Climate-Induced Polar Motion: 1900–2100

Abstract

It has been demonstrated that the motion of the Earth's rotational pole with respect to the crust—termed polar motion—is increasingly influenced by barystatic processes, that is, continental-ocean mass redistribution due to melting of polar ice sheets, global glaciers, and variations in terrestrial water storage. However, how these processes might impact polar motion in the ${21}^{\text{st}}$ century is not known. Here we investigate this problem under various climatic scenarios, namely, Representative Concentration Pathways (RCP) and Shared Socioeconomic Pathways. We show that the climate-induced polar motion is sensitive to the choice of climatic scenario; under the optimistic RCP2.6, the rotational pole might wander by $\sim$12 m with respect to 1900, whereas under the pessimistic RCP8.5 by more than twice as much ($\sim$27 m). The most important contributor is the melting of polar ice sheets (Greenland and, to a lesser degree, Antarctica), followed by melting of global glaciers, and variations in terrestrial water storage.