Light pollution: an endangered starry sky

A new study based on more than 50,000 observations by citizens around the world reveals that dark skies are disappearing much faster than expected. And Quebec is no exception.

“The growth of light pollution is staggering. It is two to three times more than we thought,” says Cégep de Sherbrooke Professor of Physics Martin Aubé, who is aware of the results published in the prestigious journal. Flag several days ago.

The study in question shows that the night has become on average 10.4% brighter each year since 2011 in North America, according to 51,351 naked-eye observations of its participants.

“Honestly, I don’t think Quebec is an exception, except for some areas where efforts are being made,” says Remy Boucher, scientific coordinator of the Mont-Mégantic International Dark Sky Reserve.

Harmful street lighting

In Quebec, as elsewhere, this increased pollution is partly explained by the installation of street lamps equipped with LEDs (light emitting diodes) in cities and on roads.

It contains more blue light [que l’ancien éclairage jaune au sodium]which makes them even more harmful,” explains Martin Ope.

Their impact on light pollution has also been greatly underestimated in the past, as most of the satellites used to study Earth at night are “blind” by the blue light they emit.

“We have been able to demonstrate that citizen science is an important addition to previous measurement methods,” said Christopher Kyba, lead author of the study associated with the GFZ Geosciences Research Center, in a press release in Potsdam, Germany.

Goodbye Little Dipper

Today, many residents of large Quebec cities can no longer even admire the constellation Ursa Minor on a moonless night.

“There are only the brightest planets and stars left,” says Remy Boucher, who has long led introductory astronomy workshops.

Greenhouses are very shiny

The strong lighting of greenhouses, encouraged by the government with the goal of developing food independence in Quebec, also exacerbates light pollution.

For example, the orange glow from the Tondra greenhouses in Saint-Félicien (in Saguenay-Lac-Saint-Jean) can be seen for at least 80 kilometers.

“It hurts us when we want to observe the aurora borealis, in the north,” laments Claude Boivin, president of the local astronomy club, Borealid.

Finally, human and animal health is equally affected by light pollution, especially many nocturnal animals, as Professor Martin Oppé stresses.