Strategies of marine plankton ecosystems to cope with climate change and their role in Ocean Negative Carbon Emissions (ONCE)

Current climate issues pose major challenges to human survival and development, with CO₂ recognized as the main driver of climate change. The ocean, as Earth's largest carbon sink, plays a vital role in the global carbon cycle, with Ocean Negative Carbon Emissions (ONCE) being a crucial pathway. Plankton, encompassing most marine primary producers and lower trophic-level consumers, are central to marine ecosystems and highly sensitive to climate change. Understanding their role in ONCE requires insight into their responses to ocean acidification and warming. These stressors influence plankton both at the cellular level-by altering biochemical processes-and at the community level-through adaptive differences and cascading ecological effects. Plankton responses may, in turn, generate feedbacks to the climate system. However, existing studies predominantly focus on individual species, lacking comprehensive cross-taxonomic comparisons. This review evaluates the effects of warming and acidification on diverse plankton groups, systematically analyzing their response mechanisms and potential climate feedbacks across multiple dimensions. The goal is to enhance understanding of the interactive processes between planktonic ecosystems and climate change, offering insights into their ecological functions and roles in shaping future carbon dynamics.