This chapter first describes the physical processes that govern the evolution of the polar ice sheets. Then the section briefly assesses whether the future evolution of the ice sheets would enable or constrain reaching the Paris Agreement temperature goals, followed by an assessment of how failing to reach the Paris Agreement goals would influence the future evolution of the ice sheets. The section ends with connecting the evolution of the ice sheets to other physical and social processes and assessing the plausibility of drastic change being triggered within the 21st century.
