This startup is geoengineering the oceans with Tums—with backing from Google, Shopify, and Stripe

For most of his career, Mike Kelland worked on software. But after selling his last startup in 2016, he decided to focus on climate change instead.

He zeroed in on one key part of the problem: Cutting emissions is no longer enough to address climate change on its own. He’d read an Intergovernmental Panel on Climate Change (IPCC) report that explained that we’ll also need to remove hundreds of billions of tons of CO2 from the atmosphere. “We’re 30 years beyond the point where decarbonization alone was enough,” Kelland says.

He spent nearly a year meeting with scientists to learn about potential new carbon removal technology, and eventually met a researcher working on ocean alkalinity enhancement—the process of adding alkaline minerals to the ocean to help it store more CO2. The method can also help reduce ocean acidification. But the tech was stuck in the lab.

“I said, this is the moment to take this and turn it into something,” Kelland says. In 2019, he cofounded Planetary, a startup focused on commercializing the idea. Now, at a site in Nova Scotia, the company is actively adding its “antacid” to the ocean.