Oceans soaking up carbon dioxide
Scientists say water becoming acidic, endangering sea life
After absorbing nearly half of humankind's industrial emissions of carbon dioxide for the past 200 years or so, the Earth's oceans are becoming more acidic -- a chemical change that could significantly harm sea life and speed up global warming.
That's the gist of several reports in today's Science magazine from an international team led by researchers at Seattle's Pacific Marine Environmental Laboratory, operated by the National Oceanic and Atmospheric Administration.
Carbon dioxide is a so-called "greenhouse gas," and its atmospheric increase, largely because of fossil fuel use, is one of the main drivers of global warming. But only half of the total carbon dioxide produced by human activity has remained in the atmosphere. The rest has disappeared, and scientists, until now, have debated where it went.
It turns out "the oceans have done us a great service" by absorbing much of this carbon dioxide, said Christopher Sabine, an oceanographer at the Seattle NOAA station -- but at a price, other researchers say.
Sabine was principal investigator for the international research project that, for the first time, quantified just how much of the atmospheric carbon dioxide is being absorbed and recycled by the oceans.
Working with teams from elsewhere in the United States, Australia, Canada, Spain, Japan, South Korea and Germany, Sabine and others reviewed nearly 10,000 measurements of oceanic carbon concentrations worldwide taken on some 95 research cruises.
Using sophisticated methods to track how the atmospheric carbon is slowly absorbed and "processed" in the surface waters of the oceans, the scientists estimated that the oceans had taken up some 118 million metric tons of atmospheric carbon dioxide during the past two centuries -- about 48 percent of all fossil fuel emissions during the same time period.
"Their results show that the oceans store a major proportion" of the carbon dioxide produced by human activity, and provide a better understanding of the carbon cycle, said Columbia University's Taro Takahashi, who wrote a commentary on the findings in the journal.
Richard Feely, Sabine's colleague at the Seattle lab, was principal author of another report in today's Science that examined some of the chemical and biological impacts on the oceans acting as one of the primary carbon sinks for our industrial effluent.
"We are changing the chemistry of the oceans," said Feely. Carbon dioxide is an acid, he noted, and the oceans are becoming more acidic -- a chemical change that could potentially upset the entire marine ecosystem.
Continue reading this story from the Seattle P-I:
Oceans soaking up carbon dioxide
