17 January 2012 Last updated at 20:53 ET

Light pollution: Is there a solution?

 

By Denise Winterman BBC News Magazine

Few people in the UK now have a clear view of the night sky because of light pollution. The fight is on to reclaim the stars, but what are the possible solutions?

Look at the sky at night and what do you see? Not much most probably. Even in the countryside the stars are becoming harder to spot, with the sky glow caused by light pollution now visible for up to 50 miles (80km).

Only one 10th of the country now enjoys a truly dark sky, says the Campaign to Protect Rural England (CPRE), which carries out an annual star count. In the 1950s most of us would have been able to see the Milky Way.

Because light at night has brought indisputable benefits, its use has expanded to the point where it is "inescapable", said a Royal Commission on Environmental Pollution (RCEP) into artificial light and the environment.

"We are losing arguably the most culturally universal and historically pristine of all natural vistas," it warned.

Find out more

• Stargazing Live is on BBC Two, 16-18 January at 20:00 GMT
• The Great Big Dulverton Switch-off is on 18 January at 20:00 GMT

• More from Stargazing Live
• Find out about Great Big Dulverton Switch-off

To highlight the impact of light pollution on stargazing the entire population of Dulverton in Somerset is being asked to switch off their lights on Wednesday evening to show the contrast, as part of BBC Two's Stargazing Live.

Lighting at night is a complicated, often emotive issue as it provides valuable benefits as well as creating problems. But campaigners say they do not want all artificial lighting turned off at night, just the huge amount that is needlessly shone into the night sky every year. Sentiments shared by the Royal Commission.

As well as blighting the view of the night sky, inefficient lighting wastes over £1bn a year in the UK alone, according to the Astronomical Association's Campaign for Dark Skies (CfDS).

It has been blamed for disrupting the migration of birds, the breeding patterns of nocturnal animals and insect populations. Research has also shown it disrupts people's sleep patterns, while one study has suggested a link to breast cancer.

So with increasing calls for artificial light to be used only "when and where it is needed", what are the possible solutions to help ease the problem?

Intelligent lighting systems

You're in bed, but you can't sleep because the street light outside is too bright. So you send a text and minutes later it's turned off. Problem solved. Controlling street lighting, right down to individual lamps, could soon be possible thanks to intelligent lighting systems.

They use wireless technology to control lights from a central management system. It means at any time lamps could be adjusted in response to weather, circumstance and individual need. Sensors, texting and email could be utilised to convey the information.

Dark blue areas have least light pollution

"The potential is enormous," says Jacob van der Pol, product marketing and business development manager for smart lighting, NXP Semiconductors (Netherlands). "If there is a football match, the lights in the area can be told to come on when everyone is leaving and dimmed after they have gone. The technology allows you to adapt to circumstance."

Until now such systems have only been produced on a small scale, for individual houses and businesses, and have been expensive. This has made them unsuitable for street lighting because of the large number of individual lamps used, an estimated nine million in the UK. But the technology involved is now cheaper and it can also be installed in existing lamps so lighting stock does not necessarily have to be replaced, just updated.

Such a scheme has already been installed in the German village of Dorentrup and NXP Semiconductors is working with one of Holland's main energy suppliers on a project.

"The way street light is managed now is so outdated," says Van der Pol. "This technology has been born out of customer demand. People want more control."

He also points out there is the potential for it to be a new revenue stream for councils, as they could charge a small amount for each text. Something that might get the attention of cash-strapped local authorities.

There are issues with such schemes. Certain usage might increase disturbance, said the Royal Commission. The sudden activation of lights against a dark background might be more intrusive than a continuous light for those who have problems sleeping, or more disruptive to foraging nocturnal mammals or birds.

Ban 'Rottweiler' lights

They have been branded "Rottweiler lights" by critics - the 500-watt halogen lights attached to homes up and down the country, illuminating gardens and drives.

Being in a town doesn't stop me

Kylee Williams Amateur astronomer

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I've always loved astronomy, but it seemed out of my reach. I thought you needed expensive equipment and a certain amount of knowledge to even get started, but you don't. After last year's Stargazing Live I joined the Astronomical Society, saved up for a telescope and now I'm hooked.

I live in central Dartford in Kent and the area is heavily light polluted. I haven't let that stop me. I've built an 8ft (2.4m), fold-away screen out of wood and weed membrane. It's very lightweight and I use it to block street lights when I am out with my telescope.

City astronomy is a challenge, but it is really is amazing what you can see. I keep a book and note down everything I see. They've included things like the Andromeda Galaxy and the Globular Cluster in Pegasus. I even recently photographed Jupiter.

I could stay in the garden all night looking up. My husband must feel like he's lost me to the night sky.

• Try Stargazing's Planetary Activity Cards
• Or the Moon and Star Guide

Everyone from local councils to lighting engineers and government committees have recommended less powerful lights, but they are still being bought - often for as little as £4.48 - and fitted every day. They are too bright, too sensitive and often badly angled, sending unwanted light into neighbouring windows and the night sky, say critics.

Northumberland's Longstone Lighthouse, Britain's most powerful lighthouse, uses a 1,000-watt light source, yet people use 500-watt lamps to light a garden, says Bob Mizon, UK co-ordinator of the CfDS.

"Even if they are triggered by movement, it means next door's cat can set them off repeatedly. It's the equivalent of strapping on a microwave to the side of your house and putting it on for a few minutes about 50 times a day. They use so much energy and it's unnecessary. We're not saying get rid of the light, just use one that is appropriate."

Nigel Parry, from the Institution of Lighting Engineers, which publishes guidelines for good lighting, says the best security lights are not the brightest. "A 100-watt light can do the job well."

Critics argue that rather than boosting security, they actually dazzle so it is difficult to see, and create dark shadows which are better for hiding in.

The CPRE has called for them to be withdrawn from the shelves of DIY superstores and other retailers, saying there is no need for such anti-social, environmentally-unfriendly products on the mass market. Government committees have also recommended an outright ban in the past.

But Parry says there is anecdotal evidence that sales are actually on the rise, as councils start to turn off street lighting to conserve energy and money.

Homebase says it works "very closely with suppliers and in-store colleagues to ensure that customers are informed about how to reduce light pollution and considerate lighting when they purchase outdoor lighting".

Change the law

As it stands the UK has no national law that is just dedicated to reducing light pollution.

"It's illegal to dump rubbish in the street or the sea, so why isn't it illegal to dump rubbish into the sky?" asks Mizon. "It's just about the only part of our environment that isn't already protected."

Others countries have taken the unusual step of adopting such a law. The Czech Republic was the first in the world to do so in 2002. People can be fined if they do not comply. Slovenia has now followed. Dark-sky legislation is also on the books in several Italian regions and some US states.

Where artificial light goes

• 1. Upwards reflected light - unwanted but unavoidable light bouncing off the ground
• 2. Useful light - the right amount of light
• 3. Direct upwards light - wasted light shining above a fitting
• 4. Spill light - falls outside where it is needed
• 5. Intrusive light - overly bright and poorly directed, often going in windows

Source: RCEP and Environmental Protection UK

The UK has light pollution legislation but campaigners want the government to go further.

"What we have in this country is a series of bits of legislation so we can deal with some aspects of light pollution," says Martin Morgan-Taylor, principal lecturer in Law at Leicester's De Montfort University.

The Clean Neighbourhoods and Environment Act 2005 did criminalise light pollution. It made it a statutory nuisance in England and Wales and subject to the same criminal law as noise and smells.

In Scotland it comes under the Public Health etc (Scotland Act 2008) and in Northern Ireland the Clean Neighbourhoods and Environment Act (Northern Ireland) 2011.

"The problem with the current situation is that it's dependent on the attitude of local authorities," says Emma Marrington. "Some take light pollution seriously and will follow up complaints, other will just tell you to buy thicker curtains."

The Defra spokesperson said: "We are undertaking work to reduce the negative impacts of artificial light in a number of areas. This includes providing guidance on limiting light pollution to be included in local authority planning documents. We are also commissioning a research report to look at the effects of artificial light on biodiversity".

A big switch-off

"Lights Out" programmes have been successfully adopted around the world. Over 17 US cities participate, including New York and Chicago, and several in Canada. In the UK there is no such initiative.

The programme involves businesses turning off or dimming all decorative lighting at night during bird migration season. Artificial light confuses them and millions die every year by flying into windows. Nearly all tall buildings in Chicago co-operate for almost five months of the year, say organisers. Both birds and large amounts of energy are saved.

Tips to stargaze from a town

• Look for space, like a park
• Look for a clear horizon so you can see as much of the sky as possible
• Use a red torch to read charts and move around as it doesn't affect your ability to see in the dark so much
• You can put a sweet wrapper over a normal torch, paint it with nail varnish or use your bike light

Source: Dan Hillier, Royal Observatory Edinburgh

• Learn more about your universe
• Dark sky discovery stargazing tips

A "Lights Out London" campaign was organised in 2007, but it was for only one hour on one day. Campaigners say it's a missed opportunity.

"So many lights are left on in offices at night," says Mizon. "It can't be the case that every one is being cleaned at exactly the same time, throughout the night. It's staggering when you think of the light pollution and wasted energy."

Other countries also have annual "switch-off" events. Belgium has a "Night of Darkness" every year in certain areas, where street and public lighting are switched off for one night to promote the issue of light pollution.

The World Wildlife Fund promotes its annual "Earth Hour" in the UK and lights are switched off, but says the event is about the wider issue of global warming rather than light pollution.

Friends of the Earth do not specifically campaign on light pollution here, although it says it does come into its work. Neither does the Royal Society for the Protection of Birds (RSPB). The only event that is both annual and national is the CPRE's star count, say campaigners. This year it runs for a week from 20 January.