One of the repercussions of rising CO2 concentrations in the atmosphere is that levels have risen correspondingly in the ocean, causing creatures to suffer and ecosystems to change. Heimdal is a firm that is aiming to suck CO2 out of the atmosphere at scale using renewable energy while also generating carbon-negative industrial materials, such as limestone for concrete, in the process, and it has already received significant funding.

Consider two facts if the concrete aspect appears to be a little of a non sequitur: Concrete production is projected to account for up to 8% of global greenhouse gas emissions, and the minerals necessary to manufacture it are abundant in saltwater. You wouldn’t make this link unless you were operating in a comparable sector or discipline, but Heimdal co-founders Marcus Lima and Erik Millar did while pursuing their master’s degrees at Oxford. He added, “We came out and performed this right away.”

They both believe that climate change poses an existential danger to mankind, but are frustrated by the lack of long-term answers to the many and varied impacts it has around the world. Carbon capture is often a circular process, according to Millar, in which carbon is captured just to be utilized and emitted again. Sure, it’s better than creating new carbon, but why aren’t there more methods to permanently remove carbon from the ecosystem?

The two founders imagined a new linear procedure that uses only power and CO2-rich saltwater to create usable materials that permanently store CO2. Of course, if it were that simple, everyone would be doing it.

“The carbon markets that will make this commercially feasible have only recently emerged,” Millar said. And, as a result of massive solar and wind projects, energy costs have fallen, overturning decades-old power economies. With the carbon credits and cheap energy come new enterprise models, and Heimdal’s is among them.

The Heimdal process, which has been proven in the lab (imagine terrariums rather than thousand-gallon tanks), goes like this: The saltwater is first alkalinized, which raises the pH and allows the separation of the gaseous hydrogen, chlorine, as well as a hydroxide sorbent. This is combined with a separate stream of seawater, resulting in the precipitation of the calcium, magnesium, as well as sodium minerals as well as a reduction in CO2 saturation in the water, allowing it to absorb more CO2 from the atmosphere when returned to the sea.