It's well known that as far as the climate crisis goes, time is of the essence.

Now a study out Monday shows that the melting of the polar ice caps is causing our planet to spin more slowly, increasing the length of days at an "unprecedented" rate.

The paper, published in Proceedings of the National Academy of Sciences, shows that water flowing from Greenland and Antarctica is resulting in more mass around the equator, co-author Surendra Adhikari of Nasa's Jet Propulsion Laboratory told AFP.

"It's like when a figure skater does a pirouette, first holding her arms close to her body and then stretching them out," added co-author Benedikt Soja of ETH Zurich.

"The initially fast rotation becomes slower because the masses move away from the axis of rotation, increasing physical inertia."

Earth is commonly thought of as a sphere, but it's more accurate to call it an "oblate spheroid" that bulges somewhat around the equator, a bit like a satsuma.