Ocean-based solutions for climate action

What is the potential of the ocean and its ecosystems to reduce the causes and impacts of climate change?


Anne-Sophie Garrigou

The Beam’s editor-in-chief, Anne-Sophie Garrigou, reports from COP25 in Madrid


“The world’s ocean and cryosphere have been taking the heat from climate change for decades and the consequences for nature and humanity are sweeping and severe,” says Hans-Otto Pörtner, Co-Chair of the IPCC. The global ocean is warming, acidifying and losing oxygen, and sea levels are rising. As a result, an important number of species and ecosystems — think coral reefs, seagrass meadows and kelp forests — are endangered. The situation will only worsen by the end of this decade, even if we manage to fully reach the goals of the Paris Agreement on time.

“We are in a very critical period and we are not seeing policy moving towards reducing emissions,” says Pörtner. Experts and scientists here at COP25 in Madrid stress that scaling up of efforts towards ambitious mitigation and adaptation is imperative. The ocean is a key element of our life support system and provides many services. Coastal and marine ecosystems act as sinks and reservoirs of greenhouse gases. By contributing to the negative emission efforts, the global ocean offers opportunities to reduce the causes and consequences of climate change, both globally and locally. That is if great efforts are made to conserve and protect ocean ecosystems.

Pörtner says, “today, ocean use is unsustainable”, and ocean-based measures for mitigation and adaptation have received relatively little attention in climate discussions. Fortunately, the science community has come up with policy recommendations about ocean-based measures to enhance global mitigation and local coastal adaptation. Aimed at supporting climate policies, these measures are meant to address the causes of climate change, support biological and ecological adaptation, enhance societal adaptation and solar radiation management.

“Marine renewable energy, carbon capture and storage, pollution reduction, community-based adaptation, conservation, restoring and enhancing habitats, restoring and increasing coastal vegetation, relocating and diversifying economic activities, relocating people, enhancing open ocean productivity, are few examples of those ocean-based measures,” says Jean-Pierre Gattuso, Senior Research Scientist at CNRS.

“These ocean-related measures should not be considered as a substitute for climate mitigation on land, which must also be strongly pursued for the benefit of the atmosphere as well as the ocean,” explains the experts.

Costa Rica wants to place itself as a leader in ocean protection

Haydée Rodríguez Romero, Vice-minister of Water and Seas of Costa Rica, introduces Costa Rica’s decarbonisation plan, which, when implemented, will make Costa Rica one of the world’s first decarbonized countries. She says, “We know this is our responsibility. We want to demonstrate that we can have economic growth without having emissions. We are aware that if we want to achieve this goal and the Sustainable Development Goals, we need to start talking about nature-based solutions.”

Forest, oceans, mangroves are part of those nature-based solutions. And in Costa Rica, mangroves are a key element of the decarbonisation plan. “We need to talk about the blue economy. We need to emphasizes why people need to protect these mangroves. And we cannot talk about a blue economy if we don’t recognize the importance of those ecosystems for the people,” explains the minister.

Nature-based solutions come in addition to reducing greenhouse gas emissions

“The best thing we can do for the ocean is to drastically reduce GHG emissions so we need countries here at COP25 to increase their ambition and we need it now” recalls Lorely Picourt, Secretary General of Ocean and Climate Platform, an organisation that promotes reflection and exchanges between the scientific community, civil society and political decision-makers.

Policies relating to biodiversity must recognize the major role of the ocean in the face of the climate crisis and global changes, and the Ocean and Climate Platform has worked on a set of policy recommendations for a healthy ocean. On mitigation, Picourt explains the importance of reducing GHG emissions to maintain marine life’s good health. It is the only option to mitigate ocean warming, acidification, deoxygenation, sea-level rise, impacts of extreme weather events and destruction of particularly sensitive ecosystems, such as coral reefs. The organisation recommends the development of marine renewable energy while preserving ocean biodiversity.

“Science is absolutely crucial. We need to invest more and enhance scientific research and we need to increase scientific collaboration, not only between countries but between scientific disciplines as well” adds the expert. More recommendations on adaptation of marine ecosystems and vulnerable communities to climate change and on sustainable finance (raising funds for ocean projects, increase financial resources dedicated to the ocean, etc.) are also available for policymaker in this report, which concludes with a call to decision maker to end subsidies to fossil fuel production immediately and accelerate the implementation of adaptation measures, in particular for island states and coastal regions, favouring nature-based solutions.


IDDRI Policy Brief: https://www.iddri.org/en/publications-and-events/policy-brief/opportunities-increasing-ocean-action-climate-strategies


Policy recommendations of the Ocean and Climate Platform “A healthy ocean, A protected climate”: https://ocean-climate.org/wp-content/uploads/2019/11/mep-plaidoyer-ENG-WEB-1.pdf