Acidified Ocean Water Rising Up Nearly 100 Years Earlier Than Scientists Predicted

Tweet

End portion below; whole thing here: http://seattletimes.nwsource.com/html/localnews/2004431933_webacidocean22m.html

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.

Until now, researchers believed most of the acidified water was confined to the deep oceans.

But during ship-based surveys last year, Feely and his colleagues found the natural upwelling that occurs along the West Coast each spring was pulling the acidified water up onto the continental shelf.

"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."

Some creatures, like jellyfish, actually thrive in more acid waters. Adult mussels have a protective coating that may protect their shells.

But many other species are likely to suffer, including commercially important fish like pollock and salmon, which could see their food supply diminish.

"I think this is a red flag for us, because it's right at our doorstep on the West Coast," said Victoria Fabry, a biological oceanographer at California State University San Marcos who was not involved with the study. "It's telling us that we really need more monitoring to figure out what's going on."