The ESA Climate Change Initiative also produces satellite observations tracking carbon stocks on land and sea. Forests are the largest store of carbon on land. Fire acts as a conduit for carbon to pass from land to the atmosphere. Phytoplankton in the ocean are an important carbon sink. ESA’s RECCAP-2 project, which involves the University of Exeter, is combining Earth Observation data with atmospheric and biophysical computer models, calculating carbon fluxes at the surface. This helps to improve the precision of each greenhouse gas budget and distinguish separate natural fluxes from agricultural and fossil fuel emissions. This work will help us gauge whether we can stay within the 1.5°C carbon budget, or if more warming is in store.