FIDUCEO is a Horizon 2020 Project that created insights from metrology (measurement science) to the observation of Earth’s climate from space. The project tried and tested a novel approach through the creation of new versions of four key Fundamental Climate Data Records (FCDRs), which include state-of-the-art information about observational uncertainty.  These FCDRs were derived from a cross-section of sensors, spanning the visible, infrared and microwave. The propagation of this information to derived geophysical datasets was demonstrated through the creation of five important climate data records (CDRs) developed with traceable uncertainty and stability estimates.