Concrete is the world’s most manufactured product, and its environmental impact is similarly impressive — in particular, the large amount of carbon dioxide emitted during its production. Today, there are many scientists working to reduce that impact. Canadian researcher Leah Ellis co-founded a company that produces cement, which is one of the most energy-intensive parts of concrete, with electricity instead of burning fossil fuels. University of California Davis professor Somayeh Nassiri is studying ways to mix other materials with cement while reducing its carbon footprint – such as wood ash, volcanic ash, and ground-up crustacean shells. In Canada, University of British Columbia researcher Shahria Alam is looking at a circular approach to construction by making concrete with… more concrete, recycled from demolished structures.