Anthropogenic climate change has given rise to a radiative flux imbalance at the top-of-atmosphere (TOA), referred to as Earth’s energy imbalance (EEI). Presently, the most reliable approach to estimate EEI is through assessing the rate of change of heat content across all Earth system components: ocean, cryosphere, land and atmosphere. The evolution of both EEI and associated internal energy exchanges will shape our future climate. To further our understanding of climate variability and change we encourage contributions from all relevant disciplines, exploiting in-situ measurements, reanalysis, climate modeling, and remote sensing techniques. Of particular interest are: discussions of uncertainty in heat storage estimates; characterization of the spatio-temporal variability of EEI and internal energy exchanges; processes perturbing energy budgets and energy flows through the climate system. Implications for key climate metrics, such as sea level, the hydrological cycle and climate extremes, as well as novel techniques that estimate EEI are also encouraged.