TURN OFF THE LIGHT

What’s lost when darkness becomes endangered?

- ADAM GOPNIK

The Luxor Hotel’s powerful “sky beam” confuses flying creatures drawn to the light.

Among the many looming ecological disasters that terrify us today, one that only a handful of people have contemplated as sufficiently looming and terrifying is the loss of the bats in our belfry. According to “The Darkness Manifesto” (Scribner), by the Swedish ecologist Johan Eklöf, most churches in southwest Sweden had bat colonies back in the nineteen-eighties, and now most of them don’t. Light pollution, his research suggests, has been a major culprit: “District after district has installed modern floodlights to show the architecture it’s proud of, all the while the animals—who have for centuries found safety in the darkness of the church towers and who have for 70 million years made the night their abode—are slowly but surely vanishing from these places.”

The presence of bats in the belfry, as a metaphor for disordered thinking, is usually taken to refer to the way bats would flutter around the upper stories of distressed churches, but a larger madness, Eklöf thinks, is responsible for their absence. A professor at Stockholm University, he is an expert in bats, which might suggest a