Q1. What is responsible for the cycle of day and night?

Earth’s Rotation is Slowed due to Climate Change which is Affecting Time

Utkarsh Classes Last Updated 03-04-2024

Earth’s Rotation is Slowed due to Climate Change which is Affecting Time

Report 5 min read

According to an analysis published in Nature, the melting ice caps are causing the Earth's rotation to slow down. This change in rotation speed is predicted to delay the next leap second by three years.

Since 1972, leap seconds have been used to reconcile the official time from atomic clocks with the Earth's unstable speed of rotation.

The leap second’s time's up

Scientists have recently predicted that global warming will delay the implementation of another leap second, from 2026 to 2029.
Leap seconds can cause significant disruptions in computing systems, which is why researchers have voted to eliminate them by 2035.
The next leap second, which is expected to be a negative or skipped second instead of an added one, is causing concern among scientists.

Synchronizing clocks

People have been measuring time using Earth's rotation for millennia, with a second being defined as a fraction of the time it takes for the planet to turn once on its axis.
However, atomic clocks that tick using the frequency of light emitted by atoms have served as more precise timekeepers since 1967. Around 450 atomic clocks define official time on Earth which is known as Coordinated Universal Time (UTC).
Leap seconds are used every few years to keep UTC in line with the planet's natural day.
Atomic clocks are considered as better timekeepers than Earth's because it stable over millions of years, while the planet's rotation rate varies
Many meteorologists expected that leap seconds would only ever be added because, on the scale of millions of years, Earth's spin is slowing down. This means that occasionally, a minute in UTC needs to be 61 seconds long to allow Earth to catch up.
The reduction in the planet's rotation rate is caused by the Moon's pull on the oceans, which creates friction.

Melting of ice

The Earth's rotation rate fluctuates due to geophysical phenomena on shorter timescales. The outer crust's rotation speed has been increasing since the 1970s because of currents in the planet's liquid core.
The Earth is becoming less spherical and more flattened, as revealed by satellite data mapping Earth's gravity.
This is because ice from Greenland and Antarctica has melted and moved mass away from the poles towards the Equator.
This flow of water slows down the planet's spin away from its axis of rotation, similar to how a spinning ice skater slows down by extending their arms away from their body.
Because of these changes, added leap seconds are needed less frequently, and if the trend continues, a leap second will need to be removed from UTC.

Precision problems

Meteorologists would appreciate a delayed leap second. Leap seconds are already a significant issue due to our society's reliance on precise timing. They cause major malfunctions in computing systems.

Earth Rotation responsible for time

The Earth's rotation causes the cycle of day and night, which in turn affects temperature and humidity. As the Earth rotates, the sea level rises and falls twice a day, creating tides. The gravitational pull of the sun and moon determines the tidal range.