During the last 14,000 years, especially throughout the Antarctic Cold Reversal (ACR), extensive winter sea ice followed by spring melting created ideal conditions for Phaeocystis algae to flourish, absorbing large amounts of CO₂ and contributing significantly to climate regulation.

Research shows that algal blooms in the Southern Ocean during this period played a crucial role in reducing atmospheric carbon dioxide levels, highlighting their importance in past climate change mitigation.

A recent study published in Nature Geoscience used sedimentary ancient DNA from a core near the Antarctic Peninsula to reveal that microalgae like Phaeocystis were key in absorbing CO₂ during the last 14,000 years, especially during the ACR.

The findings underscore the importance of integrating DNA analysis with geological methods to better understand past climate events and the ecological roles of organisms like Phaeocystis in carbon cycling.

Future research should focus on improving DNA and geological analysis techniques and studying key species to enhance predictions of climate shifts and ecological changes.

Phaeocystis blooms contributed to biogeochemical cycles by affecting nutrient distribution, supporting food webs, and increasing carbon transport to ocean depths, which played a role in global climate regulation.

Today, ongoing sea ice loss threatens Phaeocystis populations, potentially reducing oceanic carbon sequestration and disrupting cloud formation due to decreased DMS gas production, thereby possibly exacerbating climate change.

Sediment analysis during the ACR indicated increased organic carbon input driven by heightened biological productivity and nutrient-rich meltwater from sea ice expansion.