Above is a good primer on ocean acidification narrated by Dan Laffoley of the International Union for Conservation of Nature (IUCN). The video spans the vulnerable corals of Australia's Great Barrier Reef to the equally vulnerable shellfish industry of the Pacific Northwest, detailing the potential effects of a more acidic ocean.
To those unfamiliar with global warming's "evil twin", the video does a good job of explaining the basics of ocean acidification: simply put, carbon dioxide reacts with ocean water to make carbonic acid. The ocean absorbs about a quarter of civilization's carbon dioxide emissions, and as a result they are now 30 percent more acidic than before the industrial revolution. What does this mean for animals like clams, corals, or oysters that rely on a more stable pH range to build their calcium carbonate skeletons and shells?
Mother nature has provided some of her own experiments, as documented in the video. Near Vesuvius in the Mediterranean carbon dioxide bubbles up from below, rendering a glimpse in to a future, more acidic, and bleaker ocean. Closer to the vents, where the water is more saturated with carbon dioxide, the communities of life become less diverse and invasive algaes thrive.
Off of Australia, the Great Barrier Reef is already struggling in the new man-made environment. As more and more acidic water continues to erode the corals in the coming decades, these ecosystems of otherworldly beauty and diversity could simply go extinct.
Perhaps most worrisome of all is the effect of acidification on pteropods, a shell forming plankton at the very bottom of the ocean's food web, nicknamed the "potato chips of the sea". These animals are especially vulnerable to acidification, and as the narrator ominously intones: "If their shells dissolve a critical part of the food web dissolves with them".
Learn more about ocean acidification and what you can do to help.