Can We Make Oceans Absorb More Carbon Dioxide with a Giant Antacid?

If we dissolve acid-neutralizing rocks in the ocean, will it absorb more carbon dioxide?

Climate ventures and philanthropic funders have been spending millions of dollars to find out, reports the Washington Post. 'Researchers have been exploring this technology for the last five years, but over the last two months, at least a couple of start-ups have begun operation along the Atlantic and Pacific coasts.'

Planetary, a start-up based in Nova Scotia, removed 138 metric tons of carbon last month for Shopify and Stripe. The start-up Ebb Carbon is running a small site in Washington that can remove up to 100 carbon metric tons per year and committed in October to remove 350,000 metric tons of carbon from the atmosphere over the next decade for Microsoft.

Proponents of the technology say it's one of the most promising forms of carbon removal, which experts say will be necessary to meet climate goals even as the world cuts emissions. But in order for this to make a dent, it will need to be scaled up to remove billions, not hundreds of thousands, of metric tons of carbon per year, Yale associate professor of earth and planetary sciences Matthew Eisaman said... Removing carbon could also help prevent ocean acidification. Although the ocean's chemistry has varied through geologic time, it has become more acidic as it has absorbed more carbon from human-generated emissions, said Andy Jacobson, a geochemist at Northwestern University. The increased acidity makes it difficult for some marine organisms to build their skeletons and shells...

Researchers are still investigating the best strategy to implement the method. Ebb Carbon, for example, takes existing saltwater waste streams from treatment and desalination plants and uses electricity to alkalize it before returning it to the ocean, said Eisaman, who is the start-up's co-founder and chief scientist. Another method is depositing alkaline minerals or solution into the ocean using a ship; others want to enhance the rock weathering that already occurs on the coast...

The growing evidence from early studies in labs and controlled outdoor settings suggest no serious impacts on plankton, which are at the bottom of the food web.

Read more of this story at Slashdot.