problem of light pollution is compounded by the way we tend to take the unnecessary wasting of light for granted and sometimes even regard it as a good thing, without thinking through the logic of some of our habitual assumptions.
For example, perhaps there is something primordial in modern humanity’s obsession with artificial light; a throwback to the days when the earliest of our kind sat beneath star-filled nights, huddled for warmth or cooking around fires that also dissuaded predators from approaching, and thus led us into feeling that security lay in surrounding ourselves with light, even long after the beasts that haunted the fears of our ancestors had departed the Earth. For whatever reason, every time we have a local election out trot the candidates muttering simplistic mantras about providing more light to make people safer.
Yes, light can help sometimes, but even leaving aside such basic questions as whether more light truly reduces crime or merely displaces it to somewhere else, have you ever sat by a fire alone in the bush late at night and somehow spooked yourself a bit? As your prehistoric instincts draw you closer to the fire for the apparent security of the light from its flames, that light actually progressively blinds you ever more to the shadows over your shoulder – it would be more logical to actually withdraw from the fire and instead sit in those shadows and watch towards the light and what it illuminates.
So too with putative public safety campaigns that involve increasing illumination of public places. They are always about quantity, never about quality. Bigger is better and bright glaring lights are like a giant re-election advertisement showing your alderman has done what he promised. But glare is not effective light, and it blinds one to any approaching threat rather than illuminating that threat. Moreover, glare causes the pupil of the eye to shrink, making other places now seem darker. Can’t see? Ah! Then we must need some more light then eh?
And so the positive feedback escalates the wasted energy, the environmental harm caused in generating that energy, and often even the safety hazard - bright lights reflecting off a wet road at night are often busy-making enough, without being blinded by lateral glare from streetlights pointing the wrong way, bright lights illuminating someone’s advertising billboard, or narcissistic flood-lighting of someone’s bid for architectural posterity. And excessive light is also costing us the stars under which our ancestors sat. But this need not be the case.
If one suspends a light globe above a point to be lit, then only that light shining within 70 degrees of the ground usefully lights the way. Light directed at 70-90 degrees just dazzles the user. The remainder of the light, 90-180 degrees is simply wasted. The unnecessary energy generation this requires is further exacerbated if light covers diffuse rather than focus the light. Typically, about 80% of the energy that powers an outdoor light is wasted. With effective shielding and direction, this unnecessary cost can be avoided, and less light can become more light.
As far as protecting the night skies is concerned, the critical angles are 90-95 degrees, where light is scattered by aerosols, and from 100-180 degrees. High and low pressure sodium lamps use less energy and emit a spectrum of light more useful for humans, and less harmful to biota, humans included. The commonly used mercury vapour lamps (MVLs) require ~70% more energy than high pressure sodium vapour lamps (HPSVL) and 14% more than low pressure SVLS.
Duration of lighting is also an important consideration. Why leave lights turned on when they are not needed? But how often have you seen your local street lights unnecessarily turned on when it is still daylight? While day-time artificial light doesn’t directly damage the night sky it is still wasteful of the environment damaged to create the energy, and of money. But all sorts of lights are also often left on at night long after everyone has gone to bed and they are no longer needed. Not everyone may like daylight saving time, but we should all be demanding starlight saving time.
Stars and symbols
Since ancient times, people have found meaning in the night skies, which became inextricably linked with everything from legends and folk tales to traditional festivals, mystical astrologers and crop planting. The stars have been fundamental to the evolution of cultures world-wide. In Australia some Aboriginal ceremonies coincided with the full moon. In New Zealand the tides of the universe and journeys of the constellations formed key parts of the education of Maori children, who learnt also of the 36 houses into which the night sky was divided, and who in their later lives used the stars to guide navigation, and to time seasonal planting and food gathering.
For our curious and exploring species the stars became fundamental to navigation and sea-faring. As techniques of time measurement progressed to the use of calendars, and as science became ascendant, astronomy began to figure heavily in much early European exploration and scientific endeavour. In Tasmania we retain some physical artefacts of epic journeys across the globe to observe the transit of Venus, and indeed Cook’s great Antipodean encounters of 1796 occurred after his voyage to Hawaii for the same purpose.
Perhaps the fact that Slovenia is the only member of the Earth’s family of nations to feature a mountain on its flag attests to a connectedness to nature that makes a sensitivity to the celestial something predictable – at any rate, Slovenia appears to have been the first country to take a comprehensive approach to the issue of light pollution, its Decree on Limit Values Due to Light Pollution of Environment (UI Rs 81/2007).
Flags say a lot about the importance we attach to things, and national flags worldwide suggest that many peoples think stars are important. Slovenia is a member of the European Union, whose flag is a circle of stars. Our Australian flag bears claim to our land under the Southern Cross, as does that of our kiwi brethren across the Ditch. China too symbolises its nation with a star, and the USA uses 50 stars, perhaps in the hope that at least one of them might remain dimly visible through the increasingly over-lit and grimy skies that now deny a view of the Milky Way to the majority of the northern hemisphere population.
The natural lights in the heavens have not only anchored us to our lands, but they have also anchored us to our souls. From the Star of David to the Islamic crescent moon, celestial bodies witnessed from the Earth have come to symbolise all that is greater than humanity. How is it then that these temples of the sky can suffer sacrilegious abuse with nary a whisper from people of the faiths?
For example, how can a Christianity for which a star guiding wise men to the birthplace of Jesus is so emblematic, simply stand by silently while the chances of most of the Earth’s population ever again being capable of seeing such a sign are wiped away by the light and air pollution being generated by the ascent of a new trinity of human narcissism, greed and apathy? According to the Book of Genesis God said “Let there be lights in the firmament of the heaven to divide the day from the night; and let them be for signs and for seasons, and for days and for years; and let them be for lights in the firmament of heaven to give light upon the earth. And so it was”. He is said to have separated light from darkness, but kept both – actually destroying darkness was apparently not His idea but is instead something we humans have apparently chosen to do.
But now a large part of the Earth’s population has grown up disconnected from the starry nights that enabled their forefathers to find and know their place in the world, and to develop the humility that flows from the sense of insignificance inevitably gained from gazing into the immensity of the cosmos. Ignored silhouettes on some calendars are now the nearest most people come to any familiarity with the phases of the moon.
It’s not just in the big cities
I have the great joy of living on the slopes of Mt Wellington at Fern Tree in southern Tasmania. My family moved there when I was less than two years old and I grew there until a bushfire in 1967 when our home was destroyed. The land stayed in our family, frequently visited and occasionally camped upon, and since 1983 I have been resident there again, raising my own family in the same place as my Dad would once point out to me the constellations by which he used to navigate aircraft, and from where I saw the first artificial satellite, Russia’s Sputnik, cross the heavens. So in a country in which most families move residence on average every eight years or so, and hence do not see the long term changes in any one place, I have been able to observe the changes at Fern Tree for over half a century. Increasing light pollution has been among the worst of those changes.
When I was a kid there were few lights in our view down the Browns River Valley to D’Entrecasteaux Channel, Bruny Island and the Southern Ocean beyond: we would watch the stars, the dancing aurora australis, or the lightning of storms far out across the Southern Ocean. It was a great joy to return to live once again in Fern Tree in 1983, our beds positioned close to the windows, and we often also slept out on the back deck beneath the spectacular canopy of the night.
The first onslaught against this idyll, which until then had been one of the greatest pleasures of my life, came with the modification of a nearby streetlight such that instead of merely lighting the roadway made sleeping on our back deck no longer tenable. It also reflected light back off the surrounding forest, thus eliminating the star-views from our bedrooms. I asked the Hydro Electric Commission about masking the streetlight and they were happy to comply, subject to Hobart City Council approval. But the HCC officer responsible proved utterly dismissive: she told me that installing shields, even at my own expense, was entirely out of the question because it was against council policy. I was left wondering what manner of process could possibly be involved in developing a policy that seemed to suggest the possums, sugar gliders, potoroos and all our other nocturnal neighbours needed street-lights to find their way around their forest homes. And I wondered too just how many units of electrical energy were being wasted on this grand accomplishment when properly directed lighting of lower intensity would involve lesser cost to ratepayers.
Then there was a second assault on our night-time joy: the dome of wasted upwards-directed light and resulting sky-glow caused by a failure to consider light pollution and energy waste in planning the growth of suburban Kingston. This further faded our stars and auroras, a process which I assume Kingborough ratepayers must be equally happy about paying for, perhaps in the hope of attracting intergalactic aliens who might do business with enterprises owned by local councillors.
And so I came to the conclusion that for every excessively bright idea of a local council lighting bureaucrat there is an extremely dim intellect. A Hobart City Council policy of wasting energy and ratepayers’ money in order to pollute the night sky with light? Energy wasting new suburban expansion still being permitted in Kingborough more than a decade after more advanced local governments such as the McKenzie District Council at Tekapo in New Zealand had commenced legally requiring properly directed and shielded lighting of appropriate intensity and type? And Tekapo is hardly alone in recognising and responding to light pollution, and no longer are measures to protect the night restricted just to local level governments.
As a plaque of light pollution and dirt has formed across the canvas of the cosmos, our doors are closed, our curtains drawn, and our guidance comes instead from the dancing lights of televisions and computers, soap operas and personality news entertainment replacing awe and reflection. Contemplation of where we have come from and what it all means has progressively been reduced to the shallow answer that we have just come home from work which means we must now choose between watching Crime Scene Investigations or Sex and the City. The ageless celestial beacons that have guided humanity on its journey of millennia have been replaced by human “stars”; these momentary human “flashes in the pan” have replaced the shooting stars of the eternal skies and they act out soap operas that do not guide but instead only mislead.
The dancing auroras that have nourished legends now lie forgotten in favour of flickering cathode rays on TV and computer screens. The scales of awe in the human mind have been reduced from thousands of light years to a few centimetres of screen width - that now seems to be the limit of what the once wide-ranging human intellect remains capable of digesting. No longer the magical twinkling of the real stars but instead just the twinkle in the eyes of advertising executives and media barons for whom neat little packages are so much easier to commodify, just as their minions in politics seek to package the complex into 10-second sound bites.
Since even before 1957 when that Sputnik commenced formally erasing the notion of having sovereignty over the stars above one’s homeland, and began instead converting Space into a legal Commons, the emergence of light pollution has seen the opening act of Garret Hardin’s Tragedy of the Commons being acted out in our skies.
Help turn the stars back on!
Considering the energy that we waste in order to pollute the night with un-needed light, turning the stars back on is probably a cheaper option that keeping them switched off. More importantly, the night skies are a wonder that deserves our respect. And those other organisms that have evolved beside us in a natural regime that has involved the light of day and the natural darkness of night also deserve our respect and consideration. They have much at stake but had no vote in our collective human decision to switch off the night.
The night skies are as much the cultural heritage of the human species as they are our collective natural heritage. Treating the mould that has shaped a large part of what we are as humans, as if it were merely some sort of optional extra, is not only to our cost aesthetically and culturally, but in biological terms it is perhaps also to our peril. And so, from holding our local city councillors and bureaucrats to account to ensuring that light pollution is always considered in national park management and making sensible personal decisions about the way we use light around our homes, all our hands should be reaching towards the switch that will turn the stars back on.
(1) Starlight and birthright. TNPA 15: 4-6. http://www.tnpa.asn.au/uploads/7/6/3/9/7639222/tnpa_news_15_email_version.pdf
(2) Artificial light, biota and park planning. TNPA News 16: 6-8. http://www.tnpa.asn.au/uploads/7/6/3/9/7639222/tnpa_news_issue_16_email_version.pdf
*Kevin Kiernan is a sixth generation Tasmanian who has spent most of his life poking around in wilderness areas, mountains and caves on seven continents, in both personal and professional capacities. A geomorphologist by training, he recently retired from the University of Tasmania, where he had researched and taught Conservation Geomorphology and also a unit on the Geography and Environment of Asia. In his earlier life he worked as an environmental campaigner and then as a national park planner, before spending 14 years in the Tasmanian forest practices system. He is currently doing a fairly poor job of attempting to learn to be a retired gentleman.
• Pete Godfrey in Comments: Being a person who has lived for the last 40 years with home generated power, mainly solar for the last 30 years I am appalled by the amount of energy that is wasted on street lighting and in office buildings in the cities. My response to hearing strange noises outside is to go out without a torch and see what the noise is. I find it much more useful to be able to assess the situation from a dark space than to broadcast my presence. When I was younger I used to be scared of the dark, when walking through a forest at night I would feel scared. I found that stopping and looking at the stars returned my sense of place and calm. I still rarely use a torch outside, our eyes are designed to adjust to different light levels and using artificial lighting only destroys this ability.
• Doug Nichols in Comments: Having grown up on a farm, it pleased me more than a little, when I moved in to my house in South Hobart years ago, to discover that the power pole across the street did not have a street light on it. They are on alternate poles and my house is bathed in (relative) darkness, as it were. I rarely put the outside light on either. I prefer, when walking home in the dark, to have the chance to see a few stars and enjoy being in the night. What a stunning experience it must be for a lifelong city dweller to experience a truly dark sky on a moonless night. It’s stunning enough when you know what to expect.