Greenhouse gas is changing ocean ecosystems.

• Author: Serikawa, Kyle
• Position: Biodevastation

The oceans have buffered the effects of man-made carbon dioxide in the atmosphere, but at a potential cost to the organisms living in the oceans' upper layers. Scientists at the Pacific Marine Environmental Laboratory on Sand Point Way are part of an international team who discovered that half of the carbon dioxide produced by human industry has ended up in the oceans instead of remaining in the air. They reported their findings last year in the journal Science.

Their research represents the culmination of a 15-year effort to measure and interpret the role of the ocean in the global carbon cycle.

Over the past two centuries, although the amount of man-made carbon dioxide in the atmosphere has steadily increased, only about half of the expected increase was seen. Where the other half went was unknown.

These studies represent "the first time we've taken direct measurements to show that the oceans take up man-made carbon dioxide," says Dr. Chris Sabine, one of the primary authors on the reports. Dr. Richard Feely, another of the lead authors, adds: "These numbers are used to constrain the global carbon cycle models. We need to have these constraints to know if the models are working properly."

Building accurate models for the movement of carbon dioxide is of particular importance because carbon dioxide acts as a greenhouse gas. As the amount of carbon dioxide in the atmosphere increases, more of the heat from the sun is trapped near the earth's surface, potentially leading to an increase in average temperatures around the world.

This research also demonstrated the effects of carbon dioxide uptake on the oceans themselves. "People seem to have very strong feelings about global warming," says Sabine. "But whether you believe in global warming or not, we are adding huge amounts of carbon dioxide to the atmosphere, and that is measurably changing the chemistry of the oceans."

Carbon dioxide's potential to affect the environment was recognized over a century ago by the Swedish chemist Svante Arrhenius in 1896. Since then, scientists have struggled to accurately measure and model the global carbon cycle--the movement of carbon dioxide into and out of the many components of the environment such as the forests and the oceans, as well as the man-made inputs from burning fossil fuels, cutting down forests, and producing cement.

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Carbon dioxide also deserves particular attention because it has an extremely long retention time in the...