Ice sheets melting could delay the requirement for a "negative leap second"

 We might have to postpone adding that "negative leap second" in order to maintain clocks in sync with Earth's rotation since glaciers are melting so quickly.

Credit: Indian express

It is common knowledge that sea levels and weather patterns have been affected by climate change. However, a recent study that was published in the scientific journal Nature suggests that it might even be changing the way we tell time.

According to the study, rising temperatures are causing glaciers and ice sheets in Greenland and Antarctica to melt more quickly, which is causing all that more liquid to spread out across the earth and shift weight. This results in a very tiny slowing down of the Earth's axis rotation.

This rate of rotation serves as the foundation for our clocks and calendars, which are controlled by scientists who determine Coordinated Universal Time (UTC). However, there hasn't been an entirely consistent rotation. In truth, the Earth has been rotating slightly faster than usual for the past few decades.

Timekeepers around the world have added a "leap second" to clocks on a 27-time basis since the 1970s in order to accommodate for that speedup. In 2026, it was intended to deduct that leap second for the first time—a change they dubbed the "negative leap second."

However, the accelerated melt from Greenland and Antarctica may have worked as a brake, slowing the rotation back down just enough that we might not require that negative leap second until 2029 or later, according to this new research.

Duncan Agnew of the University of California, San Diego, who wrote the paper, told AFP that he found it "quite impressive" that they were able to measure the Earth's rotational speed. Unprecedented events are taking place.

He cautions that if and when we do have to make that negative leap second adjustment, it might seriously interfere with computer systems that aren't built to handle that kind of time subtraction.

However, not everyone is persuaded. The magazine was informed by Demetrios Matsakis, the former chief scientist for time services at the US Naval Observatory, that it is too difficult to determine when (or if) we would use that negative leap second in the near future due to the unpredictability of Earth's rotation.