Climate change and the collapse of biodiversity, caused by human activity, are already resulting in a major ecosystem crisis. Accused of immobilism, catastrophism, or of having played into the hands of lobbies for too long, the media have a crucial role to play in bearing witness to this crisis and in highlighting mitigation and adaptation solutions. These questions are explored in depth in the tenth issue of our biannual publication, "Mediation", which you can leaf through or download above, with interviews and testimonies from journalists and researchers, as well as figures and maps to provide food for thought and pointers for action.