Keep The Night Sky Dark

While sunlight gives electricity for the lights we need, there can be too much of a good thing. Thanks to Lisa Abend at the New York Times for this review:

A Manifesto for Loving the Darkness, and Not Metaphorically

Light pollution is disruptive to many species, from corals to bats to the humans who put up all those lights. “The Darkness Manifesto” urges us to reconsider our drive to dispel the dark.

Artificial lights disorient many species, including the grasshoppers that swarmed the powerful lights over the Las Vegas strip in 2019. Bridget Bennett/Agence France-Presse — Getty Images

Losing a connection to the night sky is losing our connection to nature, said Johan Eklöf, but it is also losing some of our history. “What we see now is the same sky as our ancestors were looking at and making up stories about.” Nora Lorek for The New York Times

The zoologist Johan Eklöf began to consider the disappearance of darkness in our brightly lit world in 2015, when he was out counting bats in southern Sweden. The surrounding grounds were dark, as they had been decades earlier when his academic adviser had tallied the bat populations in the region’s churches. In the intervening years, however, those churches — whose belfries are famously appreciated by the winged mammals — had been illuminated with floodlights. “I started to think, how do the bats actually react to this?” Eklöf says.

The short answer: Not well. Together with his adviser, Jens Rydell, Eklöf launched a new bat census and discovered that in 30 years — the average bat’s life span — fully half the area’s colonies had disappeared.

That research soon led Eklöf to investigate how other species are affected by artificial lighting — including the species responsible for installing floodlights in churchyards. The resulting book, “The Darkness Manifesto,” which came out in English from Scribner on Feb. 14, is a wide-ranging exploration of humanity’s troubled relationship with darkness, and the damaging effects of our drive to overcome it.

Astronomers first began using the term “light pollution” in the 1960s, and today it most often refers to the persistent glow that emanates from cities after dusk, blocking out the stars and tinting the night sky an orangish-gray. By 2016, a full 80 percent of the global population — and 99 percent of the population in the United States and Europe — lived under light-polluted skies.

Earlier this year, a study published in the journal Science found that between 2011 and 2022, light pollution on Earth increased 9.6 percent annually. “It really shook my faith,” says Christopher Kyba, a researcher at the German Research Center for Geosciences and lead author of the study, of the dramatic results. “I had been quite an optimist that with newer technology, things were going to get better, because lights are better designed. But instead what we saw is that most countries are getting brighter.”

Today, one-third of the world’s people cannot see the Milky Way, on even the clearest night. But the impact of all that light goes far beyond impeded stargazing. As “The Darkness Manifesto” explains in fascinating — if terrifying — detail, all living organisms are governed by light-sensitive circadian rhythms that, if disrupted, can unleash effects that range from an impaired sense of direction (pity the poor dung beetle, who, unable to see the stars that help it navigate, can’t get its nutrient-rich ball of excrement home) to mass executions (witness the fate of the swarm of grasshoppers that, drawn by the beam shooting from the Luxor casino, descended on Las Vegas in 2019, only to end up like so much lifeless confetti cluttering the Strip).

As anyone who has ever watched moths circle the porch light endlessly can attest, artificial bulbs can be fatal to insects. “Many of them die before dawn, sometimes of sheer exhaustion,” Eklöf writes. Even those that survive “haven’t achieved their night’s goals. They haven’t gotten their nectar (and transported the plants’ pollen around), haven’t found a partner, and haven’t laid any eggs.”