Researchers are reexamining the role of the southern ocean's biological pump in driving atmospheric CO2 levels during the holocene period. Studies suggest various factors, including changes in ocean upwelling, earth's obliquity, and glacial-interglacial periods, may have contributed to fluctuations in atmospheric CO2. The exact mechanisms and drivers of these changes are still being explored, with some research pointing to the importance of biological pump efficiency, ocean carbon storage, and air-sea disequilibrium during glacial periods.