Carbon leakage under the Southern Ocean could have warmed the planet for 11,000 years – Brinkwire

A "leak" of carbon in the Southern Ocean has gradually warmed the planet for 11,000 years, researchers have discovered.

They say the leak comes from a "biological pump" known in the Southern Ocean.

Researchers now believe that an increase in ocean circulation in the region has triggered the gas leak.

Fossil nitrogen to create a model for the activity of the Southern Ocean during the Holocene, a period that began about 11,000 years ago.

Measurements of fossil – derived nitrogen isotopes indicate that during the Holocene, increasing amounts of water, rich in nutrients and carbon dioxide, rose from the sea. deep ocean up to the surface of the Southern Ocean.

Although the cause of the increase in upwelling is not yet clear, the most likely process seems to be a change in the 'Roaring 40', a belt of winds blowing toward the 39 are surrounding Antarctica, say the researchers.

The oceans are the world's largest deposit for atmospheric carbon dioxide at time scales of decades to millennia.

But the process of locking greenhouse gases is weakened by the activity of the Southern Ocean. Explain the mysterious heat of the last 11,000 years, an international team of researchers.

The heat of this period has been stabilized by a gradual increase in global levels of carbon dioxide, so that understanding the reason for this rise is of great interest. Daniel Sigman, Dusenbury Professor of Geological and Geophysical Sciences at Princeton.

Scientists have proposed various hypotheses for this increase in carbon dioxide, but its ultimate cause has remained unknown.

Now an international collaboration led by scientists from Princeton and the Max Planck Institute of Chemistry indicates an increase in the upwelling of the Southern Ocean.

Their research appears in the current issue of Nature Geoscience.

think we may have found the answer, "Sigman said.

" Increased circulation in the Southern Ocean has allowed carbon dioxide to escape into the atmosphere. atmosphere, helping to warm the planet. "

" Danny brings a whole new perspective to a long-standing issue, "said Wallace Broecker, a professor of geology at Columbia University, who said

"As the Southern Ocean acts as an accelerator in the transfer of CO2 between the ocean and the atmosphere, we must thank Danny because we now know that the throttle was at work during what was considered a rest period. 19659002] Discoveries on ocean change may also have implications for predicting how global warming will affect ocean circulation and how much atmospheric carbon dioxide will increase due to the burning of fossil fuels.

Sigman and his colleagues found that an increase in the upwelling of the Southern Ocean could be responsible for stabilizing the climate of the Holocene, the period reaching over 10,000 years before the industrial revolution.

"In this context, the increase of 20 ppm observed during the Holocene may seem weak," Sigman said.

"However, scientists believe that this small but significant increase played a key role in preventing the progressive cooling of the Holocene, which may have facilitated the development of complex human civilizations." [19659002TheresearchersstudiedthreetypesoffossilsfromseveraldifferentregionsoftheSouthernOcean:diatomsandforaminiferatwoshellmicroorganismsfoundintheoceansanddeep-seacorals

According to isotope ratios of nitrogen trace organic matter trapped in the mineral walls of these fossils, scientists have been able to reconstruct the evolution of nutrient concentrations in the waters of surface of the Southern Ocean over the last 10,000 years.

Measurements of fossil – derived nitrogen isotopes indicate that during the Holocene, increasing amounts of water, rich in nutrients and carbon dioxide, rose from the sea. deep ocean up to the surface of the Southern Ocean.

Although the cause of the increase in upwelling is still unclear, the most likely process seems to be a change in the "Roaring 40", a belt of winds blowing toward the air. is surrounding Antarctica.

Oceanic upwelling, the weakened biological pump during the Holocene, allowed more carbon dioxide to escape from the oceanic depths into the atmosphere and hence from the ocean. 39; explain the increase of 20 ppm atmospheric carbon dioxide. carbon dioxide to invade back into the atmosphere, "said Sigman.

"We are essentially drilling holes in the membrane of the biological pump."

The same processes are at work today: The absorption of carbon by the ocean slows the increase in atmospheric carbon dioxide produced by fossil fuels and the upwelling of the Southern Ocean still allows some of this carbon dioxide to fall back into the atmosphere.

• If the Holocene results can be used to predict how the upwelling of the Southern Ocean will change in the future, improve our ability to predict the changes in atmospheric carbon dioxide and therefore in the global climate, "said Sigman.