|Carbon-Negative Concrete. Novacem photo|
Editor's Note: This is part of an excerpted series of a Yale Environment 360 interview by Richard Schiffman, with Tim Flannery, an Australian scientist and author. He discusses how “third way technologies,” that mimic the earth’s natural carbon-removing processes could provide a critical tool for slowing climate change.
e360: Turning to the chemical third way technologies, you write about carbon-negative concrete. What is that?
Flannery: It is a kind of concrete that uses different components for the cement from conventional concrete. It doesn’t emit C02 during the manufacturing process. As the concrete sets and matures, it actually absorbs C02 into its structure. So it is carbon-negative and its manufacturers claim that it is lighter, stronger and more durable than concretes made with Portland cement. But because it is a new product, it doesn’t have a track record. No one is going to build the Brooklyn Bridge from it just yet, because we aren’t sure how it is going to stand up. But there are a lot of low-risk uses for concrete that we can begin with as we try to grow that industry. And it is incredibly important because concrete manufacture accounts for about 5 percent of global emissions.