In December 2013 I wrote a piece in KCW Today called Night Blight, about light pollution in the UK. Given the results of recent research into this problem, the question is are we succeeding? According to Brett Seymoure, a behavioural ecologist at Washington university in St Louis a leading member of the team studying the rapid decline of insect populations, the answer is probably not. Of course, what scientists refer to as an “insect apocalypse”, is due to a number of factors, there is habitat loss, overuse of pesticides, invasive species, and climate change. Insect populations particularly moths and gloworms are misled by the stray light and fly in endless spirals, or for natural night flying insects they stop flying altogether presumably confused by what must seem endless daylight.
The day/night behaviour, feeding and mating patterns of birds, bats, nocturnal animals and countless other species are disturbed and millions killed by this unnecessary light. However, one cause we all individually have some control over and a voice to be heard with, is that of light pollution. As Seymoure says light pollution was the easiest of all the threats to eliminate, “Once you turn off a light, it’s gone, plus you don’t have to go and clean up, like you do with most other pollutants.” In February this year, the Campaign to protect Rural England (CPRE) enlisted members of the public to assist in a star count, using the well-known asterism of the Constellation of Orion. How many naked eye stars could they see in the box formed by the four stars Betelgeuse, Bellatrix, Rigel and Saiph? The results were disappointing and nothing much had changed since the last star count in 2014. This year 57% of respondents counted fewer than 10 stars visible in Orion, i.e. very badly impacted by light pollution. Only 2% could see 30 or more stars in good dark sky locations and 9% had dark skies and could see between 21 and 30 stars.
Where I have my observatory in E. Sussex, I could see between 15 and 20 but was always aware of the massive loom of light to the north of me, ‘London’ and a similar glow due south, ‘Brighton.’ To be fair councils have tried, there has been a gradual switchover to LED, (light-emitting diode), lights to banish the diffuse orange glow of the old sodium streetlights. They are more energy efficient and therefore cheaper to run. Efforts have been made to shield light better, so it’s all directed downwards where it’s needed. However, the gains are often cancelled out by installing more lights, because they’re cheaper. LEDs may not be the answer after all, as that blueish light is, unlike red light, easily scattered by plants and trees. The atmosphere itself scatters blue light more than red light hence the answer to why the sky is blue during the day, but it can also be just as effective at making carelessly placed LEDs give the sky a blue tint at night. Most of us recognize our climate is changing, especially our younger generation. The cost caused by unnecessary commercial lighting on all night (floodlighting warehouses, supermarkets, churches, carparks, storage centres etc), coupled with our own poorly sited and over lit domestic contributions (garden & domestic security) amount to a staggering £1billion of wastage per year. One 100w bulb left on for 1 year will generate ¼ ton of carbon at the generating station.
The problem is not light itself, but the careless use of it. Unnecessary lights, poorly aimed, poorly designed and poorly sited. Where possible, lights should be switched off between midnight and dawn, others should be dimmed, still others should be replaced by more energy efficient modern designs, illuminating only that which is below the horizontal and with minimal light spill. My love of astronomy came through Night Blight II By Scott Beadle FRAS celestial navigation. Before GPS, LORAN, SATNAV etc. became available to yachtsmen, when I was in deep ocean, only the Sun, Moon, planets and stars would tell me where I was. In deep sea of course, there was no light pollution, but instead this extraordinary light show from above made me feel a most profound connection with the universe itself. Tell your friends and neighbours that their night sky is disappearing, that local government are wasting huge sums of taxpayer’s money lighting up the sky. Tell them how excessive glare can contribute to car accidents and harm nocturnal wildlife. Only sustained and concerted action will bring back the night. “The night sky is one part of our environment we have shared with all cultures in all periods of human history” said astronomer Sir Martin Rees.
Five thousand years ago the Sumerians and Egyptians were mapping the night sky. They marvelled at the ghostly river of light which is the Milky Way, our own galaxy of some 200 billion stars seen from within one of its spiral arms arching across the sky. It sad to report that the world itself is losing that wonderful deep darkness of the night. A 2017 analysis of satellite data shows that artificially illuminated areas of the world are still expanding at 2.2% each year, and getting brighter. Some 83% of the human population lives under light polluted skies. A third of the world’s population can’t see the Milky Way! We should try and regain our night skies, for ourselves, for our children, for our future. I for one don’t want my children and my grandchildren to only experience the Milky Way as something bought in a sweet shop.