E-Mail IMAGE: Melting of glaciers in Alaska, Greenland, the Southern Andes, Antarctica, the Caucasus and the Middle East accelerated in the mid-90s, becoming the main driver pushing Earth's poles into a sudden... view more Credit: Credit: Deng et al (2021) Geophysical Research Letters/AGU WASHINGTON-- Glacial melting due to global warming is likely the cause of a shift in the movement of the poles that occurred in the 1990s. The locations of the North and South poles aren't static, unchanging spots on our planet. The axis Earth spins around--or more specifically the surface that invisible line emerges from--is always moving due to processes scientists don't completely understand. The way water is distributed on Earth's surface is one factor that drives the drift.