By Abbas Nazil
A report released during the COP30 warns that oceans could play a role in absorbing carbon dioxide, but current marine carbon removal technologies are not ready for large-scale deployment.
Experts emphasize that emissions reductions remain the most reliable and urgent method to limit global warming and meet the 1.5°C target set under the Paris Agreement.
Marine carbon dioxide removal methods rely on the ocean’s natural capacity to store carbon, with approaches ranging from enhancing plankton and seaweed growth to chemical or physical techniques that extract CO2 directly from seawater.
Once captured, carbon can be stored in deep-sea sediments, geological formations, or long-lasting products, but uncertainties remain regarding the effectiveness and permanence of these storage methods.
Helene Muri, senior researcher at the Norwegian University of Science and Technology and leader of the European Marine Board expert group, stressed that rigorous monitoring, reporting, and verification systems must be established before scaling any ocean-based carbon removal.
The report highlights that storing carbon in the ocean complicates governance, verification, and long-term tracking due to dynamic marine conditions, making oversight far more challenging than land-based carbon removal methods.
Despite these challenges, marine carbon removal may become necessary to address residual emissions from sectors difficult to decarbonize, such as aviation and shipping, and to achieve net-zero and net-negative emission targets by mid-century.
Field trials are underway, but methods remain in early development stages, and large-scale implementation without proper safeguards risks environmental harm and undermines credibility.
Researchers stress that oceans cannot serve as a “miracle fix” and urge that immediate global action prioritize cutting emissions, while marine carbon removal strategies are carefully studied, regulated, and transparently managed.
The report underscores that carbon removal technologies must complement—not replace—direct emissions reductions to ensure climate targets remain achievable and oceans are protected for future generations.