How your morning coffee can help build greener cities

Do you start your day with a cup of coffee? The world's 10 billion kilograms of annual coffee waste usually rots in landfills, spewing greenhouse gases. But now, scientists are turning it into biochar to replace up to 15% of sand in concrete, boosting strength by 30% and cutting carbon footprints by up to 26%. Zhao Ying speaks with Dr. Zhang Jingxuan from the School of Engineering at RMIT, who leads the Life-Cycle Assessment of coffee waste for low-carbon concrete.