Stars in the city

It could be, but you wouldn't know it. Most of us never see the stars because of glare from city lights. But moves are afoot to bring back the night sky, says Oliver Bennett

Rome at night is something to behold. Its treasures, from the Colosseum to the Trevi Fountain, are artfully lit to illuminate every splendid curve and throw their ancient shadows into sharp relief. The Tiber seems to be ablaze with reflected light. Yet for those in search of romance, there is something missing: the night sky. Rome has 170,000 public streetlights, and the city's director of public works laments, as perhaps only a Roman bureaucrat might, "they are stopping us seeing the stars".

That's why the city is planning to turn them down. Street and hotel lights will be dimmed, with internal shop lights turned off at midnight. And monument illuminations, which already fade in the evening, will be darkened further.

When it comes to light pollution, Italy is not even among the worst offenders. England makes the second largest glare contribution in Europe and is only pipped by the Netherlands, whose emissions are bumped up by its large concentrations of agricultural greenhouses. Thankfully Italy is not the only country that is doing something about it. Here in Britain, early next year new light-pollution legislation comes into force as part of the Clean Neighbourhoods and Environments Act - passed in April 2005 - which makes running anti-social lighting a criminal offence.

"We're pleased, with reservations," says Martin Morgan Taylor of the law department of De Montfort University, a long-time campaigner and associate of the Campaign for Dark Skies (CfDS). "We've been trying to get light pollution regulated since the Eighties."

The anti-light-pollution lobby has been growing since the CfDS was set up in 1989 by members of the British Astronomical Association (BAA) to counter growing "sky glow". Bob Mizon, the CfDS spokesman and a former teacher, runs a travelling planetarium to show star-starved children the joys of the night sky. He is delighted that awareness has been raised. "Ten years ago, the average Briton wasn't aware of it. Now it's a big thing.

"It has reached a critical level," adds Tom Oliver of the Campaign for the Protection of Rural England (CPRE), which launched big campaigns in 1994 and 2003 to educate the public about light pollution and to promote the joys of the night sky. "There has been a great escalation in the number of lights and, complaints are rising steeply."

Birds' natural patterns of movement are disrupted because artificial light creates "false dawns". Sleep deprivation compromises their ability to hunt prey, and the blurring of the seasons can even confuse the natural navigation system that governs their ability to migrate each year. Trees and plants are put out of kilter by "false days", which upset photosynthesis patterns and stimulate leaf-drop at the wrong times of the year. Owls, mice and even fish have their natural rhythms affected. Then there are all those moth deaths.

There is also a highly intriguing human-health dimension. In the US, it has been suggested that breast and other cancers might have some connection to lighting due to the suppression of melatonin production - one of the most pressing health problems associated with the disruption of circadian rhythms. Nor should children sleep with the lights on, which has been suggested is a cause of myopia. But the CfDS doesn't want to dwell on the health aspects of the overlit environment, because so much remains speculative - although Mizon is annoyed that some councils require a doctor's letter before acting on the removal or repositioning of a light.

The need for a dark sky is wider and deeper than that: it is linked to our sense of place in the universe. "Look at what star-gazing has done for humans," says Mizon. "Our sense of wonder came from the stars, and astronomy is the oldest science. We cannot lose that."

In England, 85 per cent of people are unable to view the stars because of light pollution. The crux is that outdoor lighting has changed in both scale and quality in the past 30 years. In the early days, light-scatter and pollution was caused largely by poorly-aimed streetlights. This source remains, but has now been augmented with new sources of light pollution from household security lights and sports centres: indeed, Mizon claims to know of cases where golf driving ranges can be seen 40 miles away.

Shops can be culprits, too, due to their tendency to keep displays on all night for advertising purposes. Offices and schools are often profligate with lights: at one high school, Mizon counted more than 150 lights on in the middle of a bright day. Then there is the growing tendency for heritage and landmark buildings to be lit at night. "Lighting landmark buildings is becoming more common," says Mizon. "We don't have a problem if it's done well, but often the light scatters everywhere."

The campaigners are anxious not to be seen as killjoys. "We're not anti-lighting," says Mizon. "Obviously we need lights. We're simply saying that there has to be an appropriate use of them and that we should try not to waste light." As far as lighting buildings is concerned, the CPRE is trying to promote the use of "episodic" lighting such as Christmas lights. Morgan Taylor suggests a "curfew": "You could light your building or shop until 10pm, say, which alone would save a fortune" - and proposes intelligent spotlighting rather than floodlighting. "It's odd that so many churches are floodlit when the Church is trying to promote Operation Noah, which aims to save energy."

"People don't seem to realise that lighting is energy," says Mizon. "A 100-watt bulb, if left on for a year, creates quarter of a ton of carbon dioxide, the biggest greenhouse gas."

On a domestic level, there is a growing trend for external security lights. "Many of them are 500-watt, which is half as bright as the brightest lighthouse in the UK," says Mizon. Morgan Taylor thinks that they consitute a major source of light pollution and wasted energy. "My conservative estimate is that there are around 2.2 million such lights in the country. Perhaps they're on for only a quarter of an hour a night: but that's a massive amount of power."

And these "Rottweiler" lights, claims the light pollution lobby, are not even efficacious in preventing crime. "I call them 'insecurity' lights," says Morgan Taylor, who, when he wrote a paper on light pollution in 1997, canvassed insurance companies and found that none had factored in lights as a deterrent against burglary.

"They're so bright I'd argue that they help burglars - and anyway, remember that most burglaries happen during the day. These floodlights are more about the fear of crime than its prevention." Mizon has tried to stop them being marketed as "security" devices, but with limited success.

Councils and responsible landowners are also getting on-message with the light brigade by focusing their lamps downwards, rather than up into the night sky, in streets and institutions. And light-emitting diodes are set to replace old streetlights, which Mizon applauds. "They're a lot smaller: the size of a matchbox compared to the metre-long lights we used to use." About a hundred councils now have good lighting policies, he adds.

Indeed, it should soon be the case that planning officers consider light pollution - via an addition to Planning Policy Statement 23 from the office of the Deputy Prime Minister - when granting new permissions. ("We're still waiting for it," sighs Oliver.) Another boost to the dark-sky movement is that several councils have banned so-called sky-beam advertisements.

"The inky night is one of the most profound experiences a human can have," Tom Oliver says. "I'd argue that the natural experience of night-time is vital to human health and happiness."