The United Nations released a dire warning for the world’s coral reefs last month: Even if global warming is limited to 2 degrees Celsius, almost all reefs will “degrade,” according to the Intergovernmental Panel on Climate Change’s (IPCC) latest oceans report.
As reef health declines, everything from biodiversity of millions of species to tourism will be impacted. Heatwaves over the past 20 years have killed or bleached corals across nearly all reefs listed as World Heritage sites in places such as Hawaii, the Galapagos Islands and Australia. In 2016 and 2017, half of all corals died in the Great Barrier Reef in one of the most harrowing back-to-back bleaching events ever seen.
It’s not just warmer oceans though that puts corals at risk. As seas absorb more carbon dioxide they become more acidic. This, in turn, corrodes calcium carbonate, the core ingredient of corals. Industrial chemical runoff from farms, lawns and golf courses also hurts reefs.
This summer, some scientists gained hope that a giant “raft” of floating pumice rock spotted near Australia could help replenish the Great Barrier Reef. Scientists think the Manhattan-sized mass of volcanic rocks could help transport new colonies of barnacles, corals and other organisms to help replenish the reef.
But given moments like these only happen about once every five years, researchers are also working on a whole host of other initiatives to save our world’s reefs.