Polar motion, a small variation of the Earth’s rotational axis, is primarily caused by the Chandler wobble. The Chandler wobble has a period of roughly 14 months and is mainly caused by the unequal mass distribution of the planet. Although it is known to vary over time owing to a number of influencing factors, the degree to which changes in the ice mass, in particular the melting of ice sheets in Greenland and Antarctica and of glaciers in many polar and mountain regions, due to climate change can affect it is not well understood.

CanCan Xu and ChengLi Huang from the Shanghai Astronomical Observatory and the University of Chinese Academy of Sciences in Beijing and colleagues also from China used satellite gravity observations to assess the influence a changing ice mass on Earth has on the Chandler wobble. They find that variations in the ice mass are statistically linked with changes in the Chandler wobble. This relationship has strengthened in recent years, so that ice-mass variations contributed about 20% to the Chandler wobble in 2022, which is a four-times-stronger contribution compared with in 2006. The authors argue this indicates that the faster melting of ice due to global warming can also be expected to increasingly influence the Chandler wobble.