A recent report from the Norwegian University of Science and Technology highlights significant risks associated with scaling up marine carbon dioxide removal technologies. Released during the COP30 climate conference in Brazil, the findings emphasize that current methods for utilizing oceans to absorb carbon are not sufficiently reliable or safe for large-scale application.
Experts warn that while the ocean’s natural capacity for carbon absorption presents a potential solution for mitigating climate change, existing technologies require rigorous monitoring and verification before implementation. The report, issued by an expert panel under the European Marine Board, underscores the urgency of addressing emissions reductions as the world nears the critical 1.5°C temperature threshold.
Helene Muri, a senior researcher at NILU and NTNU, led the evaluation group and stated, “This is about safeguarding the oceans for a common good. The oceans can be part of the climate solution, but we need to strengthen the way we safeguard them before we scale things up.”
The report outlines various marine carbon removal strategies, including enhancing biological processes like plankton growth and employing chemical techniques to extract carbon dioxide from seawater. Once captured, carbon can be stored in deep-sea sediments or geological formations. Yet, the effectiveness and safety of these methods remain uncertain.
During his opening remarks at the COP30 Leaders’ Summit on November 6, UN General Secretary António Guterres stressed the critical nature of the climate crisis, stating, “Science now tells us that a temporary overshoot beyond the 1.5°C limit… is inevitable.” He called for immediate action, emphasizing that proven methods for reducing emissions must take precedence.
The European Marine Board report highlights the need for immediate focus on established approaches for emission reductions. Muri pointed out, “We know how to cut emissions, and we have lots of methods that work. That has to take top priority.”
Despite the push to reduce emissions, some sectors remain challenging to decarbonize. For instance, the aviation industry has yet to find a viable path to carbon-free flight. To achieve climate goals, countries are aiming for net-zero emissions by 2050, which necessitates balancing any remaining emissions through carbon removal methods.
Muri noted that achieving the 1.5°C target will require net negative emissions, which involves removing significant amounts of carbon dioxide from the atmosphere. According to scenarios from the IPCC, approximately 5 to 10 gigatons of CO2 must be removed annually by century’s end to meet these goals. In 2024, global CO2 emissions were recorded at 42.4 gigatons, according to the CICERO research institute.
While several marine carbon removal methods are being tested, many remain in early stages of development. Establishing robust standards for monitoring and verifying these methods is crucial. Muri explained the complexities involved, stating, “If you’re storing it in the ocean… it’s a lot harder to govern it and monitor it.”
As companies and governments explore carbon removal technologies, the potential for carbon credits raises additional concerns. Muri cautioned that without reliable verification systems, the integrity of these methods could be compromised. “If we want to be serious about figuring out if you can do marine carbon dioxide removal in responsible ways… we have to get serious about the monitoring, reporting, and verification aspects,” she stated.
Looking to the future, Muri acknowledged the necessity of exploring marine carbon removal despite its uncertainties. She emphasized that while these methods are not a “miracle ocean fix to climate change,” they could play a role in achieving ambitious climate targets. “We don’t know all the threats of these immature methods yet,” she said, urging for clear standards to be established before scaling up operations.
In summary, the report calls for a cautious approach to marine carbon removal, prioritizing proven technologies and rigorous oversight. As climate change accelerates, the world must navigate these complexities to safeguard both the planet and its oceans.
