2026 Volume 36 Issue 3 Pages 178-185
Recent advances in high-pressure experiments and first-principles calculations have changed how we understand the thermal conductivity of iron and iron alloys under conditions similar to those in the Earth’s core. Contrary to the long-standing assumption of low thermal conductivity, these studies suggest substantially higher values at core pressures and temperatures. This paradigm shift has profound implications for the thermal evolution of the core, the onset and maintenance of the geodynamo, and the age of the Earth’s inner core. In this article, we will review the traditional low-conductivity framework and introduce the emerging high-conductivity model. We will also discuss the consequences of the model for inner-core formation, core stratification, and the long-term evolution of the Earth and other terrestrial planets.