As global warming accelerates the melting of Earth’s polar ice caps, a surprising consequence has emerged, one that spins a new twist on our perception of time itself. According to recent research, climate change is redistributing mass on our planet enough to perceptibly alter its rotation. This shift has implications not only for the scientific community but also for the precision required in our global timekeeping systems.
The science underpinning this phenomenon is as fascinating as it is complex. Duncan Agnew, a geophysicist at the Scripps Institution of Oceanography at the University of California San Diego, equates the Earth’s dynamic to a figure skater’s pirouette: “If you have a skater who starts spinning, if she lowers her arms or stretches out her legs, she will slow down.” As the ice at the poles melts, water redistributes primarily toward the equator, thus altering Earth’s angular velocity.
This redistribution of mass due to polar ice melt has a measurable impact on the Earth’s rotation, a concept that has intrigued scholars and scientists for millennia. Agnew notes, “It’s kind of impressive, even to me, we’ve done something that measurably changes how fast the Earth rotates,” underscoring the unprecedented scale of human influence on planetary forces.
This deceleration of Earth’s rotation due to climate change has delayed the possibility of a “negative leap second,” an adjustment that might become necessary to keep Universal Coordinated Time (UTC) in sync with the Earth’s rotation. Traditionally, Earth’s rotation has been slowing over time due to natural factors, necessitating the addition of leap seconds to maintain the precision of atomic clocks.
“What you’re doing with the ice melt is you’re taking water that’s frozen solid in places like Antarctica and Greenland, and that frozen water is melting, and you move the fluids to other places on the planet,” said Thomas Herring, a professor of geophysics at the Massachusetts Institute of Technology who was not involved in the new study. “The water flows off towards the equator.”
Timekeepers initially anticipated the need to subtract a second as soon as 2026, but the continuing loss of polar ice has pushed this date back. “The melting of polar ice has counteracted that trend and forestalled any decision point about a negative leap second,” Agnew says, estimating that this climate change effect has delayed the need for such an adjustment by three years.
However, introducing a negative leap second is not without its complications. It could disrupt vital computer networks, satellite systems, and financial transactions which depend on extremely precise timing. As a result, global timekeepers agreed in 2022 to phase out the leap second by 2035, allowing universal time to drift away from Earth’s rotational pace, ultimately settling for a more relaxed synchronization that could extend up to a minute before a leap minute becomes necessary.
Relevant articles:
– Melting polar ice is slowing the Earth’s rotation, with possible consequences for timekeeping
– Climate change is altering Earth’s rotation enough to mess with our clocks, The Washington Post, Wed, 27 Mar 2024 17:36:05 GMT
– Climate change is messing with how we measure time: Study, Phys.org, Wed, 27 Mar 2024 18:19:32 GMT
– Global Warming Is Slowing the Earth’s Rotation, Scientific American, Wed, 27 Mar 2024 17:20:07 GMT