Twinkle, twinkle, little star…

Not so long ago, around 7,000 stars were visible in the night sky above Madrid but barely 50 can now be seen, given the increase in artificial light in the capital over the past two decades.

Ricardo Martínez, the president of the Madrid Astronomy Group — whose headquarters are in Cuenca, 140 kilometers from the capital — says that his organization has been campaigning since 1998 to get City Hall to tackle the problem of light pollution. He wants them to start with globe-shaped street lamps, which project their light upwards. The municipal authorities say that more than 14,000 of these are in place in the city, a figure that Martínez says is a gross underestimation, adding that City Hall also refuses to take the problem of air contamination seriously.

The two problems are related, argues Federico de la Paz, of the Canaries Astrophysics Institute. "There is a connection between the two, because light pollution is made worse by the amount of particles in the air: the more air pollution, the more reflected light," he says. His organization has managed to convince the regional government of the Canaries to implement measures to reduce light pollution, particularly on its roads, but says "there is still a great deal to do in mainland Spain, where so much light is wasted."

Martínez describes what he calls a "giant mushroom rising 30 kilometers into the sky over Madrid, which can be seen from 300 kilometers away." On February 12, a photograph was taken of the Spanish capital from the International Space Station, 400 kilometers up in orbit. In it, Madrid glows in the dark — its airport, its ring roads, its main thoroughfares, and its squares are all visible.

"Nobody is saying that we should turn off street lamps in the capital, but it makes no sense to light up monuments or to have advertising hoardings illuminated all night," says Alejandro Sánchez, a researcher at the Department of Astrophysics.

Astrophysicist Fernando Jáuregui is the president of the Association Against Light Pollution, and has led several research projects into the problem. He says that while Madrid is the worst offender in Spain, this is a national problem: the country uses three times as much light per inhabitant as residents of France or Germany do.

He says that successive governments have failed to instill in people the importance of more efficient light use. "These days we wouldn't understand a country that was proud of the amount of chimneys it had belching out smoke, as happened during the industrial revolution, but we have a long way to go in terms of light pollution." He says it isn't just a question of the wastage of advertising hoardings lit up during the night — there are also street lamps that waste more than half of their ability to illuminate by lighting up the sky or apartments in front of them. He says that studies show that growing numbers of people are being affected by artificial light, which is limiting the quality of their sleep. "We have adopted an attitude of the more light the better," he says.

Some Spanish cities have passed laws to reduce light pollution. In Catalonia shops and hotels must turn off lights by a certain time, or face fines. The problem is that the authorities largely fail to sanction those who don't obey such ordinances. Andalusia has also introduced legislation, as have the Balearic Islands.

Madrid City Hall has passed laws obliging shops and other commercial premises to turn off their lights by midnight. The city turns the lights off at all public monuments at midnight, with the exception of the Cibeles Fountain and the Puerta de Alcalá, which remain lit up until 1am. The Royal Palace remains lit until dawn.

"The problem of light pollution dates back to the middle of the 1990s, when City Hall began increasing the number of street lights — even installing lighting on motorways and ring roads... Those were the years of wasting energy, and we are still paying for them," says Francisco Pujol, president of the Skies Protection Group, which works with other organizations to try to reduce light pollution in the capital. He says that the laws are there to promote better energy use and to protect the atmosphere — "The question now is applying them."

Pujol says that Madrid's legislation on lighting is not being followed, singling out the traditional green crosses to indicate pharmacies, or the many globe lamps still to be found throughout the city. The Madrid authorities say that they have recently implemented a project to renew lighting, and to replace old lamps with more energy-efficient bulbs. But Pujol argues that the economic crisis has made a far bigger contribution to limiting lighting.

At the international level, an initiative called Starlight is trying to get UNESCO to declare the night skies as part of the world's natural heritage. "Our children do not know what the Milky Way looks like. They have seen it in books, but they have never seen it for themselves. That is a tragedy," says Federico De la Paz from the Canary Islands, where the constellations can still be seen in all their splendor.