David is CEO at One Tribe. He has previously served as CEO at Trees for Cities, a leading environmental NGO transforming urban green spaces, and at the Future Forest Company, a start-up company delivering nature-based solutions. He has been a Commissioner for the London Sustainable Development Commission, which advises the Mayor of London and Greater London Authority on sustainability programmes across the capital. He is a Trustee for a range of environmental organisations, and a mentor and advisor for green and clean tech start-ups.