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Bhubaneswar: The climate change caused by global warming, which poses a serious threat to life on Earth, is already affecting global timekeeping, a study said.
According to the research study published in Nature, the increased melting of ice in Greenland and Antarctica, measured by satellite gravity, has decreased the angular velocity of Earth more rapidly than before. Since 1972, the angular velocity of the liquid core of Earth has been decreasing at a constant rate that has steadily increased the angular velocity of the rest of the Earth.
Extrapolating the trends for the core and other relevant phenomena to predict future Earth orientation shows that the Coordinated Universal Time (UTC) as now defined will require a negative discontinuity by 2029. This will pose an unprecedented problem for computer network timing and may require changes in UTC to be made earlier than planned.
If polar ice melting had not recently accelerated, this problem would occur 3 years earlier, the study said.
Before 1955, the reliability of any high-quality timescale depended on its synchronization with the Earth’s rotation, which was deemed more consistent than any available oscillator. Hence, the second was defined as a specific fraction of the time taken by Earth to complete one rotation relative to the stars. This count of rotational seconds constituted a timescale known as UT.
However, the introduction of atomic frequency standards utilizing caesium proved far more stable than Earth’s rotation. Consequently, shortly after the announcement of a functional caesium oscillator, a proposal was made to redefine the second based on this frequency, leading to the establishment of a timescale using atomic seconds in 1955. This effort resulted in the creation of an atomic timescale called TAI within a few years. UT and TAI were aligned on 1 January 1958, but they have since diverged due to the Earth’s variable rotation rate. This variability has historically complicated UTC and is anticipated to pose even greater challenges in the future, the study said.
[Disclaimer: This story is a part of ‘Punascha Pruthibi – One Earth. Unite for It’, an awareness campaign by Sambad Digital.]