A bleached coral near the Great Barrier Reef on 16 March 2017. Photo: Reuters

By Robinson Meyer
11 April 2017 (The Atlantic) – At about the same moment that millions of Americans sat staring at their television or laptop or phone—watching the results from the presidential election stream in, seeing state after state called for Donald Trump—Kim Cobb was SCUBA diving near the center of the Pacific Ocean. She did not watch the same trickle of news as other Americans. She surfaced, heard the results, and dove in the water again. She was, after all, attending to devastation. Cobb is a climate scientist at the Georgia Institute of Technology. On November 8, she was on her most recent of many research trips to Kiritimati Island reef, the largest coral atoll in the world. (Kirimati is pronounced like Christmas.) She first began studying the reef in 1997, during the last big El Niño warming event; she has returned nearly every year since. Last year, she went three times. “We had been waiting for the big one. And boy… did it happen,” she told me earlier this year. “It really rolled out at an unprecedented magnitude. This particular El Niño event had its maximum temperature loading almost in a bulls-eye almost around Kirimati Island.” By any measure, its caused a cataclysm. Eighty-five percent of the corals in the reef died: They will never recover, disintegrating into sand over the next several years. Two-thirds of the surviving corals bleached in some way, meaning they did not reproduce and may have sustained long-term damage. “Almost none of this reef has made it through 2015 and 2016,” Cobb said, calling the event “the wholesale destruction of the reef.” By any measure, 2016 was not a good year for coral reefs. El Niño raised ocean temperatures worldwide, devastating corals the world over. The Great Barrier Reef—the sprawling system off the coast of Australia, and among the world’s  most biodiverse reef systems—suffered a particularly debilitating year. Miles and miles of the coral reef bleached so severely, and for so long, that they died. On Monday, news broke that it happened again. For the second year in a row, warm ocean temperatures are bleaching the Great Barrier Reef. The white splotches of ocean floor indicative of the phenomenon run even farther south—some 500 kilometers—than they did last year. The bleaching occurred even though there is no worldwide El Niño this year: The reef is ailed not by a rare climatic phenomenon but by the baseline warming of the oceans. Until this decade, back-to-back bleaching events like that simply didn’t happen. “It’s new. It is so new. It’s a complete change in the phenomenon that all of us study,” said Ruth Gates, a professor at the Hawaii Institute of Marine Biology and the president of the International Society for Reef Studies. “We knew that this day would come—we’ve been seeing the thermal-tolerance threshold for corals get closer and closer, and we knew it was pushing over the limit for coral survival.” [more]

Ruins, Not Reefs: How Climate Change Is Fast-Forwarding Coral Science