Climate change is delaying world clocks' need for a 'negative leap second'

[Uncle Joe]

How is climate change involved?

First things first: Earth's rotation isn't neat like a well-spun top. There's a distinct wobble — and it can be affected by a number of factors, from powerful earthquakes to what's going on in the planet's core to how water is distributed.

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Decades ago, scientists noticed the Earth was slowing down. But more recently, they've seen the planet's rotation speeding up. In the summer of 2022, NPR even noted one of the shortest days ever recorded.

And here's where things get a bit weird. Human-induced climate change actually acts to slow down the planet's rotation, Agnew says, because when ice melts at the poles, the planet gets a bit more oblong — wider at the equators — and less spherical. That means Earth spins a little slower, like when an ice skater holds their arms out, rather than pulling them in.

The net result for timekeepers, the new research says, is that climate change seems to have delayed the potential need for a negative leap second, at least for a bit.

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https://www.npr.org/2024/03/30/1241674216/climate-change-time-negative-leap-second