CSUSM professor in world's spotlight for ocean research

SAN MARCOS -- A Cal State San Marcos professor has published startling research showing that the ocean has been soaking up about half the carbon dioxide generated by humans since the dawn of the Industrial Revolution.

The North County university's Victoria J. Fabry and the international team of scientists she worked with found that carbon dioxide, or CO2, is changing the chemistry of the sea and may well be threatening ocean life.

The work has unraveled a scientific mystery over why so much more carbon dioxide has been generated than can be measured in the atmosphere. One researcher said the oceans can be said to have cut the effect of carbon dioxide warming in half.

The National Science Foundation said the work represented the first comprehensive study of the ocean's storage of carbon dioxide derived from human activity.

The culprit

Carbon dioxide, a colorless and odorless gas, is a product of respiration and combustion. Cement manufacturing and the burning of coal and other fossil fuels are among the chief ways human activity has added to the amount of CO2 in the atmosphere and in the sea.

As the carbon dioxide levels rise in the ocean, the seawater becomes more acidic. As the acid level increases, it may be more difficult for a score of ocean creatures -- including reef-building corals and a mollusk or snail known as the pteropod, which is a particular interest of Fabry's -- to calcify and form their protective shells.

And the calcium carbonate that those shells are made of, Fabry said, is the very substance that neutralizes the carbon dioxide as it dissolves in the seawater.

Fabry's study appears to confirm previous scientific models that found carbon dioxide to be concentrated in the upper 10 percent, perhaps the top 500 to 600 meters, of the oceans. The organisms the professor and her colleagues studied require light, and so are also plentiful in that upper strata of the sea.

Coral reefs at risk

The good news, Fabry said, is that without the ocean absorbing almost half the carbon dioxide that humans have poured into the atmosphere, the greenhouse effect and global warming could be far more severe.

"The bad news," Fabry added, "is that we're changing ocean chemistry … and that's serious. We're changing the chemistry of the seawater."

"It's a wake-up call," she said. "There are so many unknowns, but we think there is cause for concern and people should know."

Fabry said marine life is not likely to become extinct because of increasing carbon dioxide levels, but she said that life will shift from the colder waters of the north toward the equator. The shift may change the ecology of the ocean in unpredictable ways.

"If you like coral reefs, go see them now," said Fabry, a Carlsbad resident who joined the university faculty in 1993 and who in 2001 received the CSUSM president's award for innovation in teaching. "They're going to calcify less in the future and when a storm comes along, they're going to be weaker and break apart more readily. … Coral reefs are in trouble worldwide."

Marine chemist Andrew Dickson, an associate professor in residence at Scripps Institution of Oceanography in La Jolla who has a longtime interest in CO2 levels, said the research starts getting scientists "to the edge of this accounting" for what happens to the by-products of industrial activity.

"For the first time," he said in an interview Monday, "we're able to say that this much CO2 has ended up in the ocean. Before, we could just speculate."

Getting the word out

Fabry, the sole biological oceanographer on the faculty at Cal State San Marcos, joined two of the other five co-authors of the research last week at the American Association for the Advancement of Science in Washington, D.C.

They brought their message to a crowded press conference on the eve of publication of the findings in the July 16 issue of the association's weekly magazine, Science.

The news was quickly spread around the globe by far-flung organizations such as the BBC, Voice of America, The Associated Press and Reuters. Links pop off Google.com's news engine from keywords such as ocean and carbon dioxide.

The Science article carries the weighty title: "Impact of Anthropogenic CO2 on the CaCo3 System in the Oceans." Translation: How carbon dioxide generated by humans affects the formation of the shells of marine life, the shells that neutralize that very CO2 when they dissolve.

Ten years in the making

Based on a decade-long survey of the distribution of carbon in the world's oceans in the 1990s, the report was the result of the work of a team of scientists from Australia, Canada, South Korea, Spain, Germany and the United States. U.S. sponsors included National Oceanic and Atmospheric Administration, the National Science Foundation and the federal Department of Energy.

The researchers found that the level of carbon dioxide in the atmosphere generated by human activity has gone up some 36 percent since 1800, from 280 parts per million at the start of the Industrial Revolution to 380 parts per million today.

The levels of two centuries ago had long been established by other researchers who measured the CO2 in air bubbles within ice cores taken from the seas off Greenland and Antarctica.

The total taken up by the oceans over the years, said Christopher Sabine of the National Oceanic and Atmospheric Administration's Pacific Marine Environmental Laboratory in Seattle: Some 118 billion metric tons, almost half of it generated in the past two decades.

But for the fact that the ocean has taken up some 48 percent of the carbon dioxide generated by humans, the levels in the air would be far higher, perhaps around 435 parts per million. That much CO2 could have made the atmosphere much warmer than the one degree Celsius that's already occurred. The extremes of weather since that warming also could have become that much more dramatic, the researchers said.

"The oceans are producing this tremendous service to humankind by reducing the amount of carbon dioxide in the atmosphere, which can lead to global warming," Sabine, Fabry's colleague, told a July 15 press conference.

"But it's changing the chemistry of the oceans," he said, "and may have consequences for marine ecosystems."

Scientists traveled the world in ships, stopping in thousands of different spots in the oceans to measure temperature, saltiness, and levels of nutrients and elements such as oxygen and carbon. Fabry herself joined expeditions off the coast of Alaska, diving into water as frigid as 10 degrees Celsius -- "your hands shake it was so cold." she said -- to collect pterapods, chiefly the Clio pyramidata, for study.

At one point, she exposed the mollusks, which are about 5 to 7 millimeters in length, to 1,000 times the current level of carbon dioxide in the seawater. The result: Their shells dissolved within 48 hours. How fast, she asks, can these organisms change to cope with increasing levels of CO2 in the ocean?

In that vein, some studies report that CO2 levels in the atmosphere may increase to 700 or 800 parts per million by the end of the century if fossil fuel consumption continues its pattern of growth. If that happens, the studies report, marine life could lose 25 percent to 45 percent of the ability to produce protective shells. Less calcification could alter the food webs in the seas and change the diversity of the oceans.
