The question of the heat budget of the Earth remains poorly understood. In particular, the contribution of the core to the budget remains wide open. This talk is about checks and balances - what are the sources of heat in the earth, where does the heat go, and how do we estimate the fluxes.

In particular we'll look at the tricky issue of estimating the contribution of the core to the global budget, and what the implications of the core's budget are for Earth history. The constraint of generating a magnetic field through most of Earth history is particularly challenging.