Light Pollution - An Unnecessary Evil


Light Pollution - An Unnecessary Evil

Light Pollution over Melbourne as seen from Kinglake

Light Pollution is an unnecessary evil, a sad result of poor lighting design.

Light Pollution:

  • Spoils the view of the night sky for over 100 km from major cities and renders all but the brightest stars invisible from within the suburbs.
  • Affects human health by brightening the environment in which we sleep.
  • Creates glare, distracting drivers and making it difficult to see at night, particularly in the wet.
  • Significant environmental harm through impacts on wildlife.
  • Wastes energy and increases the cost of providing lighting.

Perry Vlahos from the Astronomical Society of Victoria had a nicely written article in The Age newspaper, 'Let there be less light', which featured my image above. From The Age article:

Because it never really gets dark in cities any more - what we have is an advanced twilight instead of night - the production of melatonin in humans tends to be delayed and suppressed. This compound is normally produced at night only, when our eyes sense it has become dark.
The concern is that melatonin is not only required for regulating sleep, it's an essential precursor for many other important biochemical functions, as well as being a powerful antioxidant that inhibits the growth of some cancers. Recent medical studies indicate there are reliable correlations between excessive light exposure at night, low melatonin levels and the incidence of breast and prostate cancers.

But the article also showed that examples of good lighting are out there, and easy to apply elsewhere:

At a recent Australian lighting summit where I was invited to tell all about light pollution, lighting designers, engineers and representatives from lighting companies received my presentation enthusiastically. Many of them were already talking about ''smart lighting'', and examples of it can be seen throughout Melbourne. It means including full cut-off shielding or baffles on lighting fixtures, preventing light seeping upwards and sideways. Good examples of this can be found along the Tullamarine Freeway as it snakes around Essendon Airport; for obvious safety reasons, we don't want to confuse pilots when landing at night. Further along the same road, The Age's printing plant near Melbourne Airport has excellent full cut-off boxed lighting in its car park. Many tennis courts, railway stations and shopping centre car parks have also adopted this type of smart lighting.

Mark Griffin made this short sharp video for the 'Hidden Costs' Video Series which gives a nice little intro to the tyranny of lighting at night:

Fixing light pollution is a win-win-win. Good lighting prevents light going sideways and up, where it only does harm, and keeps it down where it is needed. Not only does well designed lighting reduce light pollution, it also:

  • Looks nicer, creating more attractive and pleasing night time environments.
  • Is more effective, enhancing visibility at night by reducing glare from light fixtures.
  • Saves money and uses uses less energy.
  • Improves human health and reduces impacts on animals.

All it takes is a bit of care and thought into designing appropriate lighting, which could easily be made a requirement through 'Outdoor Night Lighting Code' adopted by local government.

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