January 10, 2024/Kiel. The ocean plays a crucial role in the storage of carbon dioxide (CO2). The so-called marine biological carbon pump is an important research topic in this context. However, according to Dr Ivy Frenger, climate researcher at the GEOMAR Helmholtz Centre for Ocean Research in Kiel, a key component is often overlooked. In an opinion paper, she and international colleagues outline why it is insufficient to focus solely on biological processes when investigating the accumulation of CO2 in the ocean by the biological carbon pump. They argue that the co-occurrent return of CO2 to the atmosphere through ocean circulation must also be considered.