To understand the enormous threats facing the world’s oceans, Colin Woodard—the 31-year-old author of Ocean’s End: Travels Through Endangered Seas (Basic Books)—suggests looking no farther than the Republic of the Marshall Islands, which is only halfway around the world, in the mid-Pacific.

By any definition, the Marshalls are an unusual place. Before gaining independence a few years ago, the collection of coral atolls and sandy islands was overseen by the United States, following Japanese occupation during World War II. The islanders soaked up American culture at warp speed. “As one fellow who lived out there put it, the islands lost the best things about their culture and took the worst things from ours,” Woodard says. “They eat too many processed foods like Cheez-Whiz and Coke, and their metabolisms haven’t adjusted, so they have enormous rates of diabetes.” Moreover, the densely packed islands are laden with piles of trash that have nowhere else to go. “Coconut husks rot away, but now it’s cans and cars and washing machines. They’re gorgeous islands, but the ones near human settlements are covered in rusting debris.”

Here’s the kicker: The islands average only 6 feet above sea level, yet some scientists expect ocean levels to rise by 1 to 3 feet over the coming decades. Even the islanders’ traditional last resort—climbing up palm trees to wait out severe storms—won’t wash, so to speak, in that scenario. “Given storms and erosion, the scientists’ best estimate is that the country will cease to exist during the next century,” Woodard says. “What they told me sounded very similar to what I heard when I was growing up—that a nuclear holocaust seemed entirely possible, yet there was absolutely nothing that could be done about it. The tenet of the environmental movement, that you should think globally and act locally, will not be enough for the Marshall Islands.”

Woodard, who lives in D.C. when he’s not globe-trotting, picked up an affection for the ocean while growing up in Maine. But the environmental issues really hit home while Woodard was spending the early ’90s as a stringer in post-Soviet Eastern Europe. Though communications technologies were often poor and his sources were reticent from years of “justified paranoia,” it became painfully clear to him how serious the damage was to bodies of water such as the Danube River, which drains half the continent into the Black Sea. “It went through a biochemical disaster—the Black Sea essentially collapsed,” he says. “It was a huge story—and shockingly underreported in the international news media.”

After leaving Eastern Europe, Woodard came home to pitch the idea for his book. During two years of research, he visited Newfoundland, Belize, the Mississippi River, and other far-flung locales to do his reporting. One of Woodard’s favorites was the Antarctic region, where he spent six weeks working out of an ice-breaking scientific vessel. In southern Chile, he was amazed to discover a line of penguins singlemindedly tromping over him as he reclined, inadvertently, in their ages-old path to and from the sea. “I was cynical when I first went—I said there was no way I was going to laugh at the cute little penguins,” he recalls. “But I learned that they are hilarious in everything they do.” —Louis Jacobson