Drift in globally-integrated ocean heat content (OHC; dH/dt) and its temperature (dHT/dt; Equation \ref{eq:ohc_thermal}) and barystatic (dHm/dt; Equation \ref{eq:ohc_mass}) components. Values represent the linear trend over the entire length of the pre-industrial control experiment for CMIP5 (to the left of vertical dividing line) and CMIP6 (to the right). For comparison, the current planetary energy imbalance is shaded (estimates range from 0.4-1.0 Wm-2).