Carbon emissions raise Arctic acidity levels

Washington — The Arctic Ocean covers roughly 9 percent of the Earth’s surface and its chemistry is changing, growing more acidic in ways that will affect marine ecosystems.

The world’s oceans dwarf the continents. The planet may be called Earth, but water dominates the globe, covering 70 percent. The oceans are also swallowing down big gulps of the excess carbon dioxide pumped into the atmosphere through the use of carbon-based fuels.

“In my mind there is no doubt about the acidification of the oceans, and they are changing very, very fast,” said oceanographer Jón Ólafsson from the University of Iceland, who has been studying the world’s northernmost waters for 30 years. “It’s really amazing how clear the signal is, how fast the uptake [of carbon dioxide] is.”

While Ólafsson regards ocean acidification as a fact beyond dispute, the process varies in both degree and cause in the many different oceanic regions. He points out that the fluctuation of pH levels in the oceans is a natural seasonal process. Still, factors related to global warming — increased carbon dioxide absorption and melting sea ice — definitely are involved in the accelerated change, he said.

Ólafsson spoke May 6 as part of a scientific panel at the Arctic Ocean Acidification Conference in Bergen, Norway. The conference was organized by the Arctic Monitoring and Assessment Programme (AMAP), the research division of the Arctic Council.

Eight nations with shores on the Arctic Ocean formed the council in 1996 to promote cooperation among the peoples and interests of the region. As the effects of climate change present themselves most dramatically in the polar regions, the council’s attention has been focused increasingly on environmental issues.

AMAP has released a three-year assessment of Arctic Ocean acidification trends, which will be presented to the Arctic Council at a May 14-15 meeting in Kiruna, Sweden. Secretary of State John Kerry will represent the United States at the meeting.

The AMAP report on acidification notes that the Arctic is particularly sensitive to the process because carbon dioxide is more readily absorbed into cold water, and the increasing amounts of fresh water surging into the Arctic from rivers and melting ice diminish its capacity to neutralize acidification.

An environmental change of this magnitude will certainly affect marine life, from plankton to fish, AMAP reports in a findings summary. But how and to what degree remains unknown.

When environmental factors put stress on the natural balance of an ecosystem, “it is never good news,” said biologist Sam Dupont from the University of Gothenburg, Sweden, who served on the panel with Ólafsson.

He said the effect of acidification on Arctic life forms can’t be predicted with the current level of knowledge, and biologists must work to “understand the mechanisms of species response.”

Impact on marine ecosystems will also have consequences for the some 4 million inhabitants of the globe’s northernmost regions.

“Arctic Ocean acidification has the potential to affect both commercial fisheries that are important to northern economies,” the AMAP summary says, “and marine resources that are used by Arctic indigenous people.”

Ólafsson suggests that an interdisciplinary approach involving oceanographers, chemists, biologists and economists will be necessary to begin to predict what will result from increasing acidification in the Arctic.

Reports on biodiversity, Arctic pollution and sustainable development will also be reviewed by the Arctic Council in the May 14-15 session.

Charlene Porter,, 13 May 2013. Article.

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