One of the consequences of rising CO2 levels in our atmosphere is that levels also rise proportionately in the ocean, harming wildlife and changing ecosystems. Heimdal is a startup working to pull that CO2 back out at scale using renewable energy and producing carbon-negative industrial materials, including limestone for making concrete, in the process, and it has attracted significant funding even at its very early stage.
If the concrete aspect seems like a bit of a non sequitur, consider two facts: concrete manufacturing is estimated to produce as much as eight percent all greenhouse gas emissions, and seawater is full …