Scientists are turning to the living world to find alternatives for concrete. Many different animals, such as tortoises, turtles and oysters, produce hardened structural materials of their own — but one of the most interesting sources of hard materials comes from certain bacteria that produce calcite, a form of calcium carbonate that makes up limestone.
Concrete is the most widely consumed material on Earth, with about 25 billion tons produced every year. It lasts decades longer than other building materials and it doesn’t burn, rust or rot. But the manufacturing of cement, the primary component of concrete, is the most energy intensive of all manufacturing industries; it’s a major source of carbon dioxide emissions, amounting to 2.8 billion tons per year or roughly 8 percent of global carbon dioxide emissions.
