The World Without Us

Palmyra’s soft green lagoon is pure and lucid, its tropical splendor patiently erasing crumbled concrete slabs where thousands of sooty terns now roost. The tallest structure here, a former radar antenna, has rusted in half; within a few more years, it will disappear completely among the coconut palms and almond trees. If all human activity suddenly collapsed along with it, Sala believes that quicker than we’d expect, the reefs of the northern Line Islands could be as complex as they were in the last few thousand years before they were found by men bearing nets and fishhooks. (And rats: probably the onboard, self-reproducing food supply for Polynesian mariners who dared cross this endless ocean with only canoes and courage.)

“Even with global warming, I think reefs would recover within two centuries. It would be patchy. In some places, lots of large predators. Others would be coated with algae. But in time, sea urchins would return. And the fish. And then the corals.”

His thick dark eyebrows arch beyond the horizon to picture it. “In 500 years, if a human came back, he’d be completely terrified to jump in the ocean, because there would be so many mouths waiting for him.”

Jeremy Jackson, in his sixties, was the elder ecological statesman on this expedition. Most here, like Enric Sala, are in their thirties, and some are younger graduate students. They are of a generation of biologists and zoologists who increasingly append the word conservation to their titles. Inevitably, their research involves fellow creatures touched, or simply mauled, by the current worldwide peak predator, their own species. Fifty more years of the same, they know, and coral reefs will look very different. Scientists and realisrs all, yet their glimpse at how inhabitants of Kingman Reef thrive in the natural balance to which they evolved has only hardened their resolve to restore equilibrium—with humans still around to marvel.

A coconut crab, the world’s largest land invertebrate, waddles by. Flashes of pure white amid the almond leaves overhead are the new plumage of fairy tern chicks. Removing his sunglasses, Sala shakes his head.

“I’m so amazed,” he says, “by the ability of life to hang on to anything. Given the opportunity, it goes everywhere. A species as creative and arguably intelligent as our own should somehow find a way to achieve a balance. We have a lot to learn, obviously. But I haven’t given up on us.”

At his feet, thousands of tiny, trembling shells are being resuscitated by hermit crabs. “Even if we don’t: if the planet can recover from the Permian, it can recover from the human.”

With or without human survivors, the planet’s latest extinction will come to an end. Sobering as the current cascading loss of species is, this is not another Permian, or even a rogue asteroid. There is still the sea, beleaguered but boundlessly creative. Even though it will take 100,000 years for it to absorb all the carbon we mined from the Earth and loaded into the air, it will be turning it back into shells, coral, and who knows what else. “On the genome level,” notes microbiologist Forest Rohwer, “the difference between coral and us is small. That’s strong molecular evidence that we all come from the same place.”

Within recent historic times, reefs swarmed with 800-pound groupers, codfish could be dipped from the sea by lowering baskets, and oysters filtered all the water in Chesapeake Bay every three days. The planet’s shores teemed with millions of manatees, seals, and walruses. Then, within a pair of centuries, coral reefs were flattened and sea-grass beds were scraped bare, the New Jersey-sized dead zone appeared off the mouth of the Mississippi, and the world’s cod collapsed.

Yet despite mechanized overharvesting, satellite fish-trackers, nitrate flooding, and prolonged butchery of sea mammals, the ocean is still bigger than we are. Since prehistoric man had no way to pursue them, it’s the one place on Earth besides Africa where big creatures eluded the intercontinental megafaunal extinction. “The great majority of sea species are badly depleted,” says Jeremy Jackson, “but they still exist. If people actually went away, most could recover.”

Even, he adds, if global warming or ultraviolet radiation bleaches Kingman and Australia’s Great Barrier Reef to death, “they’re only 7,000 years old. All these reefs were knocked back over and over by the ice ages, and had to form again. If the Earth keeps getting warmer, new reefs will appear farther to the north and south. The world has always changed. It’s not a constant place.”