Research suggests that the North Pacific biological pump played a role in a plateau of atmospheric carbon dioxide levels during the Bølling-Allerød period. The exact mechanisms and factors contributing to this phenomenon are being studied, with some research indicating that changes in ocean ventilation, nutrient loads, and air-sea CO2 disequilibrium may have been involved. The relationship between the ocean's biological pump and atmospheric carbon dioxide levels is complex and still being reappraised, with different regions and factors potentially having varying impacts.