The third episode of House on Fire explores a new initiative to grow and conserve a trillion trees on Earth. Is large-scale tree planting even viable? What good would it do and where could it go wrong? To answer these questions we talk to foremost experts – from scientist Tom Crowther to ecologist Karen Holl, from environmentalist Forrest Fleischman to Justin Adams, co-director of the One Trillion Trees platform – to weight the pros and cons of the world’s new fascination for forestation.   See acast.com/privacy for privacy and opt-out information.