The findings show that as polar ice sheets and glaciers melt as a consequence of climate change<\/a>, water that was once locked up at high latitudes flows into the oceans and spreads toward the equator.<\/p>\n This shifts mass away from Earth\u2019s poles, and \u2013 like a figure skater extending their arms mid-spin \u2013 slows the rotation.\u00a0<\/p>\n Previous studies<\/a> had already shown that climate change was having strange effects on our planet\u2019s spin. Now, the team from the University of Vienna and ETH Zurich have looked back through geological time to ask whether anything like today\u2019s rate of change has happened before.\u00a0<\/p>\n The answer, unequivocally, is no.\u00a0<\/p>\n Reading time in ancient shells<\/p>\n The length of a day has never been perfectly fixed. Earth\u2019s rotation is constantly being nudged by the gravitational pull of the Moon, by processes deep within the planet\u2019s interior and by shifts in the atmosphere.<\/p>\n These forces push and pull in different directions, and, over geological time, they\u2019ve produced swings in how long a day lasts. What scientists have now established is that climate change has become a force powerful enough to stand alongside, and, in time, dwarf all of them.<\/p>\n To look back millions of years, the researchers turned to the fossilised remains of a single-celled marine organism that lived on the sea floor, known as benthic foraminifera.\u00a0<\/p>\n The chemistry of their shells records ancient shifts in sea level. By looking at these shifts, the researchers can calculate how Earth\u2019s rotation must have changed.<\/p>\n A specially developed machine learning algorithm, designed to handle the uncertainties in data this old, allowed them to draw robust conclusions from material stretching back to the Late Pliocene, 3.6 million years ago.<\/p>\n Across that entire sweep of time, one data point stands out: today.\u00a0<\/p>\n The current rate of climate-driven day lengthening \u2013 1.33 milliseconds per century \u2013 sounds trivial. But considering the forces involved, the mass redistribution is gigantic.<\/p>\n \u201cSuch a shift in the length of day requires a staggering redistribution of mass: on the order of 1,000 gigatonnes moving from the poles to the oceans,\u201d says Prof Benedikt Soja<\/a> of ETH Zurich, co-author of the study. \u201cTo visualise this amount, imagine a solid cube of ice placed over New York City. It would be 10km high, taller than Mount Everest.\u201d<\/p>\n![\"Melting](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2026\/05\/ice-melting.jpg\")
As water once locked in ice melts, the planet bulges at the equator, forcing the speed of rotation to slow – Photo credit: Getty<\/p>\n
![\"The](\"https:\/\/www.newsbeep.com\/ca\/wp-content\/uploads\/2026\/05\/moon.jpg\")
Under a \u2018business-as-usual\u2019 scenario, with continued heavy reliance on fossil fuels and a global temperature rise of 3\u00b0C\u20135\u00b0C, climate change’s impact on Earth’s rotation will outstrip the gravitational effects of the Moon – Photo credit: Getty<\/p>\n