 And I'm Guy Raz. Later on How I Built This, I talked to Cody Finke, an entrepreneur with a chemistry background, about how his company Brimstone uses an entirely new process of making cement because the current process is a carbon emissions nightmare. The majority of the CO2 emissions from cement come from that chemistry. We're releasing the CO2 from the rock. Wow. It's just another way that humans are perturbing the global carbon cycle. It's an hour of economics and innovation on How I Built This. And Planet Money from NPR.