New research reveals an unexpected consequence of human engineering: the massive dams built over the past two centuries have shifted Earth’s poles by more than a meter.
Scientists studying the planet’s rotational dynamics found that the redistribution of water caused by large reservoirs has altered Earth’s mass balance. When water is stored behind dams, it moves from the oceans to land, subtly changing how the planet spins. This shift, though small, is measurable—enough to nudge the poles roughly 34 millimeters per year in the direction of the reservoirs.
While natural processes like melting glaciers also influence polar drift, human-made water storage has had a surprisingly significant impact. The findings highlight how large-scale infrastructure projects can subtly reshape Earth’s physical properties in ways we’re only beginning to understand.