Big money — from the three biggest economies in the world, as well as scores of ambitious venture capitalists — is suddenly flying toward startups promising to help the world build a carbon-free future. It’s a shift from the world of software into the actual world, following the trajectory of a tech founder like Peter Reinhardt, who sold a software company for $3.2 billion in 2020 and now leads carbon-storage company Charm Industrial. The newer startup, which he co-founded in 2018, turns carbon-rich biomass into sludge that can be safely buried underground.