There’s been a steady stream of worries that artificial lights are steadily eroding our ability to see the stars. And a recent essay published in Science describes how artificial light affects the timing of events such as greening of plants in spring and autumn leaf-coloring. This is one of the many recent studies that demonstrate the direct or indirect impact of light pollution on plants and animals.

“People are getting aware that darkness is no [longer] darkness. This is one of the elements that is contributing especially to the decline in the species variety as well as the decline of biodiversity,” says Jacques Falcón, research emeritus at the French Scientific Research Centre (CNRS).

Now, thanks to a voluntary program in France, more communities are taking steps to limit light pollution.

Organizing for darkness

Despite this growing body of evidence, the use of artificial light has been constantly increasing over the past few years. A 2017 study shows that from 2012 to 2016, the amount of area lit by artificial light around the world grew by 2.2 percent per year.

While laws in France recognise light pollution, the level of awareness about this issue among the public is not the same as it is for air or water pollution. To overcome this problem in France, the organization ANPCEN (Association for the Protection of the Sky and Nocturnal Environment), of which Falcon is a member, was created to incentivize the fight against light pollution in France. Every two years, the association releases a list of French towns and villages that receive stars for their efforts in controlling artificial light.

“We started the label, from one to five stars, in 2009. This was 10 years after our association was founded. It is not only a great valuation exercise for the recipient communes but also an encouragement to progress for the neighboring towns and villages,” said Anne-Marie Ducroux, honorary president of ANPCEN.

An indication of the growing popularity of this initiative can be gauged from the increase in the number of communes that have voluntarily participated over the past 12 years. While the first list published in 2009 has just 39 communes, the one published this year has 364.

According to Ducroux, ANPCEN favours a global approach to combat light pollution. “We deal with different aspects related to biodiversity, energy, health, climate, astronomy, and public expenditure, all at the same time, to aim for consistency of choices. We raise awareness not only at the local level of municipalities but also at the national level, such as the Parliament. Also we are involved in advocacy which has notably resulted in light pollution getting included in four laws and several regulations,” Ducroux says.

Getting a star

Participating communes have to complete a questionnaire of about a dozen pages long related to energy consumption, biodiversity, citizen awareness and measures taken to avoid intrusive lights, among other things. Each item in the questionnaire carries a score, and the  sum determines the number of stars awarded.

One commune that gained three stars is Veyrac, located in southern France. According to Franck Selleret, who is the councilor in charge of sustainable development for the commune, the key aspect of the ‘star village’ initiative is that it motivates you to look into some aspects of administration such as energy consumption and to rectify any problems you find.

“Undoubtedly, getting these stars also lends credibility when it comes to requesting for funds for the development of the commune,” he says. Personally for Selleter, dark nights also mean an opportunity to pursue his interest in astrophotography.

Ducroux wishes to see a growing number of municipalities and private actors involved, because all light sources contribute to light pollution.

Falcón says that even though he lives in a small village, the quality of the night sky is poor due to its proximity to a big city. “Even if small towns shut down lights at night, the big towns release such a huge amount that it can be seen miles away” he says. He says it should be made mandatory for big cities to implement measures against light pollution.

Falcón adds that if the problem of light pollution is not addressed, it will eventually have a dramatic impact on species, including humans.

“A recent study has shown that artificial light is triggering a decrease in the population of nocturnal pollinating insects. This directly impacts the plants as the pollination is not correctly achieved. As the plant species decrease, the daytime active insects that rely on these plants are also decreasing, as they don’t get enough food to survive. It affects insects at night, plants and has a rebound effect on insects during the daytime too.”

According to Falcón, artificial light is impacting mammals too. “All the species are interlinked. When one element of the system gets impacted, the whole system starts feeling the effect. So even if the entire system doesn’t totally collapse instantly, studies show that this is likely to be the issue on a long term basis.”

https://arstechnica.com/?p=1822780