a green container ship travels full-steam through the ocean, its deck loaded with a multicolored array of shipping containers

New technology, developed by USC researchers and funded in part by the Wrigley Institute, mimics natural ocean processes to capture and reduce carbon dioxide emissions from shipping. (Photo: Adobe Stock)

New USC technology may halve emissions from global shipping

June 25, 2025

Original story by Nina Raffio

Scientists at USC and Caltech, in collaboration with startup company Calcarea, have developed a promising shipboard system that could remove up to half of carbon dioxide emitted from shipping vessels by converting it into an ocean-safe solution.

The breakthrough, described in Science Advances, shows how the system could reduce carbon emissions from the shipping industry — one of the world’s most difficult-to-decarbonize sectors.

“What’s beautiful about this is how simple it is,” said William Berelson, the Paxson H. Offield Professor in Coastal and Marine Systems at the USC Dornsife College of Letters, Arts and Sciences and co-corresponding author of the study. “We’re speeding up a process the ocean already uses to buffer CO2 — but doing it on a ship, and in a way that can meaningfully reduce emissions at scale.”

The process mimics a natural chemical reaction in the ocean. As ships move through seawater, CO2 from their exhaust is absorbed into water pumped onboard, making it slightly more acidic. That water is then passed through a bed of limestone, where the acid reacts with the rock to form bicarbonate — a safe, stable compound that exists naturally in seawater. The treated water, now stripped of CO2, is then discharged back into the ocean.

“What’s most exciting to me is that this started as a pure science question: How does the ocean buffer CO2?” Berelson added. “From there, we realized we might have a real-world solution that could help fight climate change.”

VIDEO: Ocean-inspired tech could speed up carbon capture from ships

The research is sponsored in part by multiple Faculty Innovation Awards from the Wrigley Institute for Environment and Sustainability’s Climate and Carbon Management Initiative.

Learn more about Wrigley Institute research >>