The Earth is spinning faster than it has in five years, with Tuesday, Aug. 5, predicted to be just over a second shorter than a full day. This trend is caused by the moon and seasonal changes in the atmosphere, which make the planet spin slower at certain times but speed up overall. The recent acceleration of Earth’s rotation has scientists concerned about the possibility of a negative leap second, a jump from UTC time.
Since 1972, 27 leap seconds have been added to the Coordinated Universal Time (UTC) system to account for Earth’s slowing down due to its rotational momentum. However, with the planet speeding up, experts now question whether another leap second will be needed in the near future.
According to Duncan Agnew, a professor emeritus of geophysics, scientists track changes in Earth’s rotation using atomic clocks and satellites that monitor the position of the planet relative to fixed stars. These fluctuations can be predicted with short-term accuracy but become uncertain over longer intervals.
The role of climate change is also being explored as a factor contributing to the faster spin rate of Earth. Melting ice sheets from Antarctica and Greenland are slowing down the planet’s rotation by spreading mass over oceans, much like a skater spinning slower when their arms are tucked in.
While some experts believe the trend may be short-lived, with the possibility of the planet slowing down again in the future, others warn that the impact of climate change could become dominant. The prospect of a negative leap second raises concerns about the potential for widespread disruptions to modern technological systems, such as telecommunications and GPS satellites, which rely on precise timekeeping.
As the world continues to monitor Earth’s rotation speed, scientists emphasize the importance of ongoing research and preparation for any potential changes in timekeeping standards.
Source: https://www.wral.com/lifestyle/shortest-day-aug-5-2025-earth-spin