Return to the Dark Side

New Zealand will set an environmental world precedent if it can persuade UNESCO to recognise a new type of World Heritage Site – a Dark Sky Park in the Mackenzie Basin from which people will be able to see the natural beauty and brilliance of a star-filled night sky unspoilt by light pollution.

“It really is a wonderful night sky here and there are very few places left in the world now where you can get that view,” says Professor Phil Butler, head of physics and astronomy at the University of Canterbury and a strong supporter of the proposal.

The relentless increase in urbanisation across the industrialised world has obscured the night sky with a blanket of light pollution, but Dark Sky Park supporters are fighting back. A high-profile campaign – saddled with the grandiose title of the “International Conference in Defence of the Quality of the Night Sky and Right to Observe the Stars” – just launched in La Palma in the Canary Islands, is championing the importance of unpolluted skies to humanity.

Satellite images of the dark side of our planet show the massive amount of energy that pours into space every night as light pollution. Given the worldwide concern over climate change, carbon emissions and energy conservation, the conference is well-timed if it can raise global awareness of the triple evil of inefficient lighting, wasted energy and light pollution.

Everyone is familiar with “urban sky glow”, the orange haze that hangs over urban environments at night. There’s also the “in-your-face” glare from excessively bright and/or badly positioned lights, while “light trespass” is caused when badly directed or unshielded light spills in unwanted directions – such as into the sky or through your bedroom window. Light pollution can be significantly reduced, however, by using full cut-off lights that direct light onto the target area and prevent it escaping upwards and sideways. Usually, this enables operators to use smaller wattage bulbs or fewer lights overall, reducing energy use.