CALIFORNIA RESEARCHERS ATTEMPT OCEAN CLIMATE SOLUTION

Atop a 100-foot barge tied up at the Port of Los Angeles, engineers have built a kind of floating laboratory to answer a simple question: Is there a way to cleanse seawater of carbon dioxide and then return it to the ocean so it can suck more of the greenhouse gas out of the atmosphere to slow global warming?

Called the lungs of the planet, the ocean, whose plants and currents take in carbon dioxide, has already helped the Earth tremendously by absorbing 30 percent of carbon dioxide emissions since the Industrial Revolution and capturing 90 percent of the excess heat from those emissions. Acting as a giant carbon sink, it has been a crucial buffer in protecting people from even worse effects of early climate change.

Seawater can store 150 times more carbon dioxide per unit volume than air, roughly. But absorbing the greenhouse gas has come at a cost, causing oceans to become more acidic, destroying coral reefs and harming marine species, including impeding shellfish from building their skeletons.

The technology, dubbed SeaChange, developed by the University of California Los Angeles engineering faculty, is meant to seize on the ocean’s natural abilities, said Gaurav Sant, director of UCLA’s Institute of Carbon Management.

The process sends an electrical charge through seawater flowing through tanks on the barge. That then sets off a series of chemical reactions that trap the greenhouse gas into a solid mineral that includes calcium carbonate — the same thing seashells are made of. The seawater is then returned to the ocean and can pull more carbon dioxide out of the air.

Plans are now underway to scale up the idea with another demonstration site starting this month in Singapore. Data collected there and at the Port of Los Angeles will help in the design of larger test plants. Those facilities are expected to be running by 2025 and be able to remove thousands of tons of CO2 per year. If they are successful, the plan is to build commercial facilities to remove millions of tons of carbon annually, Sant said.