Light Pollution and Astronomy by Dr Michael Elves

Science Policy and Evidence

Light Pollution and Astronomy

A Case Study

Astronomy in the UK

The Royal Astronomical Society (RAS) Promotes study of astronomy and solar-system science Mainly professional astronomers

The British Astronomical Association (BAA) Supports Amateur Astronomers Supports the Campaign for Dark Skies

The Society for Popular Astronomy (SPA) Encourages beginners to the science of astronomy and promotes astronomy among the general public. Promotes an interest in observing the sky among its members

Astronomy in the UK

200-300 tenured academic astronomers plus “several thousand” making a living from Astronomy (incl PhD students)

Over 3,500 amateur Astronomers

About 50 Universities were offering undergraduate modules in astronomy

About 25 Universities were offering Postgraduate courses in astronomy

About 33 Observatories attached to Universities

Why is Astronomy and access to dark skies important?

For the understanding the structure and nature of the Universe

For the Promotion of the study of geophysics and related branches of Science As a means of enthusing young people for the study of science – astronomy included in the National curriculum

As a means of introducing the wider public tothe wonders of the universe through the night skies

Light Pollution as a threat to Astronomy in the UK

83% of people said that the light was affecting their view of the night sky from their property. (CPRE and BAA survey)

Star trails over Winnats Pass, Derbyshire

80% of members cannot, or can only barely, see the Milky Way. (SPA) Over half of members have to travel between 5 and 50 miles to find acceptable viewing conditions. (SPA survey) “It’s a sad fact that many children will grow up never seeing the Milky Way, our own galaxy, because of the impact of artificial light.” (CPRE)

What is Light Pollution?

Light pollution is “Artificial light that is allowed to illuminate, or pollute, areas that are not intended to be

lit”

“Good illumination is the right amount of light, where it is needed, when it is needed”

( The BAA Commission for Dark Skies)

Light Nuisance aka Trespass


= Light spilling beyond the boundary of the property on which the light is situated – sometimes shining through windows and curtains - E.g. Security lights

Glare


= The uncomfortable brightness of light when viewed against a darker background – E.g. Street lighting, Sports fields

Sky Glow


= The pink or orange caused by artificial light from various sources shining upwards being scattered by airborne dust and water particles

1950

2000

View of the City of Bath

Light Pollution – the growing problem

Before and during the a massive power failure that affected 55 million people.

Light Pollution – the impact on Astronomy

The Orion Constellation

From a Dark Sky area From a Residential area



Stars to Mag 6 in natural dark sky

Stars to Mag 3 in typical suburban sky

House of Commons Science and Technology Select

Committee Inquiry 2003


127 Submissions of EvidenceIndividuals - 78Astronomical Societies and Observatories – 30Chartered Institutions – 5Government Departments and agencies (inc PPARC) -9Local Authorities 2Others -3

Astronomers, Campaigners, Lighting Specialists, Regulators, Government Ministers, PPARC

Two Witness Sessions – 16 Witnesses

The Evidence


Consequences of Light Pollution in the UK

Amateur astronomers find it difficult to use their telescope due to light trespass Universities finding it difficult to continue active programmes of astronomical observation in the UK.

Increasing dependence on telescopes and facilities overseas

Need to relocate major UK telescopes elsewhere – e.g the Isaac Newton

Royal Observatory,Greenwich

Herstmonceux Castle, Sussex

1957

La Palma, Canary Islands

1984

Operational Telescopes funded by PPARC

Telescopes Location Type

Anglo-Australian Australia Optical/nr Infrared

Carlsberg Meridian La Palma Optical

Isaac Newton La Palma Optical

Jacobus Kapetyn La Palma Optical James Clerk Maxwell Hawaii Submillimetre

Gemini Hawaii and Chile Optical/nr Infrared

Merlin England Radio

UK Schmidt Australia Optical

William Herschel La Palma Optical/nr Infrared

UK Infrared Hawaii Infrared

(As in 2003)

New Telescopes under construction in 2003-4

Atacama LargeMillimetre Array Chile

Liverpool Telescope La Palma

Visible and Infrared Telescope for Astronomy Chile(VISTA)

Measures to combat Light Pollution

Government’s Policy Planning Guidance notes (PPGs) PPG12 -Local Authorities to have regard to Light pollution

BUT - No explanation re how this is to be done – refer to PPG23

PPG23 – Planning Policies to include “possible impact…..of releases of light.”

BUT - No guidance on how this should be done.

Floodlighting Historic Buildings Floodlighting Sports Grounds Outdoor Advertising Control

Local Authorities’ Planning Policies

Other PPGs touching on specific lighting sources

BUT - No guidance on guidance on Street or security lighting


The LawEnvironmental Protection Act 1990“Section 79. Statutory nuisances and inspections therefor.”

(1) “States that harm health”(2) Smoke(3) Fumes or Gases(4) Dust, Steam, Smell, other Effluvia(5) Animals(6) Noise

These are all criminal offences

Lists matters which constitute “statutory nuisance” -

Does not include Light


The LawOnly remedy for Light nuisance lay in the Civil Law

Must sue owner of the offending light in the Civil Courts

Loser bears the legal costs of both sides

You will have to prove the nuisance - Difficult!

BUT a few have been successful: Stone Haven and District Angling Association v Stonehaven Tennis Club (1997) – sports ground lights

Bonwick vs Brighton and Hove Council (2000) – local authority lights

Bacon v Gwynedd CC Tywyn (2004) - sports ground lights

Cases rarely succeed

How can light Pollution be reduced?Street Lighting:

Low Pressure Sodium lights (SOX)- large luminaires and difficult to control - orange tinged glow High Pressure Sodium lights (SON)- more controlled- light can be directed downwards

A solution: Replace old SOX street lights with SON lamps in full cut off Luminaires – reduce light spread above the horizontal.

Security Lighting:

Over-powerful lamps Badly positioned and mounted

Solutions: Better positioning and use lower power lamps

The Problem

What did the Committee conclude?

Government has adopted a defeatist attitude towards light pollution.

The Government fails to consider light pollution with all its adverse effects seriously.

No doubt that light pollution is getting worse and the Government should take serious action to tackle the problem.

The Highways Agency is giving environmental considerations top priority in replacement of lights. Local authorities must be strongly advised to install High Pressure Sodium lighting, with appropriate luminaires when replacing lighting.

On Street Lighting:

Based on the Evidence:

The Government should issue clear guidance on the most suitable types of lighting.

Government and PPARC should support amateur and professional astronomers.


Planning guidance on light pollution to local authorities lacks coherence and force.

Government should provide new guidance tackling light shining above the horizontal by controlling direction, position, type and duration of lighting.

Planning Permission Conditions should be imposed for new buildings with floodlighting, new floodlighting systems or new car parks, to ensure it is not obtrusive and is energy efficient.

Lighting and Planning

For normal domestic purposes 500w security lights are energy-inefficient and liable to cause nuisance. Remedy is legislation banning the sale of 500w lights.

Lighting schemes must only include lights that do not shine above the horizontal.


If the Government accepts the Committee’s recommendations and starts the process of reducing light pollution then -

Light trespass is measurable and controlable.

Obtrusive light should be made a statutory nuisance.

“In 20 years time it might then be possible for young people studying astronomy to see the Milky Way in the UK night skies once more.”

What happened next?

an increase in light pollution as a result of a wide range external lighting.

the significant contribution to research made by amateur astronomers.

“The Government welcomes the Committee's focus on the planning system to deal with light pollution. It will have helped to raise awareness of light pollution with those responsible for making decisions.”

the valuable role that astronomers play in introducing young people into science.

The Government’s Response

the adverse effect of light pollution on amateur astronomy, the public's enjoyment of the night sky and the potential impact on education.

The Government recognises :-

What happened next?Planning and Light pollution

2004 - New Planning Policy Statement (PPS) 23 Provides guidance in Annex 3: “Planning and Light Pollution”

2012 - National Planning Policy Framework

Replaces PPS23. Consideration of the impact of light pollution on local amenity, intrinsically dark landscapes and nature conservation.

2009 - Royal Commission on Environmental Pollution (RCEP)

Highlighted impacts of artificial light on human health and on wildlife.

2011 - Natural Environment White Paper (NEWP)

Vision for next 50 years to protect natural environment and “intention to work with industry and other bodies to reduce the negative impacts of artificial light and protect dark areas.

Increased awareness of the problem.

- Clean Neighbourhoods and Environment Act (2005) Section 102.

(1) Section 79 of the Environmental Protection Act 1990 is amended to include artificial light emitted from premises so as to be prejudicial to health or a nuisance;

The new law makes 'exterior light emitted from premises - under some circumstances - a statutory nuisance and a criminal offence.

The first UK law tackling light pollution came into force in 2006 -

What happened next?

The Law

Local Authorities have duty to investigate complaints of Light Nuisance and take action.

One objective of Committee achieved!

What happened next?

Airports harbour premises railways premises tramway premises bus stations and any associated facilities public service or goods vehicle operating centres Lighthouses prisons

The Law

But there are some exemptions from the new law -

Premises regarded as of “strategic importance”

List reviewed in 2012 and decision was to retain them

WHY?

Campaign for Dark Skies - 500W 'security' lights feature in many of the complaints.

What happened next?Security Lights

Sale of 500W tungsten halogen 'security' lamps banned from September 2009.

THEN -EU Directive -

But for energy efficiency reasons not light pollution. Raised awareness of light pollution by Local Authorities.

... believed there is no case for banning the sale of security lights to the public.

Government recognised the nuisance caused by poor and incorrectly installed lights – BUT ...