When you think of erosion, it's usually with reference to the land.
Ice, wind, and water erode landscapes over millennia. Whole mountain ranges, given time, are ground to mere sand and dust. It was surprising then, and rather disturbing to hear Dr. Maru Correa-Cano of Exeter University, talk about human activity eroding natural darkness. Dr. Correa-Cano gave an excellent if disturbing talk recently for St. Agnes Gardening Club. She detailed the extent and effects of light pollution on flora, fauna and humans.
I have been aware of light pollution since, as a child, I asked my Dad, "Why is the sky over there orange?" It was way after sunset and even at that age, I knew intuitively that dawn was a sleep away and, in any case, the sun did not rise in the north. What I saw was the glow of low-pressure sodium street lighting, billowing up from the nearest big town. The sprawl of Redditch, newly expanded with its countless estates, service roads, and associated roundabouts seemed suddenly to be at the parish boundary. Growing up in rural Worcestershire I had learned to be somewhat suspicious of all things urban. For the most part, certainly according to the senses of this small child, towns were noisy, smelly, unsettlingly busy and boring. The latter because they invariably involved irritable parents, queues and things I wasn't allowed to have. Perhaps this is why I viewed the orange glow of the conurbation with more than a little fear and trepidation. The town was the beast in the north, coming to lay waste to our village.
If I'd be capable of voicing my infantile concerns then, perhaps the trope, from the mouths of babes, would be fitting here. Perhaps if, 40+ years ago, I had cried out, "I'm afraid of the light", I might have been offering a warning to planners and safety regulators everywhere. "Stop! You are eroding the darkness. The precious darkness that holds up the stars and tells the life of day to rest while the bats and beetles do what they must, in darkness."
Now, with our nights turned to artificial day (countries like the Netherlands are 100% light-polluted) and our eyes incessantly bombarded by short-wavelength light from screens, we should really be afraid. Did you know that a single flash of light in the night can radically change the flowering behaviour of a plant? Or that some creatures of the night are being squeezed into ever-narrowing corridors of darkness in their search for food and habitat. If nature is not your concern then how about a bit of good old anthropocentrism? Scientists are learning more and more about the importance of darkness to our sleep patterns, our digestive systems, and even our immune systems. Security light waking you up at night? It might be doing you more harm than those bad guys you imagine hiding in the shadows!
You can find out more about the work of Dr. Maru Correa-Cano here.