Ocean as ally? Start-ups explore CO2 storage in deep blue
In an effort to mitigate climate change, over a dozen start-ups are investigating methods to enhance the ocean's natural carbon dioxide (CO2) absorption capacity, reports The Wall Street Journal. Currently, oceans account for approximately 25-30% of all carbon absorption. "The ocean basically does the work for us," stated Tom Green, CEO of seawater carbon removal firm Vesta. These companies aim not to increase the load on already stressed oceans, but rather remove carbon from seawater using an electrochemical technique.
Innovative techniques to store carbon and protect oceans
These start-ups aim to safely store more greenhouse gases in the ocean, potentially allowing for the storage of up to one million metric tons of carbon. This is four times as much as what the whole carbon removal industry has achieved so far. Vesta, for example, plans to dissolve sand mixed with a mineral called olivine in seawater. The removed carbon is then either buried or converted into a solid material for construction purposes.
A radical plan to trap CO2 underwater
Another proposal involves injecting CO2 into basalt rock deposits at the ocean floor. Scientists suggest constructing floating rigs powered by wind turbines to extract CO2 from the atmosphere/seawater, and inject it into seabed holes. The project, known as Solid Carbon, aims to trap CO2 as rock at the bottom of the ocean. "That makes carbon storage very durable and very safe," said Martin Scherwath, a geophysicist working on Solid Carbon. However, scaling up this strategy would be slow and costly.
Basalt rock is a potential solution for carbon storage
The Solid Carbon project is based on a natural chemical reaction where basalt rock combines with CO2 to form carbonate minerals. Scientists estimate that basalt rock can store more carbon than all of Earth's fossil fuels can emit. A similar small-scale process has been successfully tested in Iceland by a project called CarbFix. However, funding remains a significant hurdle for Solid Carbon, which requires about $60 million to test a prototype at sea.
Ocean-based carbon capture: A complementary solution
Despite these innovative carbon capture techniques, experts stress that they are not replacements for immediate measures like transitioning from fossil fuels to renewable energy, and reducing carbon emissions from food systems. These techniques are seen as later choices to shave off the last few tenths of a degree of global warming. "You're gonna need every last drop," claimed David Goldberg, a geophysicist and professor of climate science and carbon management at Columbia University.
