Southern Ocean Carbon Sink

From NASA’s Earth Observatory:

If you drove to work or school this morning or used electricity to power the computer on which you’re looking at this image, chances are you released carbon dioxide, a greenhouse gas, into the atmosphere. According to the Intergovernmental Panel on Climate Change, people released about 7.8 billion tons (7.8 gigatons) of carbon into the atmosphere in 2005 by burning fossil fuels and making cement, and that number grows every year. What happens to all of the carbon dioxide that people release into the atmosphere? About half stays in the atmosphere, where it warms Earth, and the other half is absorbed by growing plants on land and by the ocean.

As people have put more and more carbon dioxide into the atmosphere, the ocean has responded by soaking up more carbon dioxide—a trend scientists expected to continue for many years. But in 2007, a team of scientists reported in the journal Science that between 1981 and 2004 carbon dioxide concentrations in the Southern Ocean didn’t change at all, even though global atmospheric levels continued to rise. This graph shows the changes scientists expected to see (blue line) compared to their estimate of actual carbon dioxide absorption (red line). The results suggested that the Southern Ocean was no longer keeping pace with human carbon dioxide emissions.

Why has the Southern Ocean started to lag behind human emissions? The answer, believes Corinne Le Quéré, is in the wind. An ocean scientist at the University of East Anglia, Le Quéré led the study that discovered the Southern Ocean’s change of pace. Le Quéré modeled the mechanisms that influence how the ocean takes up carbon and found that winds increased between 1981 and 2004. Winds stirred the ocean and enhanced the upwelling of deep, carbon-rich water. The ocean releases carbon dioxide into the atmosphere in areas where deep water comes to the surface, so increased upwelling allowed the ocean to vent more carbon dioxide. This increased venting made it look like the Southern Ocean was no longer taking up carbon dioxide as quickly as people were pumping it into the atmosphere.

Full article and references are available at: Southern Ocean Carbon Sink

Related Links:

• Southern Ocean already losing ability to absorb CO₂

• Oceans, Where Life Started, Are Dying – Part IV :  Researchers found evidence of corrosive water about 20 miles off the west coast of North America from Canada to Mexico.

• Human carbon emissions make oceans corrosive : ‘Carbon dioxide spewed by human activities has made ocean water so acidic that it is eating away at the shells and skeletons of starfish, coral, clams and other sea creatures …’

• The Eight Steps that Help Kill More of Our Fish : How Your Car’s Exhaust Emissions Helps Create Dead Zones and Kill Our Fish.

• Global warming could starve oceans of oxygen: study : Areas of the eastern Atlantic and Pacific Oceans with low amounts of dissolved oxygen have expanded in the past 50 years, apparently in line with rising temperatures.

• The Floating Toxic Garbage Island : A patch of garbage twice as large as the continental United States and dubbed the Great Pacific Garbage Patch floats in the middle of the Pacific Ocean in North Pacific Gyre.
• Oceans, Where Life Started, Are Dying – Part III : Tourism: The Most Destructive Human Activity After Warfare

• Oceans, Where Life Started, Are Dying – Part II : Major Problems: Fertilizer Runoff; Tourism; Coastal Developments [and Ocean Warming due to climate change]

• Oceans, Where Life Started, Are Dying – Part I : Our Oceans Are Now Dying!