Ice-free Arctic Not Very Effective as Carbon Sink
03.08.2010 - Atmosphere & Space, Water & Oceans, Ice & Snow, Arctic
While researchers in past years suggested a melting Arctic Ocean could be an ally in the struggle against rising levels of carbon dioxide, new research published in the journal Science shows this may not be the case. The results of a survey conducted in the waters of the Canada Basin show the Arctic Ocean’s potential as a carbon sink to be extremely restricted. The reason for this, according to the researchers, is that in the absence of ice, carbon dioxide in the water quickly reaches an equilibrium with the atmosphere.
In a joint effort with the government of China, an international team of scientists embarked on the Xue Long (Snow Dragon) for a three-month research voyage in the summer of 2008. Through techniques such as direct sampling of water and “underway” sampling, the team studied the upper layers of the waters into which they sailed. In addition, they made several measurements of the waters’ salinity, temperature, nutrient concentration and chlorophyll activity. What the team found was rather unsettling: the greater areas of ice melt observed each summer significantly reduce the Canada Basin’s potential as a CO2 sink, mainly due to the rapid uptake of the greenhouse gas from the atmosphere.
Since the Industrial Revolution, levels of carbon dioxide in the atmosphere have skyrocketed, almost 30 % of which has been absorbed by the oceans. The downside, however, is that the uptake of carbon dioxide in the oceans has led to ocean acidification, causing changes in conditions for the growth of all life forms. The discovery, while both intriguing and disappointing, shows us that “[…] we can’t expect the oceans to do the job of helping offset global warming in the short term”, said lead author Wei-Jun Cai, a professor at the Department of Marine Biology at the University of Georgia’s Franklin College of Arts and Sciences.
