The climate crisis is causing the length of each day to get longer, analysis shows, as the mass melting of polar ice reshapes the planet.

The phenomenon is a striking demonstration of how humanity’s actions are transforming the Earth, scientists said, rivalling natural processes that have existed for billions of years.

The change in the length of the day is on the scale of milliseconds but this is enough to potentially disrupt internet traffic, financial transactions and GPS navigation, all of which rely on precise timekeeping.

The length of the Earth’s day has been steadily increasing over geological time due to the gravitational drag of the moon on the planet’s oceans and land. However, the melting of the Greenland and Antarctic ice sheets due to human-caused global heating has been redistributing water stored at high latitudes into the world’s oceans, leading to more water in the seas nearer the equator. This makes the Earth more oblate – or fatter – slowing the rotation of the planet and lengthening the day still further.