Leith Sharp studies and teaches leadership for sustainability in organizations and teams; she directs Executive Education for Sustainability Leadership at Harvard's Chan School of Public Health. We had a fascinating discussion with her about human engagement, the limits of formal power, and fostering change through stakeholder ecosystems. Leith led Harvard’s green campus transformation in the early 2000s and has deep insights about project and movement dynamics. Big picture, Leith reminds us that we are a young organism facing an evolutionary challenge and that we need to turn to biology as the frame for the systems and cultural changes ahead.