The oceans are the planet’s most important depository for atmospheric carbon dioxide on time scales of decades to millenia. But the process of locking away greenhouse gas is weakened by activity of the Southern Ocean, so an increase in its activity could explain the mysterious warmth of the past 11,000 years, an international team of researchers reports.
The oceans are the planet’s most important depository for atmospheric carbon dioxide on time scales of decades to millenia. But the process of locking away greenhouse gas is weakened by activity of the Southern Ocean, so an increase in its activity could explain the mysterious warmth of the past 11,000 years, an international team of researchers reports.
The warmth of that period was stabilized by a gradual rise in global carbon dioxide levels, so understanding the reason for that rise is of great interest, said Daniel Sigman, the Dusenbury Professor of Geological and Geophysical Sciences at Princeton.
Scientists have proposed various hypotheses for that carbon dioxide increase, but its ultimate cause has remained unknown. Now, an international collaboration led by scientists from Princeton and the Max Planck Institute for Chemistry point to an increase in Southern Ocean upwelling. Their research appears in the current issue of the journal Nature Geoscience.
“We think we may have found the answer,” said Sigman. “Increased circulation in the Southern Ocean allowed carbon dioxide to leak into the atmosphere, working to warm the planet.”
Read more at Princeton University
Image: Danny Sigman, the Dusenbury Professor of Geological and Geophysical Sciences at Princeton University, helped lead an international team of researchers who identified Southern Ocean upwelling as the key to the mysterious warmth of the Holocene, the 11,000-year interglacial period when agriculture and human civilization flourished. (Credit: Laura Pedrick)
