South West: Light pollution

Chris Rogers BBC South West Political Editor

When was the last time you looked at the night sky? Could you see the stars? The Politics Show South West investigates.

City of Bath, night sky in 1950

Can you view the heavens, looking deeply into an inky darkness punctuated by a myriad of sparkly points of light stretching from horizon to horizon.

If you live in a city you have no chance.

The light pollution generated by street lights, floodlights, advertising lights and even house security lights means that even the brightest stars and planets disappear into an orange glow that is the despair of amateur astronomers.

Professional astronomers, of course, moved out of our cities years ago!

City of Bath, night sky in 2003

Satellite maps of England show that severe light pollution increased by 17% between 1993 and 2000. In the rural areas where dark skies are still a possibility, there was a 27% increase in noticeable light pollution.

Dr Percy Seymour, Curator of the Plymouth University Planetarium says the problem is a mixture of light and dust.

Cities generate dust and other particles

Dr Percy Seymour

"Cities generate dust and other particles, not least from the introduction of things like motorised cutting wheels for making trenches in roads and pavements.

The dust hangs in the atmosphere and reflects back the increasing amount of light, forming the familiar orange glow. Astronomers call it the "capital effect".

Investigation necessary

A good time, then, for the Commons Select Committee on Science and Technology to start its own investigation into this often-overlooked degradation of our environment.

Committee member and Somerset MP David Heath is particularly keen.

He has seen the light glow grow even in his rural area and has been instrumental in getting the street lights changed on a rural roundabout in his constituency.

Beckington roundabout with original lights

The CPRE, the Council for the Protection of Rural England, has also launched a campaign it calls 'Light Blight', trying to raise awareness of the careless use of light by supermarket car parks and sports fields.

They are working in conjunction with the British Astronomical Association's Campaign for Dark Skies.

Street lights are regarded as a security measure, but CPRE/BAA says they don't need to be switched off, just better directed or upgraded so the light is not thrown up into the sky.

Beckington roundabout with new sky-friendly lights

Guidelines have been published but are not mandatory. Devon County Council has taken the idea on board and won an award from BAA for its efforts in replacing leaky lights on the Townstal Estate in Dartmouth.

But campaigners say that despite outbreaks of good practice, legislation is probably necessary.

Light is a pollutant?

Certainly government must play a much bigger role by at least classifying light as a pollutant, which at present it's not, and assigning a Department to address the issue.

The South West remains one of the best areas in the UK for dark skies, mainly because of the night wilderness of Dartmoor and Exmoor.

Skybeams used for a night time display, the ultimate pollutant

But even here there is a remorseless slow increase in low light pollution. Any measure to keep it down will be welcome.

Then we will have the chance to rediscover Joyce's ' heaventree of stars', the better to ponder the age-old mysteries of creation and our part in it.

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