Acid oceans: The 'evil twin' of climate change

These foragers of the sanctuary's frigid waters, flipping in and out of sight of California's coastal kayakers, may not seem like obvious beneficiaries of a climate treaty crafted in the Danish capital. But reducing carbon emissions worldwide also would help mend a lesser-known environmental problem: ocean acidification.

"We're having a change in water chemistry, so 20 years from now the system we're looking at could be affected dramatically but we're not really sure how. So we see a train wreck coming," said Andrew DeVogelaere, the sanctuary's research director, while out kayaking this fall with a reporter in the cold waters.

Nothing in the treaty negotiations specifically addresses the effects of carbon absorption in the oceans on marine life, which studies show is damaging key creatures' hard shells or skeletons.

Oceans absorb about 25 percent of the world's greenhouse gases pumped into the atmosphere from human activities each year, says a new U.N. report released at the Copenhagen talks this week. That helps slow global warming in the atmosphere, the focus of the Copenhagen talks.

But carbon dissolving in oceans also forms carbonic acid, raising waters' acidity that damages all manner of hard-shelled creatures, and setting off a chain reaction that threatens the food chain supporting marine life, including the lumbering sea mammals along the 276-mile coast of the California sanctuary and the rest of the U.S. West Coast.

By 2100, the report said, some 70 percent of cold water corals — a key refuge and feeding ground for commercially popular fish that also are food for the seals and otters — will be exposed to the harmful effects.

Ocean acidity could increase 150 percent just by mid-century, according to the report by the Secretariat of the U.N. Convention on Biological Diversity.

"This dramatic increase is 100 times faster than any change in acidity experienced in the marine environment over the last 20 million years, giving little time for evolutionary adaptation within biological systems," it said.

The average acidity of oceans' surface water is estimated to increase measurably by the end of the century and will affect marine life, according to Peter Brewer, a senior scientist at the Monterey Bay Aquarium Research Institute.