With more than 100 global leaders at COP26 having pledged to halt and reverse deforestation and land degradation by the end of the decade to help address the climate crisis, the health of the world’s forests is high on the political agenda. ESA’s Biomass mission will soon play a key role in delivering novel information about the of the state of our forests, how they are changing over time, and advance our knowledge of the carbon cycle. With launch scheduled for 2023, the mission is now in its last phases of development, having recently passed several key milestones.