Solar Irradiance is the key energy input to Earth. A positive Earth Energy Imbalance (EEI) is the energy, which is continuously stored by the Earth and will ultimately be released to the atmosphere, causing global warming. In order to determine its exact value both the Total Solar Irradiance (TSI) and the Top of the Atmosphere (ToA) Outgoing Radiation (TOR) need to be measured with unprecedented accuracy and precision. However, so far, the EEI could not be determined as the measurements were not sufficiently accurate. This calls for improved instrument technologies as well as a traceable calibration chain of the space instrumentation. In this session we invite contributions on the both the measurement of solar irradiance as well as the Earth outgoing radiation which ultimately aim to pave the way to determine EEI from space.