4 October 2018: A group of researchers have published an article that assesses 13 global and local ocean-based measures to reduce climate change and its impacts on marine ecosystems and ecosystem services. The article finds high potential for ocean-based options to address climate change and its impacts.

In the article titled, ‘Ocean Solutions to Address Climate Change and Its Effects on Marine Ecosystems,’ the researchers state that current emission pledges under the Paris Agreement on climate change are insufficient to limit the global temperature rise to below 2°C and to reach SDG targets. They observe that reductions in greenhouse gas (GHG) emissions are possible through shifting from fossil fuels to renewable energy, improving energy efficiency, protecting and enhancing natural carbon sinks, and implementing carbon capture and storage (CCS) at the point of carbon dioxide generation, among other possible solutions. The authors argue that relatively little attention has been paid to ocean-based actions in comparison with land-based actions. Within this context, they investigate the potential of various ocean-based actions to reduce the magnitude and rate of ocean acidification, ocean warming and sea level rise as well as their impacts on marine ecosystems and ecosystem services based on eight environmental, economic, technological and social criteria.

Improved international governance mechanisms can ensure coherency in ocean-based climate action.

The authors find that the greatest climate benefit would result from combining global and local solutions, some of which could be implemented immediately. Renewable energy is one such example. The article cautions that some measures are too uncertain to be recommended without more research. Such measures include albedo enhancement, alkalinization and cloud brightening.

In addition, the researchers recommend achieving political consistency through effective cross-scale governance mechanisms and focusing on co-benefits, disbenefits, effectiveness and cost effectiveness. They stress the need for “improved international governance mechanisms to ensure coherency in ocean-based climate action.”

The researchers note that all measures have tradeoffs associated with them. Global measures typically showed high potential to address climate-related challenges but had potentially large collateral effects while local measures had multiple co-benefits but were insufficient to provide adequate solutions globally. As an illustration, local measures such as protection and pollution reduction score high on governability and co-benefits but are less effective in moderating changes in climate-related drivers. For example, conserving mangroves and seagrasses can help the ocean to better absorb carbon dioxide (CO2) and provide co-benefits for fisheries and water filtration; however, its potential to address climate impacts at a global level is low because there are limited ocean areas with vegetated habitats. Conversely, alkalinization scores low in global governability and technological readiness but high in global mitigation potential. The authors argue therefore that multiple measures will need to be implemented to achieve a pathway consistent with the aims of the Paris Agreement and the SDGs.

The article was published in Frontiers in Marine Science and is a product of The Oceans Solutions Initiative, an expert group supported by the Prince Albert II of Monaco Foundation, the Ocean Acidification International Coordination Centre of the International Atomic Energy Agency (IAEA), the Veolia Foundation and the French Facility for Global Environment. [Publication: Ocean Solutions to Address Climate Change and Its Effects on Marine Ecosystems] [Ocean Action Hub News Article]