Climeworks execs had heard all the arguments: Carbon capture and storage technology can’t do much to stop climate change unless it’s deployed on a massive scale. So the Swiss company went big—building the world’s largest carbon capture plant just outside Reykjavik. To keep the schedule lean, the team behind Orca—which means energy in Icelandic—relied on modular design. And to deliver maximum sustainability, project leaders specifically chose a site close to local utility ON Power’s geothermal plant, allowing the facility to run exclusively on renewable energy. That was just the start. Climeworks recently broke ground on another project, cheekily named Mammoth. And this one is being built with nine times the carbon capture capacity of Orca—gobbling up roughly 36,000 metric tons per year. For Climeworks co-founder Christoph Gebald, carbon capture projects reflect the need for options—providing the world with one more weapon in the fight against climate change. “To achieve climate targ...