Melting polar ice due to climate change is making earth’s days longer

Sub: Geo

Sec: Climatology

Slower Earth Rotation Due to Melting Polar Ice Caps:

Scientists have found that the melting of polar ice caps is causing the Earth to spin slower, leading to slight changes in the duration of a day.
Although this change is minor and does not significantly affect daily life, it can have implications for technologies that rely on precise timekeeping, such as computer networks and space travel systems.

Conservation of Angular Momentum and Earth’s Rotation:

The phenomenon is explained by the conservation of angular momentum, where the Earth behaves similarly to an ice-skater. When ice sheets and glaciers melt, water moves towards the equatorial regions, increasing the Earth’s oblateness and moment of inertia, thus slowing its rotation rate.
This pole-to-equator mass flux causes the Earth to bulge at the equator, leading to a lengthening of the day as the rotation slows.

Impact of Climate Change on Earth’s Rotation:

Researchers used climate models and data spanning 200 years to show that over the past two decades, the slowing of Earth’s rotation due to climate change has reached around 1.3 milliseconds per century.
If high emission scenarios continue, this rate could increase to 2.6 milliseconds per century, making climate change the dominant factor in slowing Earth’s rotation.
These changes, though measured in milliseconds, can impact precise timekeeping with atomic clocks, necessitating adjustments such as the addition of leap seconds to maintain synchronization.

Lunar Tidal Friction and Other Influences:

Lunar tidal friction, or the moon’s gravitational pull on Earth’s oceans, has already been slowing Earth’s rotation by about 2 milliseconds per century.
Other processes, like the slowed rotation of Earth’s core and crustal rebound after the ice age, have been contributing to a faster rotation, prompting discussions on the potential need for a negative leap second.

Climate Change and Earth’s Axis Shift:

Studies have shown that melting ice is not only slowing Earth’s rotation but also affecting the Earth’s axis of rotation, causing a slight shift in the location where the axis intersects the crust.
For people in low-lying coastal areas, the rising sea levels from melting ice have more severe consequences, highlighting the urgency of addressing climate change and reducing emissions to prevent further disruption of planetary systems.

Source: TH