Scientists from China, Australia, the United Kingdom, and the United States developed a new approach to evaluate the air-sea exchange component CO2, changes in which are directly connected to the variations in atmospheric CO2. They discovered that absorption of CO2 in the North Atlantic was about two times as efficient during the Last Glacial Maximum than the Holocene.
The outcomes of the study titled “More efficient North Atlantic carbon pump during the Last Glacial Maximum” have been published online in Nature Communications on May 15th, 2019.
This new estimate, related to geochemical data from multiple sediment cores, showed an extra ~100 gigaton sequestration of carbon by the North Atlantic during the Last Glacial Maximum, which is comparable to a decrease of ~50 ppm atmospheric CO2. This emphasizes a key role of the North Atlantic in carbon sequestration in the glacial deep ocean.
A greater high-latitude cooling and enhanced nutrient utilization could be responsible for more efficient glacial CO2 absorption in the North Atlantic, but further studies are required to figure out the exact mechanisms.
Jin Zhangdong, Professor, State Key Laboratory of Loess and Quaternary Geology (SKLLQG), Institute of Earth Environment, Chinese Academy of Sciences (IEECAS)
According to Dr Zhang Fei from SKLLQG, since it has long been suggested that the Southern Ocean is a significant region that influences atmospheric CO2 changes, the use of the new approach to estimate past air-sea CO2 exchange in the Southern Ocean has gained considerable attention.