Light Pollution

At the beginning of the 21^st century, humanity is losing a valuable and beautiful part of its heritage. For the first time in history, poorly designed and badly aimed lighting is denying vast numbers of humanity a view of the night sky. Urban sky glow now pollutes nearly all of Britain's night skies. As amateur astronomers we have a responsibility to guard our night time environment against light pollution.

What is light pollution?  Light pollution is the popular name for sky glow - a brightening of the night sky caused by the scattering of artificial light by aerosol particles (e.g. water droplets) and dust in the air.

What causes light pollution?  Artificial light gets up into the sky in two ways. By far the greater proportion of upward light arises because the design or installation of many light fittings allows a significant fraction of the light produced to be emitted above the horizontal, so it goes up into the sky - this is the direct upward light. A much smaller proportion is upward light is reflected upwards from roads, pavements and buildings - this is the indirect upward light.

The following image of the Earth at night compiled by NASA from various spacecraft missions shows the extent of light pollution across the whole world: few areas of our planet are visibly dark at night!

Key detrimental effects of light pollution are:

• Damage to the global environment though waste of energy.

• Loss of an area of outstanding natural beauty - the nocturnal environment - through urbanisation of rural areas at night.

• Negative effects on wildlife: scientists now recognise some of the damaging effects of light pollution on flora and fauna.

• Negative effects on human health and safety. Recent medical research has shown that artificial night-time light has detrimental psychological effects and can stimulate an adverse physiological effect which reduces the body's resistance to disease.

• Badly directed, over-bright lights have been the cause of many driving accidents. For exampled, in the early 2000s, a court of law in the UK ruled that a security light was the cause of a fatal accident.

Many things can be done to reduce the problems of light pollution:

• use flat glass and ultra-low profile light fittings for exterior use and in particular for all street lighting,

• switch off lights if there are times during hours of darkness that they are not needed,

• prevent 'overlighting', i.e. use only the correct amount of lighting for the task in hand,

• in particularly sensitive (rural) areas ensure that lighting is used only when there is no better alternative,

• make external lighting subject to planning control,

• encourage industry to use efficient lighting and to minimise the amount of energy waste associated with light pollution,

• make light pollution a statutory nuisance and make lighting a planning issue.

Promote the facts! Some commonly heard extreme opinions on lighting and how to counteract them:

You can't have to much light

Overlighting and poor lighting result in glare, energy waste, environmental damage, and the waste of taxpayers' money.

But astronomers are in the minority

Everybody should have the right to see the stars - they are an important part of our environment and culture. Our schools now teach astronomy as part of the National Curriculum and as a separate GCSE subject. Young people should be able to undertake project work and appreciate the wonder of the universe at first hand. The BAA Campaign for Dark Skies (CfDS) is NOT just for the benefit of astronomers.

We can't get rid of all the street lights

Of course not! Astronomers have the same lighting needs as everyone else. We all need good quality, well-directed street and amenity lighting which serves the needs of the community, is efficient and preserves the darkness of the night sky for our descendents. Astronomers are against bad lighting which spills light into the night sky, not good lighting which directs it where it is needed, towards the ground!

More light equals less crime

There is little hard evidence to support this. Crime rates have soared as street lighting and security lamps have proliferated. Interviews with 300 burglars (ref. Home Office Crime Prevention Unit Papers 28 and 29) indicate that lack of occupants and risk-taking are the greatest stimuli to commit a crime, while the absence or presence of light is unimportant. Bright, poorly positioned, misdirected lights may well assist wrongdoers by creating deeply shadowed areas and glare which dazzles passers by. However, fear of crime may be reduced by exterior lighting. Good security lights are well-aimed, shine only downwards and are passive, infra-red sensor-triggered fixtures which retain an element of surprise to deter would-be intruders. A light triggered by an infrared sensor when an intruder passes nearby will use little energy and is likely to provide a far more effectively targeted response than a light left burning all night. Infrared CCTV is another technique that can be useful in remote locations. The UK Government's Home Security and Crime Reduction website agrees with CfDS that:

• Harsh, glaring floodlights are not a deterrent to criminals;

• Most break-ins take place in broad daylight (peaking in early afternoon), suggesting that most burglars are not unduly worried about committing crimes in lit areas.

I've never really looked at the stars. You can't see much from the town. What you've never seen you do not miss, so why bother?

Everybody has the right to experience the night sky. The universe is in a very real sense part of our natural heritage, involving the origin and destiny of the Earth and everything on it.

The best arguments in favour of reducing light pollution are:

• The massive waste of energy and fossil fuels caused by poorly designed street and external amenity lighting which, in many cases, sends 30% of the light into the sky - more than 50 per cent in the case of some globe lights. Light reflected from the ground and buildings contributes little to sky glow compared with that coming directly from the light fittings themselves. Re-directing all the light downwards where it is wanted will save energy and money and help the environment.

• Glare and over-lighting: many light fittings create much sideways glare, which can be a particular problem for drivers. A good light should be well-directed and almost invisible from a distance. Flat glass, full cut-off fittings, if correctly installed, emit no light above the horizontal.

• The wastefulness of all-night shop, advertising and display lighting, building illumination, upward floodlighting and permanent domestic and industrial security lights, both in terms of the energy they consume and the vast amounts of greenhouse gases produced. There is little point in leaving most shop advertising and display lights and floodlights on after 11 pm.

• The damaging effects of light pollution on wildlife are becoming recognised and some wildlife groups have already campaigned successfully for the removal of sources of light pollution. As well as the effect on animals and plants, recent medical research has discovered health hazards to humans from light pollution.

• The right of the individual to pursue the study of the night sky and to be able to appreciate the natural environment.

Although the problem of light pollution has grown in many areas so too has awareness and concern among astronomers and non-astronomers. Government departments, local, town and county councils, lighting designers, manufacturers, engineers and architects are at last beginning to see the importance of, and need for, quality lighting. Much of the concern about light pollution and much of the work to reduce it is due to people who are not astronomers: conservationists, naturalists, environmentalists, individual residents and local communities in areas blighted by light pollution. Many people acting individually, some with the help of organisations promoting astronomy, wildlife or conservation have successfully tackled local sources of light pollution. For example, a householder (a non-astronomer) in the UK took legal action against a commercial property whose security lights were causing a nuisance - the householder won the case. Recently a resident's association was formed in Birmingham, UK to fight a light pollution problem there. Conservationists are concerned about light pollution and in several cases have already teamed successfully with astronomers to campaign against light pollution. The Council for the Protection of Rural England (CPRE) has worked with the CfDS in lobbying for the reduction of light pollution. The CPRE, in common with many people living in the countryside, is particularly concerned about the loss of rural tranquillity due to encroaching light pollution. The International Dark Skies (IDS) organisation - based in the US - works on a global basis for the reduction of light pollution. A number of people in the legal field have recognised the need to include light pollution as a statutory nuisance.

Of course, there are vested interests trying to deny or undermine opposition to light pollution. Concern is growing, however. The professional community involved in the provision of lighting has recognised the problem and the Institute of Lighting Engineers (ILE) has been instrumental in defining solutions and producing guidelines to reduce the amount of light pollution. A particular concern is that although badly directed light can be recognised in law as causing a nuisance it is not yet officially listed as a statutory nuisance. With the global environment high on the agenda it is important to recognise the contribution to acid rain and global warming due to the energy wastage associated with light pollution. It has been estimated that the wasted light alone (not the total usable light) is equivalent to two generating stations. It is to be hoped that in the 21^st Century technology and environmental education will dramatically reduce the levels of light pollution from 20^th Century levels. How soon that happens depends on how quickly people respond to the problem.

Although the legal route represents one way to tackle the problem, often the best approach to reduce light pollution is by lobbying and persuasion. Wildlife groups, residents' associations, rural conservationists and astronomers have all achieved success by lobbying against light pollution problems. Write to your district council, county council, MP or the Department of the Environment, Transport and the Regions. Point out the problems associated with light pollution and detail some of the approaches to improve matters. Add your support for measures to combat light pollution when public consultation is invited. Express your views on light pollution to your county council in relation to its structure plan.  It is up to individual astronomers to add their voice to members of the public and groups asking for better controls on light pollution.

Since the early 2000s, thanks in part to the efforts of campaigners, light pollution has reduced substantially in some parts of the UK including parts of Suffolk and Essex. In many areas, however, light pollution has remained or got worse. Felixstowe and the surrounding area and Central Ipswich and Ipswich Docks and the surrounding area for several miles around have suffered severe light pollution for many years.

Clauses to reduce light pollution have been incorporated into councils' local plans and the UK Government's rural white paper (2001) has a paragraph emphasising the importance of controlling light pollution. The main political parties have made positive comments about the control of light pollution but it is up to individuals to keep the pressure up.

In 2003, the The House of Commons' Science and Technology Committee published its long-awaited report on light pollution and astronomy. Thanks largely to the admirable efforts of Peter Richards, OASI was one of 126 groups and individuals to submit written evidence to the Committee. Key conclusions and recommendations of the Committee are:

• There is convincing evidence of the value of amateurs to professional astronomers.

• Amateur and professional astronomers play a vital role in encouraging young people into science.

• School pupils should be able to study the night sky primarily with the naked eye.

• The Committee regrets that PPARC (Particle Physics and Astronomy research Council) and the Government have adopted a defeatist attitude towards both light pollution and UK astronomy.

• The adverse effects of light pollution on energy consumption are undisputed and the Government fails to take serious action.

• The Government should not dismiss the compelling evidence of light spread and pollution provided by satellite images of the UK at night.

• The Government must ensure that every local authority investing in new street lighting should be well informed of the new modern luminaires available. Local authorities that have not invested in new lighting must be strongly advised to install high pressure sodium lighting, the design of which should be shallow bowl or full cut off.

• The Committee considers 500W security lights to be energy inefficient and liable to cause nuisance and recommends that appropriate legislation should be considered to ban them at domestic sites.

• The Committee urges public bodies not to floodlight sports fields etc after 11pm.

• The Government should create a new Planning Policy Guidance (PPG) as soon as possible and ensure that all local authorities are made aware of their consequent obligations.

• The Government should afford special protection to observatories and local authorities should be obliged to consult on planning applications in the vicinity of such establishments. Observatories should be able to register with their local authority for protection.

• Quote from the Committee: Light trespass and glare affects astronomers, but it can also affect as all. We are persuaded by the evidence that light trespass is measurable and controllable. We recommend that obtrusive light should be made a statutory nuisance.

Of course, it remains to be seen if the Committee's fine words are translated into statutory instruments. Unfortunately, anyone watching Prime Minister's Questions on 22 October 2003, following publication of the Committee's report, could not be encouraged by the flippant way in which a question on light pollution was posed to the Prime Minister and the equally flippant answer. For details see the relevant sections of Hansard, reproduced below:

http://www.parliament.the-stationery-office.co.uk/pa/cm200203/cmhansrd/cm031022/debtext/31022-03.htm#31022- 03_spnew25

Mr Tom Harris (Glasgow, Cathcart): When was the last time that the Prime Minister had a clear view of the Milky Way galaxy? He will know from his close reading of the most recent report from the Science and Technology Committee that the growth of light pollution means that our own galaxy is now viewable from only 30% of the United Kingdom. Does he share my concern that such inter-stellar vandalism means that generations of children are growing up without ever having an opportunity to see for themselves the beauty of the night sky? Will he now instruct his Ministers to present a positive and constructive response to the report?

The Prime Minister: I am a little bit outside my area of expertise on that point, but fortunately I have a full brief. It says: Possible question: light pollution. Welcome the Science and Technology Select Committee report. The Government will respond soon. That's what we'll do.

Clearly, much work remains to be done.... Some steps that you can take are listed below. With so many groups beginning to realise the benefits of good lighting (ILE, BSI, CPRE, Countryside Commission, Highways Agency, major supermarket chains, Commission Internationale de l'Eclairage, CfDS, IDS,...) we can hope that eventually we will reclaim the night sky through sound argument and force in numbers.

• For further information on light pollution and how to combat it, contact the BAA Campaign for Dark Skies via http://www.britastro.org/dark-skies/

• The CfDS has a handbook which is full of information about the detrimental effects of light pollution, and what you can do about them. For further informaiton about the handbook and to order a copy, click here: http://www.britastro.org/dark-skies/handbook.html

• If you live in Suffolk, write to your county council: Suffolk County Council, Endeavour House, 8 Russell Road, Ipswich, Suffolk, IP1 2BX.

• Write to your MP at: House of Commons, London, SW1A 0AA. Ask him/her to insist that the UK adhere to European measures on energy saving and heritage protection through firm and proper action on skyglow.

• Write to the DoE, 2 Marsham Street, London, SW1P 3EB asking why, in spite of their campaign Wasting Energy, Costing The Earth, and mention in the 1995 Rural England White Paper of the need to save energy and control light pollution, they still refuse to take action to tackle the total lack of regulation of exterior lighting.

• Explain to those who see modern, low-glare lighting as dim that such lighting is in fact more efficient, better directed and at least as effective at providing security and safe conditions as its more high-glare predecessors. Further, modern lighting, through increased efficiency, is cheaper to run.

• Research the approach of your local police and Neighbourhood Watch scheme to lighting. The arguments for appropriate security lighting are explained in the CfDS leaflet on security lights.

• Try to forestall poor lighting on new developments by studying planning applications and developing links with your local council.

• Assist CfDS by subscribing to the CfDS newsletter, donating to its fighting fund, becoming a local officer or distributing its literature.

• If dealing with local media insist on some editorial control so as to avoid headlines such as Star-gazers Call For Big Switch-Off. Make clear that light pollution affects many other interests than astronomy.

• Tell astronomers and non-astronomers about skyglow, stressing its waste of energy and money. Ask what they would think if, by analogy with the waste of resource represented by skyglow, their water main leaked every few metres.

• Convince interested parties that astronomers want appropriate lighting, not no lighting.

• Ask libraries, electronic bulletin boards, environmental offices, education departments, etc to carry CfDS literature.

• Offer to speak to schools. Astronomy is part of the national curriculum, and you can introduce light pollution into the discussion.

• Ask neighbours about their lighting plans, and show them at the telescope why you enjoy the night sky.

• Approach those with obtrusive lighting. Many individuals and organisations with obtrusive lighting will not even be aware that they are causing a problem! Those who have done so often report improvements.

• Remember that carping criticism and "broadsides" don't win friends, but friendly and persistent persuasion just might!

Links:

• BAA Campaign for Dark Skies

• CfDS handbook

• Council for the Protection of Rural England (CPRE)

• International Dark-Sky Association

• Institution of Lighting Engineers

J Appleton Original: Newsletter November 1995; June, July 1997; November 2000; April, November, December 2001; November 2003; March 2004 Updated 04 August 2009