In the second episode of a four-part special series on leadership, HBR Editor in Chief Adi Ignatius and Harvard Business School professor and historian Nancy Koehn trace the modern environmental movement back to Carson’s pioneering reporting and powerful prose. ADI IGNATIUS: I’m Adi Ignatius, Editor in Chief of Harvard Business Review and I’m here with Nancy Koehn, a great historian at Harvard Business School who has researched Carson’s exceptional life. ADI IGNATIUS: Next time on “Real Leaders,” Nancy Koehn and I will be talking about Abraham Lincoln.