美国加州大学Agnew Duncan Carr报道了由于全球变暖而推迟的全球计时问题。相关论文于2024年3月27日发表在《自然》杂志上。

据介绍，时间与地球自转的历史关联，意味着协调世界时(UTC)与地球自转密切相关。由于旋转速率不是恒定的，UTC包含不连续(闰秒)，这使其在计算机网络中的使用变得复杂。自1972年以来，所有的UTC不连续点都需要添加一个闰秒。

研究使用卫星重力测量的方法表明，格陵兰岛和南极洲冰融化的增加使得地球的角速度比以前更快地降低。从观测到的角速度中去除这种影响表明，自1972年以来，地球液态核心的角速度一直在以恒定的速率下降，这使得地球其他部分的角速度稳步增加。

外推地核和其他相关现象的趋势来预测未来地球的方向表明，按照现在的定义，到2029年，UTC将需要一个负间断。这将给计算机网络计时造成前所未有的问题，可能需要比计划更早地更改UTC。如果最近极地冰融化没有加速，这个问题将会提前3年出现，全球变暖已经影响到全球的计时。

附：英文原文

Title: A global timekeeping problem postponed by global warming

Author: Agnew, Duncan Carr

Issue&Volume: 2024-03-27

Abstract: The historical association of time with the rotation of Earth has meant that Coordinated Universal Time (UTC) closely follows this rotation. Because the rotation rate is not constant, UTC contains discontinuities (leap seconds), which complicates its use in computer networks. Since 1972, all UTC discontinuities have required that a leap second be added. Here we show that increased melting of ice in Greenland and Antarctica, measured by satellite gravity, has decreased the angular velocity of Earth more rapidly than before. Removing this effect from the observed angular velocity shows that 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 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 is planned. If polar ice melting had not recently accelerated, this problem would occur 3years earlier: global warming is already affecting global timekeeping.

DOI: 10.1038/s41586-024-07170-0

Source: https://www.nature.com/articles/s41586-024-07170-0