The melting of polar ice caps due to global warming is causing the Earth’s rotation to slow down, posing challenges for adjusting standard time. Currently, we rely on about 450 atomic clocks to maintain Coordinated Universal Time (UTC), which was introduced in 1969 to track time more accurately than relying on the Earth’s rotation. To account for fluctuations in the Earth’s rotation, scientists have added 27 leap seconds to standard time since 1972.
Recent research by geologist Duncan Agnew at the University of California suggests that this change in angular velocity is caused by melting ice in Greenland and Antarctica. While this change is imperceptible to humans, it can impact computers that rely on precise timekeeping. This reduction in the Earth’s angular velocity may necessitate a reduction in leap seconds by 2026, but Agnew’s team now believes this adjustment may not be needed until 2029.
Changes in the Earth’s rotation have always fluctuated due to geophysical processes like interactions between the core, mantle, and outer crust. However, with human activity causing a shift in mass distribution through melting ice caps, these fluctuations are affecting modern technology and systems that rely on UTC.
Agnew and his team use gravity data from satellites to track the decrease in Earth’s angular momentum and adjust timekeeping accordingly. By doing so, they are able to ensure that UTC remains accurate and consistent for various applications in our modern world. Despite ongoing evaluations regarding reducing leap seconds, it is clear that human activity is affecting the Earth’s rotation and timekeeping systems. As such, scientists must carefully make necessary adjustments to ensure UTC remains reliable for all uses.
