Minneapolis is on track to become one of the first U.S. cities to invest in biochar, a multifunctional, charcoal-like material said to help grow bigger plants, reduce storm water runoff and remove carbon from the atmosphere. Minneapolis is on track to become one of the first U.S. cities to invest in biochar, a multifunctional, charcoal-like material said to help grow bigger plants, reduce storm water runoff and remove carbon from the atmosphere. Environment Phys.org – latest science and technology news stories