City dwellers often refer to life in the "concrete jungle," but most probably aren't aware of the fact that cement accounts for 8% of global emissions. Innovative efforts are underway to decarbonize the industry, so that the infrastructure and architecture we rely on can help to provide a greener future. In partnership with a US public broadcaster, we zero in on some of the researchers who are pushing the boundaries by turning alternative materials into actual building blocks. Host: Catherine Kobayashi Guest: Greg Dalton, Journalist and Host, "Climate One"