Ocean Acidification Update

Oceans' Growing Acidity Alarms Scientists
By Les Blumenthal
McClatchy Newspapers

Sunday 16 December 2007

Washington - Seven hundred miles west of Seattle in the Pacific at Ocean Station Papa, a first-of-its-kind buoy is anchored to monitor a looming environmental catastrophe.

Forget about sea levels rising as glaciers and polar ice melt, and increasing water temperatures affecting global weather patterns. As the oceans absorb more and more carbon dioxide and other greenhouse gases, they're gradually becoming more acidic.

And some scientists fear that the change may be irreversible.

At risk are sea creatures up and down the food chain, from the tiniest phytoplankton and zooplankton to whales, from squid to salmon to crabs, coral, oysters and clams.

The oceans are already 30 percent more acidic than they were at the beginning of the Industrial Revolution, as they absorb 22 tons of carbon dioxide a day. By the end of the century, they could be 150 percent more acidic.

"Everything points to dramatic effects," said Richard Feely, an oceanographer with the National Oceanic and Atmospheric Administration in Seattle. "There are suggestions the entire ecosystem could change over time."

Originally, scientists thought the oceans could be one of the solutions to the buildup of greenhouse gases, as they absorb about one-third of the carbon dioxide that's emitted worldwide. But they now know that the fundamental chemistry of the oceans has changed, and the possible impacts seem to grow more nightmarish as research accelerates.

"It seems like it is a one-way street, and that is alarming," said Steven Emerson, a professor of oceanography at the University of Washington. "The pH of the oceans could be lowered permanently."

[. . .]

Though cuts in carbon dioxide and other greenhouse-gas emissions might slow or reverse global warming, scientist say it could take thousands of years or longer to reverse the increased acidity of the oceans.

"For all practical purposes this is permanent," Emerson said. "That's not true of temperature. But with ocean acidification the time scales are long."