# Earth's interior heat ratio between pressure and atomic decay

What is our current understanding between the ratio of Earth's interior heat between the downward pressure and atomic decay?

The total heat budget of the Earth is pretty well constrained: we can just measure the heat flow coming out at the surface (in W/m$$^2$$) and multiply this by the Earth's area. The current estimate is ~47 TW (Davies & Davies, 2010). Getting ratios between sources, however, is more difficult, and rely mostly on modelling. See for instance the work of Dye (2012), who proposed a radiogenic heating of 15–41 TW, while other authors (referenced by Dye) proposed 12–30 TW of primordial ("fossil") heat. As you can see, the uncertainty is still quite high...