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This field of melting ice in the Arctic's Canada Basin was the subject of a new study on carbon dioxide sinks led by UGA's Wei-Jun Cai.
Now, though, in research just published in the journal Science and led by a University of Georgia biogeochemist, that idea may be one more dead end. In fact, a survey of waters in the Canada Basin, which extends north of Alaska to the North Pole, shows that its value as a potential carbon dioxide "sink" may be short-lived at best and minor in terms of what the planet will need to avoid future problems.
The carbon dioxide level in the Earth's atmosphere has increased dramatically since the industrial revolution, and around 30 percent of that CO2 has been absorbedby the oceans. That has been the good news. The bad news is that it increases the acidification of the seas, causing changes in conditions for the growth of all life forms.
What Cai and colleagues found was that as greater areas of ice melt each summer, the Canada Basin's potential as a CO2 sink will diminish dramatically mainly because of the rapid uptake of CO2 from the atmosphere. And because of this carbon dioxide uptake, the waters become quite acidic and "a poor environment for calcium-carbonate shell-bearing marine organisms," Cai said.
The findings are at once intriguing and disappointing because carbon dioxide and other gases dissolve more readily in cold water than warm water, and so scientists had long thought that seas of melting polar ice would at least have the trade-off of being good places for the absorption of carbon dioxide.
Collaborative work of this kind between the governments of the United States and China on Arctic research is relatively new. Cai said it greatly benefits both parties.
"One of the take-away lessons of this research is that we can't expect the oceans to do the job of helping offset global warming in the short term," said Cai.
Cai's work is supported by the National Science Foundation and the National Oceanic and Atmospheric Administration.