What if we could use biology to restore our balance with nature without giving up modern creature comforts? Advocating for a new kind of environmentalism, scientist and entrepreneur Emily Leproust rethinks modern sustainability at the molecular level, using synthetic biology to create green alternatives. From lab-developed insulin and disease-resistant bananas to airplanes made of super-strong spider silk, she explains how reading and writing DNA can lead to groundbreaking innovations in health, food and materials.