Light pollution is caused by poorly designed or unnecessary light shining wastefully where it is not needed...
Light Pollution
The human eye can pick out light from a distance of about two miles on a flat landscape, so light can have far reaching visual effects beyond that intended. Increasingly, many young people growing up in towns and cities might never experience this beautiful sight if we do not increase awareness and take measures to protect what we do have.
As well as affecting our ability to see dark skies, light pollution can have many negative impacts:
- Health and Wellbeing - lights that shine directly into windows and the general brightening of the sky can disrupt our circadian rhythms (body clocks) which can cause loss of attention, increased stress and fatigue.
- Safety - Glare and insensitive lighting spilling onto the road can distract or blind motorists with potentially serious consequences.
- Crime - It is not a given that installing a security light will deter crime. Bright lights can create contrasting dark spots that people can hide within, unseen from the outside.
- Wildlife - artificial light can be bad for wildlife in many ways - growth, development, reproduction, eating and locomotion all depend on the balance between day and night.
- Energy and Carbon Emissions - if the power of lights specified is more than needed, or , lighting is directed wrongly, or lights are on when they are not needed, a lot of energy can be wasted adding to the impact of climate change.
- Cost - It costs lots of money to power the grid system for lighting public places, homes, and commercial places. Wasted power though badly designed, installed or used lighting is an unnecessary cost.
Good Lighting - what you can do
Everyone can help reduce light pollution, reduce energy use and save money by improving the type of outdoor lighting they use.
Use lights only when and where needed
- Use the least number of fixtures that will meet the need.
- A time switch or motion sensor will reduce the time lights are on and save money.
- Use light for security only when it is monitored otherwise you are providing light for would be burglars.
Use only as much light as needed
- Use only the amount of light needed for the task.
- Choose light fittings and bulbs carefully and look for the Lumen output of the bulb – this is the amount of ‘visible’ light emitted from the bulb – less than 600 lumens is best.
Consider the colour temperature of lights
- Choose ‘warm lights’ rather than ‘cool or blue lights’.
- Temperature is measured by the Kelvin Scale (K).
- Look for bulbs which emit light at the lower end – under 3,000k.
Shine lights down, not up
- Direct lighting downwards to illuminate its target, minimising the spread of light near to, or above the horizontal.
- Down lighters should be mounted high, with the luminaire aiming downwards.
- Avoid up lighting whenever possible. If there is no alternative, keep the main beam angle below 70 degrees from the horizontal; use shields or baffles to reduce the spill of light outside the area it is needed.
where it is not needed - credit Bob Mizon
Nominate where you live as a Dark Sky Discovery Site
Dark Sky Discovery Sites are a nationwide network of places that provide great views and which are accessible to everyone. You can discover them on the Dark Sky Discovery website. They have all been nominated by local groups and organisations.
Do you have a local favourite top local spot to see the stars? If so, why not nominate it as a Dark Sky Discovery Site; encouraging others to enjoy and help keep it dark. Find out how on the Dark Sky Discovery website.
More Resources
You can find out more about Light Pollution and Lighting Solutions, on the following websites:
The Commission for Dark Skies – provides information and advice on light pollution and how to minimise it.
The International Dark-Sky Association - works to protect the night skies for present and future generations. Website has lots of information and resources.
Institute of Lighting Professionals – Aimed mainly at lighting professionals, but has a lot of useful articles, free and charged resources relating to lighting its impact and minimising pollution.
(CPRE) Night Blight - CPRE’s (Campaign to Protect Rural England) interactive maps of England’s light pollution and dark skies