The lithosphere, the outermost shell of the Earth, constitutes the upper thermal boundary layer of mantle convection. It is well established that its properties play a central role in the development of solid Earth dynamics. Through its properties the lithosphere also provides a primary source of thermal and chemical anomalies for mantle convection when it is injected in the mantle as subducting slabs. Here, the subduction of cold and dense oceanic lithosphere into the underlying mantle acts as the major driving force of plate motion, and as a key component of the water and carbon cycles throughout the Earth. At the global scale, some of these lithosphere heterogeneities include rheological stratifications, sutures, fracture zones, and lateral and vertical variations in temperature and composition. These exist at various scales and play a major role in determining subduction dynamics and the degree of lithosphere-mantle decoupling. Deciphering the interaction of the lithosphere with the underlying asthenosphere and deeper mantle is critical to understanding the secular evolution of the Earth system and to reconcile models with natural observations. This session aims to highlight recent advances in constraining the scales and amplitudes of heterogeneities in the lithosphere as well as their dynamic role. We welcome multidisciplinary contributions. Some key areas of interest are lithospheric structure and morphology, subduction kinematics and dynamics, slab-mantle interaction and slab deformation, active margin tectonics and subduction-induced seismicity.