The Earth has shifted relative to its spin axis over the past 12 million years (Ma). This shift, which geoscientists call true polar wander, caused the Earth's mantle beneath the tropical Pacific to move southward while causing Greenland to move northward. The latter motion may have contributed to the onset of the current ice age, which began ≈3 Ma before present. These conclusions follow our analysis of the history of motion of the Pacific tectonic plate relative to the spin axis, which is preserved in sediments and rocks on the Pacific seafloor. We also infer the motion of the Pacific plate relative to the solid Earth from the plate's history of motion relative to hot spots, such as Hawaii. Hot spots are sites of voluminous volcanism, thought to lie over rising plumes of hot rock from deep in the Earth's mantle. As the Pacific plate moves over the Hawaiian plume, it creates a line of extinct volcanoes that record the motion of the plate relative to the plume. Combining this information, we find that Hawaii and other global hot spots were nearly fixed in latitude from 48 to 12 Ma before present, which marks a 36‐Ma‐long time interval preceding the shift.