Rising Acidity in World’s Ocean Waters 100 Years Earlier than Predicted

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Climate models predicted it wouldn't happen until the end of the century. So Seattle researchers were stunned to discover that vast swaths of acidified sea water are already showing up along the Pacific Coast as carbon dioxide from power plants, cars and factories mixes into the ocean. In some places, including Northern California, the acidified water was as little as four miles from shore.

"What we found ... was truly astonishing," said oceanographer Richard Feely, of the National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory in Seattle. "This means ocean acidification may be seriously impacting marine life on the continental shelf right now." The phenomenon is an aspect of global warming scientists are just beginning to understand.

Acidified ocean water can be fatal to some fish eggs and larvae. It also interferes with the formation of shells and skeletons, harming corals, clams, oysters, mussels and the tiny plankton that are the basis of the marine food web. "Their shells dissolve faster than they are able to rebuild them," said Debby Ianson, an oceanographer at Fisheries and Oceans Canada and a co-author of the study published today in the online journal Science Express.

Since the Industrial Revolution, when humans began pumping massive amounts of carbon dioxide into the atmosphere, the oceans have absorbed 525 billion tons of the greenhouse gas, Feely estimates. That's about a third of the man-made emissions during that time. By reducing the amount of carbon dioxide in the atmosphere, the oceans have blunted the temperature rise due to global warming. But they've suffered for that service, with a more than 30 percent increase in acidity.

"This is another example where what's happening in the natural world seems to be happening much faster than what our climate models predict," said Carnegie Institution climate scientist Ken Caldeira, whose work suggested it would be nearly 100 years before acidified water was common along the West Coast. And there's worse to come, the scientists warn. The acidified water upwelling along the coast today was last exposed to the atmosphere about 50 years ago, when carbon-dioxide levels were much lower than they are now. That means the water that will rise from the depths over the coming decades will have absorbed more carbon dioxide, and will be even more acidic. "We've got 50 years' worth of water that's already left the station and is on our way to us," study co-author Hales said. "Each one of those years is going to be a little bit more corrosive."

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Images courtesy of Dana Greeley & Simone Alin, PMEL, and Daily Mail

Original Source: Seattle Times