The twin key environmental challenges of our times are to stabilise our climate system and reverse the decline of biodiversity. Tropical forests play an important role in addressing both these challenges. Professor Yadvinder Malhi, Professor of Ecosystem Science at the University of Oxford, will explore what role tropical forests play in the Earth System and will discuss the interaction between tropical forests and climate change, highlighting some of his team’s recent research that combines detailed field data collection with satellite remote sensing. Field work and observations remain an essential component of understanding and stewarding our changing biosphere.