The magma ocean that existed on the early Earth finally solidified to form a coherent lithosphere. This lithosphere insulated the underlying mantle leading to warming, thermal expansion, partial melting and a geoid bulge. This in turn may trigger breakup of the lithosphere and the onset of plate tectonics. As a consequence, heat balance is disturbed, which results in thermal fluctuation. On a global scale, a cycle of warming and cooling happened many times throughout geological history. This in turn may induce geological events as a response to the thermal cycles. The speaker will present a simple model of Earth evolution as a thermal system, based on rock fracture modeling method, trying to answer many questions about Earth鈥檚 history that are as yet unanswered.