Light pollution: Is there a solution?

Road and lights

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

Forest and rotating constellations
  • 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

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.

Light pollution map 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

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.

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

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.


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  • Comment number 318.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • rate this

    Comment number 317.

    In a lifetime of driving Britain's motorways I have never been able to understand why a road which can only be used by vehicles which must have headlights has to be illuminated like a football stadium. These roads are primarily in country areas so produce massive light pollution for no real benefit to anyone.

  • rate this

    Comment number 316.

    167. Iain:
    “Not everyone has an urban garden or lives in a town with neighbouring properties and a 100W most certainly does not work in all locations".

    2 or 3 100w lights spaced across a big area & pointing down provides better, safer, cheaper lighting than a 500w halogen pointing _across_ it. That's a recipe for glare, dazzle and dark shadows - not good or safe for the user or passers-by.

  • rate this

    Comment number 315.

    As a Physicist doing my master's project on Stellar Spectroscopy, it can be a bit of a pain. A significant section of the sky is almost unviewable here because of light pollution. Even looking at other parts of the sky away from the City we get the double line of sodium appearing in our Spectra. It's not a hindrance really but it's hit me this year how awful the light pollution is in this country.

  • rate this

    Comment number 314.

    I grew up in the unlit countryside, and every time I go back I'm astonished at how much you can see in the night sky. It's truly overwhelming and a reminder of just how small we really are. I think we'd probably have a better, more philosophical outlook on life if we could just look up and clearly see the stars every now and then.

  • rate this

    Comment number 313.

    My garden light is 60W and on a 15 sec sensor (no movement, no light). For street light nuisance, try installing shutters in your bedroom window, rather than flimsy curtains. I live in the suburbs of Cambridge and I have see then Andromeda Galaxy with the naked eye.

  • rate this

    Comment number 312.

    I'm glad they are slowly getting rid of those yellow street lamps if anything they were worst at light pollution.

    But I would rather see where i'm walking than to look up at the stars. There's a time and place for stargazing

  • rate this

    Comment number 311.

    "The problem with the current situation is that it's dependent on the attitude of local authorities," - Councils are often the worst offenders, look at many schools and public buildings. Inefficient non-directed lighting.

  • rate this

    Comment number 310.

    There are a number of street lamps in my area that are useless because of the trees that have grown around the lamp and block ANY light getting to the road! That would be a good starting point, perhaps?

  • rate this

    Comment number 309.

    Being cynical, and somewhat realistic, why would councils encourage a reduction in lighting, when this will have a knock-on effect on road traffic accident figures.
    I'd like to live a life closer to nature, just like everyone else, buts sacrificing public safety for the sake of hobby astronomists seems a bit silly.

  • rate this

    Comment number 308.

    The last time I was stargazing it was with the aid of a street light, the bulb fell out and hit me on the head.

  • rate this

    Comment number 307.

    I want to live where I can be safe and secure in the knowledge that I can see/go outside outside my house at any time of the day or night. Safety must be the prime objective. I would like to see all roads lit as this will reduce the horrible glaring head lights from modern cars.

  • rate this

    Comment number 306.

    Lights are great for criminals. No messing about with torches or lanterns and attracting attention. Free lighting to see who is about and where to go. The only thing lighting does is make people feel better because the intuitively believe "lights = security" because of our human nature of fearing the dark. However, intuition isn't always correct.

  • rate this

    Comment number 305.

    Regarding the increase in crime during WW2

    Yes, there was an increase but not necessarily nor wholly due to the blackout

    There is always an increase in crime during periods of hardship, as there is now with the increase in shop-lifting and metal theft

    If there were to be light reduction and crime continued to rise, no doubt the correlation would be seen by many to be 100% causation

  • rate this

    Comment number 304.

    286 Phil T

    Much of the difference is that car headlamps are carefully designed, adjusted and regulated so that the light goes where it's supposed to go and illuminates what it's supposed to illuminate, whereas a cheapo exterior light is just a powerful lamp with a bit of tinfoil behind it, that vomits a huge pool of light in the approximate direction of wherever it's been clumsily aimed.

  • rate this

    Comment number 303.

    The Blackout in WW2 caused a massive increase in accidents. It prompted the King's Surgeon, Wilfed Trotter, to write in British Medical Journal that the Blackout was killing 600 British Citizens a month - which was more than the Luftwaffe.

    It would be nice if astronomers could see the stars more clearly but not at the expense of peoples safety.

  • rate this

    Comment number 302.

    240. gettingstarted

    The amount of extra light bouncing up off of the ground cannot exceed the light which was previously going up anyway. Otherwise you've just invented perpetual motion. And you haven't.

  • rate this

    Comment number 301.

    There are many advanced models of streetlighting (LED) and central management systems being used across the UK by numerous Local Authorities. Birmingham is installing one of the most advanced lighting systems in the World (this has been covered by the BBC) along with others such as Suffolk for example - these largely address the problem. The issue I guess is funding priorities.

  • rate this

    Comment number 300.

    Security lights should not be sold to the public, only to qualified electricians and subject to planning permission. This might deter the proliferation of inappropriate lights. The one across the road from me dazzles every room in my house every time a cat walks past it. Street lamps should be turned off after 11.30 pm in residential areas to promote better sleep and public health.

  • rate this

    Comment number 299.

    YES PLEASE!!!! When I look out of my window at night I see a whole skyline full of them. They actually blind me when I sit on the couch. I sometimes wake up and night and wonder if the sun's coming up. And they're multiplying. When I moved here there were two of them, now they're everywhere.

    Install more lights, but not as bright, and lower down, is my advice.


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