What’s known as a “global bleaching event” occurs when coral reefs in three oceans—the Atlantic, the Pacific, and the Indian—exhibit signs of heat stress all at the same time. There was a global bleaching event in 1998, and a second one in 2010. In October, 2015, the National Oceanic and Atmospheric Administration announced that another event was beginning. The bleaching continued through 2016, and then on through the first half of 2017. By the time it ended, in June of last year, almost a third of the shallow-water corals on the Great Barrier Reef were dead. In the northern stretches of the reef, the mortality rate was closer to three-quarters.

As it happens, shortly before NOAA’s announcement, Irus Braverman, a professor of law and geography at the University at Buffalo, set out to interview coral biologists. The earlier global bleaching events, combined with various other forms of destruction—disease, dredging, dynamite fishing—had already convinced marine scientists that reefs were in grave trouble. Still, as Braverman relates in her forthcoming book “Coral Whisperers: Scientists on the Brink” (University of California), even the gloomiest were caught off guard by the third event. After taking an aerial survey of the Great Barrier Reef, one of Australia’s most prominent coral biologists, Terry Hughes, showed the results to his students. “And then we wept,” he tweeted.

An American scientist, Laurie Raymundo, reported on Facebook that, after observing the devastation of reefs in Tumon Bay, on Guam’s west coast, “for the first time in the fifty years I’ve been in the water, I cried for an hour, right into my mask.”

Coral reefs are often referred to as living structures; as such, they span the divide between the faunal and the geological. Individual corals are tiny, gelatinous animals infelicitously referred to as polyps. In their cells, polyps house even tinier algae, which they rely on for food, to help fuel their extraordinary building projects. Bleaching occurs when water temperatures rise more than two degrees or so above normal. For reasons that are not entirely understood, corals react to the heat by expelling their symbionts. (Alternatively, according to some scientists, it’s the algae that respond by decamping.) If the bleaching event is short-lived, the corals can survive and, eventually, recover. But in a warming world, where such events are becoming both more frequent and more protracted, the prognosis for reefs is much the same as it is for sea ice.

A coral ecologist named Peter Sale, who’s a professor emeritus at Ontario’s University of Windsor, tells Braverman that reef scientists are confronting “the likely disappearance of the ecosystem they have been studying.” What most interests Braverman, though, is not the fate of reefs—with Sale, she takes their disappearance as likely—but the way scientists choose to “narrate” the crisis. She finds them divided into two camps. In one are those who argue that reefs’ downward spiral can be arrested only by dealing with climate change, which is to say, by completely revamping the world’s energy systems. (It’s worth pointing out that, if Wadhams and Serreze are right about Arctic feedbacks, even this may not be enough.)

“A lot of what we’re doing in terms of conservation actions is futile until we stabilize the climate,” Ove Hoegh-Guldberg, the director of the Global Change Institute, at Australia’s University of Queensland, tells Braverman. Hoegh-Guldberg describes local efforts to preserve or restore reefs as “rearranging the chairs on the Titanic to get a better view.” Imitating those on the other side, he says, “Let’s just block out those horrible people, like me, who say it’s all futile. ‘Lalalalalala, can’t hear you!’ ”

In the second camp are those who argue that, yes, reefs are dying and, yes, the situation is only going to get worse, but this just makes local restoration efforts that much more urgent. Ruth Gates, the director of the Hawaii Institute of Marine Biology, is working on selectively breeding corals that might be able to withstand higher temperatures, an approach that’s become known as “assisted evolution.”

“The gloom and doom is paralyzing,” she tells Braverman at one point. “The scope of climate change is paralyzing.”

“I don’t know what the outcome of our project will be,” Gates says at another point. But, on some level, “we’re already successful. Because we’re sending out a more hopeful message, something we can do actively.”

Hope and its doleful twin, Hopelessness, might be thought of as the co-muses of the modern eco-narrative. Such is the world we’ve created—a world of wounds—that loss is, almost invariably, the nature writer’s subject. The question is how we relate to that loss. Is the glass ninety-five per cent empty or is it five per cent full?

The message that there’s still “something we can do actively” has a lot to be said for it. It offers a rationale for not giving up—on species, on whole ecosystems—which is also a rationale for continuing to research these subjects and, perhaps most relevant for scientists turned authors, for continuing to write about them. Narrating the disaster becomes a way to try to avert it. Wadhams ends “A Farewell to Ice” with a chapter titled “A Call to Arms.” In it, he urges readers to “adopt every possible measure that will reduce unnecessary energy use,” to lobby for better laws, and to embrace nuclear power, which, he writes, “will keep the lights on without carbon emission.”

But we seem to have reached the point where even the calls to arms are starting to sound like dirges. In the same chapter in which Wadhams argues for better energy policies, he observes that such policies probably can’t—and almost certainly won’t—be put in place fast enough to save the Arctic. Therefore, he says, technologies to block sunlight or change the reflectivity of clouds will have to be deployed. These so-called geoengineering technologies have yet to be tested—if truth be told, they’ve really yet to be invented—but without them, according to Wadhams, the “temperature rise, and the associated further feedbacks, will be too great to allow our civilization to continue.” Apparently, this is supposed to count as inspirational.

It’s hard to say what purpose would be served by a message of straight-up despair; despondency, as it’s often noted, produces its own feedback loop. And yet, scientifically speaking, what alternative is there, as we move into the future, beyond the baiji, and the golden toad, and the reefs, and the sea ice, on toward reëngineering the atmosphere? Lalalalalala, can’t hear you! ♦