Title: Whole planet coupling between climate, mantle, and core: Implications for the evolution of rocky planets,
Abstract: Earth's climate, mantle, and core interact over geologic timescales. Climate
influences whether plate tectonics can take place on a planet, with cool
climates being favorable for plate tectonics because they enhance stresses in
the lithosphere, suppress plate boundary annealing, and promote hydration and
weakening of the lithosphere. Plate tectonics plays a vital role in the
long-term carbon cycle, which helps to maintain a temperate climate. Plate
tectonics provides long-term cooling of the core, which is vital for generating
a magnetic field, and the magnetic field is capable of shielding atmospheric
volatiles from the solar wind. Coupling between climate, mantle, and core can
potentially explain the divergent evolution of Earth and Venus. As Venus lies
too close to the sun for liquid water to exist, there is no long-term carbon
cycle and thus an extremely hot climate. Therefore plate tectonics cannot
operate and a long-lived core dynamo cannot be sustained due to insufficient
core cooling. On planets within the habitable zone where liquid water is
possible, a wide range of evolutionary scenarios can take place depending on
initial atmospheric composition, bulk volatile content, or the timing of when
plate tectonics initiates, among other factors. Many of these evolutionary
trajectories would render the planet uninhabitable. However, there is still
significant uncertainty over the nature of the coupling between climate,
mantle, and core. Future work is needed to constrain potential evolutionary
scenarios and the likelihood of an Earth-like evolution.