The European Marine Board has warned that oceans cannot absorb enough carbon dioxide to achieve net zero emissions, stressing that only greater spending and stronger regulation will keep global warming below 1.5C this century, reports Norwegian SciTech News.

The report, released at COP30 in Brazil, said marine carbon dioxide removal technologies are not mature enough to be deployed at scale. Helene Muri of the Norwegian Institute of Air Research said oceans can play a role but only with safeguards and verifiable impacts.

Proposed methods include cultivating seaweed, fertilising phytoplankton, restoring coastal ecosystems, enhancing ocean alkalinity and using electrochemical extraction. But Dr Muri cautioned that none can yet guarantee long-term sequestration or measurable results.

The study emphasised that cutting fossil fuel emissions remains essential. Dr Muri said renewable energy sources such as solar and wind can replace carbon-intensive power, though sectors like aviation and shipping will still produce residual emissions.

According to the Intergovernmental Panel on Climate Change, reaching the 1.5C target requires net negative emissions, with 5-10 gigatons of CO2 removed annually by the end of the century. Global emissions stood at 42.4 gigatons in 2024, CICERO data showed.

UN Secretary General Antonio Guterres told COP30 leaders that overshooting the 1.5C limit by the early 2030s is inevitable but reversible. He called the threshold a red line for humanity, urging governments to act with proven tools to cut emissions.