Two projects led by researchers from UC San Diego’s Scripps Institution of Oceanography have been awarded nearly $2.5 million by the National Oceanic and Atmospheric Administration (NOAA) to probe the potential of climate change solutions aimed at fighting ocean acidification and removing planet-warming carbon dioxide from the atmosphere.
The projects are led by Scripps scientists Andreas Andersson and Andrew Dickson, respectively.
The awards are part of $24.3 million in funding, $14 million of which comes from the Inflation Reduction Act, to advance research on marine carbon dioxide removal strategies, marking the first large-scale public investment on research in this area. Despite the ocean’s large potential to store carbon, there are many unknowns about the scalability, effectiveness and cost of marine carbon dioxide removal strategies, and their possible social and ecological impacts. These projects will expand understanding of various aspects of marine carbon dioxide removal, and the potential associated benefits and risks.
Andersson’s project, which was awarded $1.45 million, will explore the potential of three seaweed farms operating in Florida and Japan to capture carbon and mitigate ocean acidification.
Dickson’s project, which was awarded just under $1 million, will develop and test a system that captures carbon dioxide from a mixture of gases – such as the exhaust from a gas-fired power station – and converts it into a mixture of salts that, when added to the ocean, stimulates seawater’s ability to absorb carbon dioxide via a process known as ocean alkalinity enhancement.
NOAA also funded 15 other marine carbon removal projects on behalf of the National Oceanographic Partnership Program for 2023 as part of its Ocean Acidification Program.
Seaweed solutions
Ocean seaweed farming shows promise as a nature-based solution that can capture carbon dioxide and fight ocean acidification in local waters. Andersson and his team are looking to test how much carbon can really be captured by seaweed cultivation. They also want to quantify the potential benefits and risks to marine life such as shellfish and corals that are susceptible to acidification.
“Learning more about [seaweed farming’s] carbon uptake capacity and ocean acidification mitigation potential is an important endeavor in the context of marine carbon dioxide removal,” said Andersson. “Seaweed cultivation offers many potential benefits to both marine and human communities. It has a rich history in many Asian countries with an extensive knowledge base of best practices and potential environmental impacts.”
In Florida, the researchers will study the potential co-benefits of culturing seaweed with shellfish side-by-side, which might strengthen ecosystem resilience. When seaweed is grown alongside other aquatic activities like fish farming or coral restoration, it can create a positive environment for those activities because the seaweed helps keep the water less acidic and more suitable for marine life.
The study sites in Okinawa, Japan are larger than any seaweed farms in the United States, and will help identify the risks and benefits of seaweed farming at scale. These larger operations will provide a realistic picture of what is required in terms of space and infrastructure to meet certain goals in terms of carbon capture or local mitigation of ocean acidification.
Researchers will use state-of-the-art ocean sensors to measure key variables such as water flow across the seaweed farms, which affects their productivity and the amount of carbon absorbed. Numerical modeling will elucidate the capacity of seaweed to absorb carbon under a range of different conditions. By comparing the estimates generated by the numerical modeling to the amount of seaweed harvested and exported each year, the team hopes to identify each farm’s capacity for carbon capture.
Other researchers working on the project include Satoshi Mitarai, Okinawa Institute of Science and Technology; Loretta Roberson, Marine Biological Laboratory (MBL); Reggie Spaulding, Sunburst Sensors; and Adrienne Sutton, NOAA Pacific Marine Environmental Laboratory.
Exploring Marine Carbon Removal
Carbon dioxide removal is not a replacement for reducing greenhouse gas emissions but it may still play a crucial role in limiting the negative effects of climate change. The size of this role will be determined in no small part by how cheap and how efficient the process can become.
Dickson’s project focuses on a new strategy that promises low energy usage and low manufacturing costs to capture carbon and then use salts created in the process to conduct ocean alkalinity enhancement.
Ocean alkalinization involves adding alkaline substances to seawater to kick off a series of chemical reactions that convert dissolved carbon dioxide in the ocean into stable bicarbonate and carbonate molecules, which in turn allow the ocean to absorb more carbon dioxide from the atmosphere to reach equilibrium.
The project will build and test a pilot-scale system for carbon dioxide removal from combustion gases exhausting from gas-powered furnaces and boilers, and then investigate how the alkaline chemicals produced can be used to enable marine carbon dioxide removal. The researchers will also evaluate the chemical and biological impacts of ocean alkalinity enhancement for different habitats along the U.S. West Coast, contributing to the knowledge and implementation of sustainable strategies for carbon dioxide removal.
“For marine carbon dioxide removal to be successful, it needs to happen soon, be environmentally safe, and to be economically viable,” said Dickson. “We hope to show all can be true together.”
Other researchers working on the project are Robert Richardson, Pacific Rim Design & Development; Nina Bednaršek, Cooperative Institute for Marine Resources Studies / Oregon State University; and Richard Feely, NOAA / Pacific Marine Environmental Laboratory.
About Scripps Oceanography
Scripps Institution of Oceanography at the University of California San Diego is one of the world’s most important centers for global earth science research and education. In its second century of discovery, Scripps scientists work to understand and protect the planet, and investigate our oceans, Earth, and atmosphere to find solutions to our greatest environmental challenges. Scripps offers unparalleled education and training for the next generation of scientific and environmental leaders through its undergraduate, master’s and doctoral programs. The institution also operates a fleet of four oceanographic research vessels, and is home to Birch Aquarium at Scripps, the public exploration center that welcomes 500,000 visitors each year.
About UC San Diego
At the University of California San Diego, we embrace a culture of exploration and experimentation. Established in 1960, UC San Diego has been shaped by exceptional scholars who aren’t afraid to look deeper, challenge expectations and redefine conventional wisdom. As one of the top 15 research universities in the world, we are driving innovation and change to advance society, propel economic growth and make our world a better place. Learn more at ucsd.edu.