Among the many threatening environmental disasters, one that few have recognized as dire enough is the death of bats.

According to Swedish ecologist Johan Eklöf’s book Manifesto of Darkness, around four decades ago most churches in southwest Sweden were filled with colonies of bats, which is no longer the case.

In his study, he claims that one of the main culprits for this is light pollution.

“Site after site has been installing state-of-the-art lighting to show off the architecture they are proud of, while animals that have hid for centuries in the safety of the darkness of church spiers and that have made the night their home for 70 million years. “Slowly but surely they are disappearing from these places,” he notes.

A professor at Stockholm University and a specialist in bats, the only mammals capable of flying, Eklöf in his book considered how artificial light affects animal species and how humanity’s relationship with darkness proved problematic.

The term “light pollution” began to be used by astronomers in the late 1960s, today the word refers to the constant and intense light pollution emitted by cities after dusk, which blocks the view of the stars and turns the night sky a sickly orange color. -grey.

By 2016, 80% of the world’s population – and 99% of the population of the US and the Old Continent – were living under a light-altered night sky. Today, a third of the world’s population cannot see the galaxy even on the clearest night. However, this phenomenon of light pollution has far more serious consequences than stargazing.

Rich nightlife

On the pages of his book, Eklöf recalls the obvious, but forgotten, how the night gives life and mobilizes beingsequipped with large, infrared-sensitive eyes that see what we can’t, and protected by darkness, act in ways we can only imagine.

For example, we learn that male butterflies mate once and then die. Females bear and lay their eggs in the fields, and then they also die. These creatures, which play a key role in pollination and maintaining the balance of ecosystems, are threatened by artificial light, which confuses them, says Eklöf.

As he explains in The Darkness Manifesto in breathtaking if terrifying detail, All living organisms follow circadian rhythms sensitive to light, which, if disturbed, lead to a range of problems, from disorientation, which many species rely on for survival, to mass mortality.

Hatching sea turtles are confused by the glare of the city and head inland rather than out to the moonlit sea. City trees, embarrassed by artificial lighting, remain greener than those in the countryside. On an Australian island, the light disorganized wallabies to the point where they gave birth much later than usual, when food had already run out. Even corals disorganized by artificial light reduce their reproduction and lead to bleaching, scientists say.

But light is affected not only by the creatures of the animal world, but also by plants and humans. Our eyes have a hard time adjusting to the dark and our night vision which is protein activated. rhodopsin in the retina, it takes time to work. Now cities such as Singapore and Hong Kong are so brightly and continuously lit that their inhabitants hardly use night vision. As their rhodopsin becomes redundant, it atrophies, and over the years it is possible that their offspring will lose this pigment protein and stop seeing in the dark, even in moderate light.

Source: New Yorker/New York Times.