USC researchers in the waters off Huntington Beach. The group, all from Will Berelson’s USC lab, are studying whether the ocean floor can help absorb excess carbon dioxide from the atmosphere. (Photo: Stephen Gee/USC)
Is a solution to excess CO2 hiding in the ocean floor?
Original story by Nina Raffio
The ocean plays a vital role in protecting the planet, absorbing about 31% of the carbon dioxide (CO2) released by human activity, storing it in its waters and neutralizing some of it by reacting with sediments. This natural process has helped keep Earth’s climate in balance for millennia, but it moves slowly, unfolding over thousands of years.
Today, with carbon emissions rising far faster than the ocean can absorb them, scientists are looking for ways to better understand — and potentially enhance — the ocean’s natural ability to capture and store carbon.
Just beyond the surf at Huntington Beach, a team of USC oceanographers is investigating the potential role of the sandy ocean floor in this process.
“The seafloor is actively involved in carbon cycling,” said lead researcher Will Berelson, a Wrigley Institute faculty affiliate and the Paxson H. Offield Professor in Coastal and Marine Systems.
“In this shallow area just offshore, where waves and currents are constantly stirring up the sandy bottom, we’re seeing chemical reactions take place in the tiny pockets of water between grains of sand,” he said. “Those reactions might help the ocean store more carbon, and we’re trying to find out how prevalent and effective is this natural process.”
Berelson’s team is using a custom-built device to sample porewater, the water held in the spaces between grains of sand on the ocean floor. The device can draw up samples without disturbing the seafloor. The researchers then take the samples back to Berelson’s lab to look for chemical signatures that indicate where the CO2 in the water originated.
Along with experiments focused on seawater’s capacity to absorb atmospheric CO2, this process can help the researchers determine whether the ocean floor can contribute meaningfully to efforts to remove excess CO2 from Earth’s atmosphere. The collected data can also inform new methods for increasing the ocean’s carbon-storage capacity.
Mohammed Hashim, a Wrigley Institute Ballmer postdoctoral researcher stationed in Berelson’s lab, assisted on the group’s recent sampling trip. His work is testing methods for increasing the ocean’s alkalinity, a change that could boost carbon storage and help counteract rising acidity caused by ocean warming.
This research is supported in part by USC Sea Grant, part of the USC Wrigley Institute for Environment and Sustainability.
Read the full story on USC News >>
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