Climate Change Could Affect Global Timekeeping气候变化或将影响全球计时

Climate change is affecting the speed of the Earth’s rotation and could impact how we keep time， a study says. Global warming is already affecting global timekeeping， says the study published in the journal Nature.

Coordinated Universal Time （UTC）—which is used by most of the world to regulate clocks and time—is calculated by the Earth’s rotation. But the Earth’s rotation rate is not constant and can therefore have an effect on how long our days and nights are. Changes to the planet’s liquid core have meant the Earth has been spinning slightly quicker.

Since the 1970s， to correct for this， about 27 leap seconds have been added to the global clock， with timekeepers planning on subtracting a second for the first time in 2026. This is known as a “negative leap second”. However， the study finds that ice melting caused by climate change has partly offset that acceleration. Ice sheets are now losing mass five times faster than they were 30 years ago， meaning that the negative leap second change will not be needed until 2029， the study suggests.

一项研究称，气候变化正在影响地球的自转速度，并可能影响人类的计时方式。这项发表在《自然》杂志上的研究指出，全球变暖已经在影响全球计时。

“协调世界时”是根据地球自转计算出来的，世界上大多数国家都用它来调节时钟和时间。但地球的自转速度并不是恒定的，因此会对我们的昼夜长短产生影响。地球液态的地核发生变化意味着地球的自转速度略快。

为了纠正这一现象，自20世纪70年代以来，全球时钟已经增加了约27个闰秒。计时员计划在2026年首次减少一秒，这被称为“负闰秒”。然而，研究发现，气候变化导致的冰雪融化在一定程度上抵消了这一加速。研究表明，现在冰原质量损失的速度是30年前的5倍，这意味着可能直到2029年才需要负闰秒的变化。

“It’s kind of impressive， even to me. We’ve done something that measurably changes how fast the Earth rotates，” said Duncan Agnew， the author of the study. The negative leap second has never been used before and， according to the study， its use “will pose an unprecedented problem” for computer systems across the world.

“This has never happened before，” Mr Agnew added. “Many computer programs for leap seconds assume they are all positive， so these would have to be rewritten.”

There has been some skepticism of the study， however. Demetrios Matsakis， former chief scientist for time services at the US Naval Observatory， said， “Earth is too unpredictable to be sure if a negative leap second would be needed any time soon.”

这项研究报告的作者邓肯·阿格纽说：“即使对我来说，这也是令人印象深刻的。我们已经做了一些明显改变地球自转速度的事情。”负闰秒以前从未使用过，根据这项研究，负闰秒的使用将给全球的计算机系统“带来前所未有的难题”。

阿格纽先生补充说：“这种情况以前从未发生过。许多计算机程序都默认闰秒是正数，因此这些程序必将重写。”

然而，也有一些人对这项研究持怀疑态度。美国海军天文台负责时间服务工作的前首席科学家德米特里奥斯·马萨基斯说：“地球实在是难以预测，因此在不久的将来是否需要负闰秒还无法确定。”