10 November, 2026

Antalya, Türkiye

As governments gather for UNFCCC climate negotiations COP31 in Antalya, civil society groups, Indigenous Peoples groups, grassroots movements, and climate justice organisations from around the world are warning against growing efforts to promote marine carbon dioxide removal (mCDR), also called marine geoengineering, under the guise of ‘Ocean Climate Solutions’ and ‘Ocean Climate Technologies’.

Mary Church from CIEL said, “The focus on the critical role the Ocean plays in regulating the climate system must not be used to justify its dangerous manipulation. Geoengineering marine ecosystems in an attempt to remove carbon dioxide from the atmosphere would pose profound and unprecedented risks to an already over exploited and rapidly heating ocean, while doing nothing to tackle the root causes of the crisis.” 

With the world approaching a breach of the critical 1.5°C temperature threshold, proponents of these highly speculative and risky technologies are increasingly positioning the Ocean for managing carbon emissions. Yet, rather than addressing the root causes of the climate crisis, these proposals risk turning the Ocean into a testing ground for dangerous interventions, with potentially far-reaching consequences for marine ecosystems, biodiversity and communities.

Aaklauk Adrienne Blatchford, Indigenous Environmental Network said, “Indigenous People of the Arctic rely on the Ocean for our food security, our cultural survival, and our spiritual practices. As stewards of the land and waters in the North, we reject false climate solutions that allow the expansion of the fossil fuel and critical mineral industry. These harmful projects will not only perpetuate climate disasters and climate refugees, but devastate a critical ecosystem that the world depends on.”

This warning comes as ocean heating, acidification, and sea level rise are already stressing marine ecosystems. "At a time when the Ocean is already under immense pressure from over-exploitation, pollution and climate change, we cannot allow it to become the next frontier for geoengineering experimentation and corporate profit. The same extractive economic model that has brought the climate system to the brink of collapse is now presenting the manipulation of ocean ecosystems as a climate solution. We need ocean protection, not ocean manipulation," added Kwami Kpondzo, Global Forest Coalition.

Marine carbon dioxide removal technologies including ocean fertilisation, ocean alkalinity enhancement, biomass sinking, etc., have not demonstrated effective, safe and durable carbon removal at the scale required to influence the climate system. 

At the same time, the proposed scale of interventions is staggering. Ocean fertilisation and ocean alkalinity enhancement could involve dispersing materials across 10–20% of the Ocean's surface. Biomass sinking could compete for more than half of the world's coastline, while direct ocean capture would require processing thousands of cubic kilometres of seawater, with the potential to harm or kill marine life in the process. The consequences would not stop at national borders as ocean currents, marine ecosystems and food webs are interconnected, making large-scale marine geoengineering inherently transboundary.

Civil society groups are concerned about attempts to use the Paris Agreement's carbon market mechanisms under Article 6 to legitimize marine geoengineering technologies and experiments that are subject to existing international governance restrictions. Coraina de la Plaza, Hands Off Mother Earth (HOME) Alliance added, “Governments must prioritize genuine ocean protection and ocean ecosystem restoration, respect existing restrictive international governance frameworks, like the long-standing CBD moratorium on geoengineering, and reject false solutions that put the Ocean at further risk.”

“The expansion of marine geoengineering in climate negotiations comes with huge risks. Its actual impacts on the oceanic ecosystem and what it would also mean for geopolitical ramifications, are underplayed by proponents. At COP31, UNFCCC must recognise the precautionary principle to geoengineering and that real solutions do exist to address climate change,” added Kaveri Choudhury, ETC Group.

Additional Information

1. Home Alliance COP31 Statement On Marine Geoengineering Experiments
2. Home Alliance COP31 Briefing On Marine Geoengineering Experiments
3. Press Release: Blue Economy And Marine Geoengineering Threats – Stop Commodifying, Experimenting And Exploiting Our Oceans
4. Geoengineering Governance: Restrictive Framework Must Be Upheld and Strengthened 
5. Geoengineering Projects Tracker 

About Hands Off Mother Earth (HOME) Alliance

The Hands Off Mother Earth (HOME) Alliance is a driving force in the fight against the growing threat of large-scale technological manipulation of the climate and biodiversity: geoengineering. We are an international civil society network of close to 200 organizations from over 45 different countries, from the Global South and the Global North. HOME was first launched as a global campaign in April 2010 at The World People’s Conference on Climate Change and the Rights of Mother Earth in Cochabamba, Bolivia. Follow us: Website| LinkedIn | Instagram | Bluesky |  X | YouTube

For media enquiries please contact
Neha Gupta 

Communications Coordinator, Hands Off Mother Earth (HOME) Alliance

comms@handsoffmotherearth.org