Published 25 February 2026
The ocean absorbs around 25% of carbon dioxide from human activities, but a new report warns that more research is needed to understand how the ocean carbon sink is changing.
CSIR chief researcher Dr Sandy Thomalla is one of 72 co-authors of the Ocean Carbon Research Report, which was launched by the Intergovernmental Oceanographic Commission (IOC) of United Nations Educational, Scientific and Cultural Organization (UNESCO) on Monday, 23 February 2026. The report highlights critical uncertainties around how much carbon the ocean absorbs and outlines priority areas for international scientific collaboration.
“Leading the section on the changing role of biology in the ocean carbon cycle brought home just how complex the ocean’s biological carbon processes are,” says Thomalla. “It also highlighted how much we still need sustained observations and coordinated research to understand how marine ecosystems will influence future carbon storage in the ocean.”
The report provides a roadmap to close these knowledge gaps. A clearer understanding is essential, because if the ocean absorbs less carbon in the future, more carbon dioxide remains in the atmosphere.
This leads to accelerated global warming, and the impact would cascade across coastal communities, ecosystems and global climate policy.
UNESCO’s roadmap specifically calls for integrated global ocean-observing tools, including satellites and sensors. Improved climate and ocean models, increased capacity in under-monitored regions and stronger collaboration between scientists, socio-economists and policymakers are also needed.
“I felt genuinely proud to contribute to an IOC programme supporting the UN Ocean Decade, which represents a global effort to deepen our understanding of the ocean’s role in climate and sustainability,” says Thomalla.
Thomalla is a career oceanographer who currently leads the CSIR-hosted Southern Ocean Carbon-Climate Observatory.
Read the full report: https://unesdoc.unesco.org/ark:/48223/pf0000397333.locale=en