Into dark — fighting light pollution
One of New Zealand’s most respected astronomers is petitioning the Government to introduce legislation to cut light pollution and preserve our globally-important “dark skies”.
University of Canterbury Emeritus Professor John Hearnshaw wants New Zealand to adopt similar laws as those recently passed in France, where businesses are now required to shut off illuminated signs and displays between 1am and 6am.
His petition, backed by the country’s official astronomy body, comes amid growing efforts to create new dark sky reserves across Aotearoa: most recently in South Wairarapa and Carterton.
Hearnshaw explained that artificial light at night — or ALAN — was an increasingly worrying problem, posing large and widespread impacts on a multitude of species that depend on natural dark.
In our largest city, researchers have found Auckland’s bright lights are likely hurting local ecosystems, while partly masking the lunar cycle and ruining residents’ view of the Milky Way.
Last October, a University of Auckland study reported how light pollution had caused hundreds of seabirds to crash into city buildings — including a dozen that crashed into the Sky Tower.
Globally, the problem has been shown to change the timing of dawn song in birds, stymie the nocturnal movement of small mammals and fatally attract phototaxic insect species to light.
Hearnshaw said ALAN had also been shown to have health impacts for people, such as disrupting our circadian rhythm and increasing risk of sleep disorders, obesity and depression.
Further, he said cutting light pollution — particularly from poorlyinstalled outdoor lighting that burned through electricity and projected light upward — could save money and energy.
“More than a third of light at present is actually being wasted, and that’s costing New Zealand millions of dollars each year,” Hearnshaw said.
“This isn’t about having complete darkness or anything like that — we still need light at night for safety — but just being very careful about where it’s shining.”
Hearnshaw proposed a national law that would set new controls on outdoor lighting, such as 10pm curfews for illuminated advertising signs, limits on what street lights could emit, and reductions in blue light across cities and towns.
Searchlights and lasers should be banned or strictly controlled, he said, while floodlighting of buildings should be curtailed and also subject
to curfew.
For commercial office buildings and shop windows, lights could be switched off after 10pm — or windows should be shielded with opaque blinds or curtains, which he also recommended to cut light pollution from homes. Hearnshaw said he and others had been lobbying councils through the Dark Sky Network NZ, but with limited success.
“We’ve been giving the same advice over and over to lots of councils — so I think there’s a need to be more efficient and have one national law, rather than lots of ordinances at council level.”
Royal Astronomical Society of New Zealand (RSANZ) president Nalayini Brito supported the appeal
for a new law, which she said would offer more protection for some twodozen aspiring and existing dark sky places in the country.
“I think that to preserve our dark skies for future generations, you have to control lighting — and it has to be legally enforceable.”
Brito also serves as a director of the International Dark Sky Association, which this month certified the Wairarapa Dark Sky Reserve amid just 20 other places worldwide.
Among astronomers, she said New Zealand remained one of the most important star-gazing locations on the planet. That wasn’t just because of our view to unique celestial features, but the relative abundance of dark skies over the country. Just over half of
New Zealand’s land area enjoyed pristine night skies, and the Milky Way was visible from over 96 per cent of the land area.
Currently, about three-quarters of the North Island and 93 per cent of the South Island still experienced only low levels of light pollution.
The RASNZ was now running a nationwide campaign to create an upto-date baseline for New Zealand and is recruiting Kiwis to observe levels next month, with a Facebook live event for February 17.
As well as promoting his petition, he was preparing a submission to the Natural and Built Environment Bill. Environment Minister David Parker has been approached for comment.