Global warming's unexpected impact: Earth's rotation slows, time adjustment debated

Glaciers melting at both poles have led to a slight slowdown in the Earth's rotation. This startling conclusion was reached in an analysis published by Nature magazine, which highlighted the impact of global warming on global time measurement.

Scientists have found that global warming causes glaciers at both poles to melt, slowing the Earth's rotation. According to an analysis detailed on the TVN Meteo website and published in the "Nature" journal, this deceleration is significant enough to affect how we measure time.

Since the late '60s, Universal Coordinated Time (UTC) has been the standard for determining time zones worldwide, relying on the precision of atomic clocks. However, the Earth's rotation varies, leading to discrepancies between UTC and Earth's rotational time. Factors such as sea tides, the Moon's gravitational pull, and major landmass movements can influence this rotation. In response to the gradual elongation of Earth's rotational period by a few milliseconds per century, the leap second system was implemented in 1972 to keep UTC and solar time aligned, with 27 leap seconds added since then.

Until 2020, the Earth's slower rotation was attributed to tidal friction on the ocean floors, driven by the Moon's gravity. However, recent analyses pinpoint glacier melt as a new culprit, with water redistribution towards the equator slowing Earth's spin. According to Duncan Agnew, a geophysicist at the Scripps Institution of Oceanography in California, the human contribution to this change is astonishing.

"The comparison reminds me that humans have significantly altered the Earth's rotation," Duncan Agnew remarked, taken aback by the findings.

Ted Scambos, a glaciologist at the University of Colorado in Boulder, likened the Earth to a skater on an ice rink. A skater spins faster with arms raised but slows down when lowering them. Similarly, Earth's rotational dynamics change with mass redistribution.

Interestingly, the trend of Earth's deceleration has recently shown signs of reversal due to processes within the planet's core. This reversal poses new challenges for time calculation, potentially disrupting information systems. Experts are considering ending the practice of adding leap seconds by 2035, especially concerning the eventual need to subtract a second.