WASHINGTON — With the oceans absorbing more than 1 million tons of carbon dioxide an hour, a National Research Council study released Thursday found that the level of acid in the oceans is increasing at an unprecedented rate and threatening to change marine ecosystems.
The council said the oceans were 30 percent more acidic than they were before the Industrial Revolution started roughly 200 years ago, and the oceans absorb one-third of today's carbon dioxide emissions.
Unless emissions are reined in, ocean acidity could increase by 200 percent by the end of the century and even more in the next century, said James Barry, a senior scientist at the Monterey Bay Aquarium Research Institute in California and one of the study's authors.
"Acidification is changing the chemistry of the oceans at a scale and magnitude greater than thought to occur on Earth for many millions of years and is expected to cause changes in the growth and survival of a wide variety of marine organisms, potentially leading to massive shifts in ocean ecosystems," Barry told the Senate Commerce Committee's Oceans, Atmosphere, Fisheries and Coast Guard Subcommittee on Thursday.
Also testifying was actress Sigourney Weaver, who made passing references to her roles in "Alien" and "Avatar" while urging Congress to pass global climate change legislation.
The hearing came on the 40th observance of Earth Day, an anniversary noted by the subcommittee's chairwoman, Sen. Maria Cantwell, D-Wash.
"We know that this is changing the very chemistry of our oceans," Cantwell said. "And while the full implications of these changes aren't clear, the initial signs are frightening."
The effects of growing ocean acid levels might be more pronounced off the coast of the Pacific Northwest. Cold water absorbs more carbon dioxide than warm water does. A phenomenon known as "upwelling" off the coast of Washington state and Oregon also brings deep ocean water — which already is more acidic — to the surface, where it's saturated with even more carbon dioxide. According to one study, upwelling of acidified water off the West Coast had reached levels that hadn't been anticipated until 2050.
Shellfish growers and commercial fishermen from the Gulf of Alaska to the Gulf of Mexico are worried.
"This is a devastating ghost lurking in the shadows that would change our whole lives," said Donald Waters, a commercial fisherman who fishes for red snapper and king mackerel out of Pensacola, Fla.
The National Research Council report, requested by Congress, said carbon dioxide emissions were increasing so rapidly that natural processes in the sea that maintained pH levels couldn't keep up. PH is a scale used to measure acid or alkaline levels, with 7 being neutral. The average pH of ocean surface waters has moved from 8.2 to 8.1 and while that not might seem a lot, scientists are concerned.
"Like climate change, ocean acidification is a growing global problem that will intensify with continued carbon dioxide emissions and has the potential to change marine ecosystems and affect benefits to society," the report said.
The report called for an expanded system to monitor ocean conditions and for increased research into ocean chemistry and the impact that changes would have. Scientists think that increased acidity could affect the entire marine food chain, from microscopic forms of phytoplankton to fish and whales.
The Environmental Protection Agency is investigating whether it can use the Clean Water Act to control greenhouse gas emissions because of ocean acidification.
Not everyone is convinced that rising acid levels would be devastating.
John Everett, a former scientist with the National Oceanic and Atmospheric Administration who's now a consultant on ocean issues, told the subcommittee that the oceans will remain alkaline even as they absorb more carbon dioxide.
Everett said that rainwater, which absorbs carbon dioxide as it's falling, is 100 times more acidic than ocean water is. He also assured beachgoers that their feet won't dissolve when they enter the water.
"It doesn't look like it is a problem," Everett said. "I don't see damage."
Barry said Everett was engaging in a game of semantics, adding that if the oceans are becoming less alkaline they are becoming more acidic.
"All the predictions I have seen, even the more conservative, say we will see significant changes," Barry said.
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