This scene is all too familiar along North Carolina’s coast: houses and roads underwater, beaches washed away, lives and livelihoods threatened. Massive weather events often leave us feeling helpless, and even hopeless.
From harsh hurricanes to rising sea levels, North Carolinians have experienced firsthand the devastating impacts of climate change. Indeed, the recently published Intergovernmental Panel on Climate Change 2023 Report shows dire circumstances and catastrophic effects if drastic action is not taken now to mitigate the climate crisis. An all-of-the-above approach is required, including strategies to both reduce carbon emissions and remove carbon dioxide directly from the atmosphere.
What if there were a nature-based climate restoration solution that may eventually be able to safely capture 1 billion tons or more of carbon dioxide from the atmosphere each year while reducing harmful ocean acidity and helping to protect coastlines?
This is exactly the kind of promising carbon dioxide removal strategy that my lab at the University of North Carolina Wilmington is exploring in collaboration with scientists from Vesta, as well as the Coastal Studies Institute, UNC-Greensboro, and researchers at the U.S. Army Corps of Engineers (USACE).
Vesta is a Public Benefit Corporation conducting research into the efficiency and scalability of a climate restoration solution called Coastal Enhanced Weathering: a method that places carbon-removing sand made of the naturally occurring mineral, olivine, into seawater, reducing ocean acidity and removing carbon dioxide from the atmosphere. Olivine reacts with carbon dioxide in seawater to sequester it as bicarbonate, raising ocean alkalinity and releasing silicate, an important nutrient for near-shore phytoplankton. Olivine is one of the most abundant minerals worldwide with natural deposits occurring across the United States including in North Carolina.
Vesta is currently seeking permits for a 2024 field pilot project to place a small amount of olivine sand 1,500 feet offshore of Duck on the seafloor in 25 feet of water. This sand placement is about 2% of the volume of coastal beach nourishment projects such as the recent 500,000-cubic-yard Shore Protection Project conducted by the Town of Duck earlier this year. As part of the pilot project’s multi-year environmental monitoring program, we are planning to conduct measurements and experiments to study responses of nearshore phytoplankton and zooplankton to this real-world deployment of olivine sand.
I’ve studied important marine microbiota that support the base of ocean food webs both in the lab and in the field for decades. I have also studied their responses to coastal nourishment projects in North Carolina that similarly place sand in coastal zones to counteract erosion. We have found that “standard” beach nourishment projects have no long-term effects on nearshore phytoplankton and zooplankton at the base of the food web.
Moreover, we know that nearshore primary productivity is almost always nutrient-limited, including by the nutrient, silicate, which is necessary for the growth of diatoms, a very important food source for zooplankton and other herbivores in the surf zone. Given the small scale of the potential 2024 field pilot project, particularly relative to typical coastal nourishment projects in the area, and the extensive laboratory research to date, no impacts to marine plankton are expected. Nevertheless, it is critical to test this thinking through rigorous scientific study, as we plan to do.
Vesta teamed up with the Town of Southampton, New York in a pilot study in 2022 to contribute a small amount of olivine sand to the town’s beach renourishment effort, equaling 5% of the total nourishment volume to restore the eroding shoreline. After the first year, preliminary results showed no changes to in-field chlorophyll A concentrations (an indicator of phytoplankton abundance) following the placement of olivine. Additionally, in collaboration with researchers at the University of Southern California, Vesta recently released this preprint for peer review, in which they conducted a laboratory study showing no negative responses of numerous phytoplankton groups upon exposure to extremely high levels of olivine constituents.
This laboratory experiment created an extreme scenario of exposure to olivine dissolution products to represent a large olivine deployment and still observed no negative impacts. Other lab-based research supports the safety of Coastal Enhanced Weathering with olivine (Guo et al. 2022). Collectively, these data are very compelling as to the safety of this climate mitigation method.
The project in North Carolina would further the research and development of this important work in direct alignment with North Carolina’s Climate Goals. In coordination with the Coastal Studies Institute, UNC Greensboro, and scientific researchers at the U.S. Army Corps of Engineers (USACE) Field Research Facility, we will gain critical, real-world data that will advance the carbon removal industry and in turn, our ability to mitigate against climate change and the worst of its impacts.
The work has big promise. Together, we can find a solution and craft a better future for North Carolinians for generations to come.
To stimulate discussion and debate, Coastal Review welcomes differing viewpoints on topical coastal issues. See our guidelines for submitting guest columns. Opinions expressed by the authors are not necessarily those of Coastal Review or our publisher, the North Carolina Coastal Federation.