Last night was the winter solstice. I was camping in the forest in Ireland, in an area of gold tier dark sky reserve. It is one of few places left in the western world free from light pollution.
It was still and silent as the sun dropped, bats were ducking and diving over my head. Watching them I had a lot of questions. Now I am back in the warmth of my house, I can look up some answers. Evidence suggests light pollution may be having a large impact on our ecosystem. Some species of bat show increased activity in areas of artificial light, others may never leave their roosts at all with extended light periods. The Common Pipistrelle is seen in greater volumes in areas of artificial light. This may be because more hunting opportunities are provided where insects are attracted to the light. It might be beneficial for this species of bat, but it is not a positive effect for the insects or other animals which feed on them. Similarly, light pollution can affect migratory birds. Street lights draw them into the city, but sadly on their arrival they are met with a lack of natural habitat, vehicle collisions and domestic cats.
Artificial light can also create problems for sea turtles. Hatchlings rely on the night sky to navigate from their eggs to the sea. Tiny turtles are often found travelling in the wrong direction entirely, and with limited time to reach the water, this can lead to grave consequences. It appears our wildlife has not yet adapted to the changes we have made to their environment. Surprisingly, as a danger to some of our most highly protected species, light pollution is rarely on the agenda of our wildlife protection agencies. Satellite observations show that light pollution is increasing at a rate of 2% a year. The skies of Hong Kong are 1200 times brighter than they should be, and 83% of the world’s population now lives under polluted skies. In the Netherlands, there are towns using infrared street lights, but the cheapest and simplest solution is to just turn the lights off. Studies show no changes in crime rates, and using less electricity means wasting less energy.
Last night, sitting in my tent, all I could see was black. My surroundings brimmed with the forces of the imaginary. How much do we really know about light pollution? I thought. What don’t we know yet? In a world where the destruction of our wildlife is widespread, light pollution’s role is rarely questioned. I’m not going to insist that you turn your lights off, but I would encourage further research and discussion.
To see a satellite map of street lighting, click here.
About the author
David Molloy is a photographer, writer and researcher. His work attempts to make sense of the world, with concern for the future. This year he has exhibited at the Museum of London and the National Gallery of Ireland.
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