Something strange is happening to Earth's rotation. Now we know why

[Judi Lynn]

Earth is wobbling more than it should. Scientists say massive water losses are to blame

Tom Howarth
Published: April 20, 2025 at 5:00 am

Over the past two decades, Earth’s rotation has been behaving oddly – and scientists have finally pinned down one surprising reason: we’re losing water from the land.

A new study published in Science reveals a dramatic shift in the Earth’s axis since the early 2000s – amounting to a wobble of about 45 cm – was not caused by changes in the core, ice loss or glacial rebound, but by a massive and previously underappreciated loss of soil moisture across the planet.

In just three years, from 2000 to 2002, the world lost over 1,600 gigatonnes of water from its soils – more than the mass of Greenland’s ice loss over a much longer period.

And once that water drained into the oceans, it left a mark on the planet’s balance so distinct, it nudged Earth’s spin.

“There was a period of several years in the early 2000s where there seemed to be a big loss of water from the continents as predicted by a particular climate model,” Prof Clark Wilson, a geophysicist at the University of Texas at Austin and co-author of the study, tells BBC Science Focus.

More:
https://www.sciencefocus.com/news/earths-rotation-soil-moisture