Let There Be Light
Artificial light is everywhere all the time in our towns and cities, and is increasingly intrusive in the countryside. We don't give it much thought, except, ironically when it is not there. It is though very different for wildlife: the impact of so much light when the world should be dark is considerable. From robins who sing all night instead of resting, to insects being snapped up by bats who have learnt to hunt around lights, and moths fluttering around windows, light pollution affects behaviour and increases risks.
I remember some years ago appearing at a public enquiry into whether or not a business park should be built somewhere in Warwickshire. In the middle of someone's evidence the lawyer I was with suddenly hissed 'What effect does 24 hour lighting have on wildlife?' I was at a loss to give him anything more than a general answer.
I also recall visiting a new town development in Florida which was designed to be as environmentally-friendly as possible. One of its features was 'dark skies' street lighting. This consisted of fairly standard lights fitted with large shades which ensured that whilst the street below was well lit none of the light escaped upwards or to the sides. Not wholly effective because of course the roads and cars reflected some light, but better than nothing.
Help is now at hand for hapless conservationists needing to answer the lawyer's question. Earlier this year Buglife (the Invertebrate Conservation Trust) published a report (A Review of the Impact of Artificial Light on Invertebrates) on the impacts of light on insects. Some of the issues raised may be surprising. Street lighting is an obvious problem, but how about solar panels and plastic sheeting? Their surfaces polarise light (that is break it into its different components, as with a rainbow). For most of the planet's history only water surfaces did this and many creatures evolved to respond accordingly. Now many insects lay their eggs on and around these artificial surfaces because they are fooled into treating them as if they are water.
The Review suggests a number of things which might help: switching off external lights in the middle of the night, avoiding the use of ultra-violet emitting light bulbs, taking more account of sensitive areas close to nature reserves and ponds, and doing more to provide dark skies locations. The most obvious 'Lighting should be kept to a functional minimum in all areas' should be both easy and welcome - after all every light that is shining is costing somebody money.
The full report is available to download from Buglife's website (www.buglife.org.uk). Follow the links to News and News Archive.