Climate change affects Earth’s rotation and timekeeping – study

The melting of glaciers slows down the Earth’s rotation so much that the next “leap second” will be delayed by three years.

This second is sometimes added to Coordinated Universal Time to synchronize it with the Earth’s rotation, which is erratic and slows over the centuries.

“The ice has melted enough to change sea levels enough that we can see how that has affected the speed of the Earth’s rotation.” – said Duncan Agnew, a geophysicist from the Scripps Institution of Oceanography in La Jolla (California). The results of his research published in the journal Nature.

Global warming may lead to the fact that the next “leap second” will not have to be added until 2029, instead of 2026, as previously planned.

According to researchers, “leap seconds” can create problems for computing systems, so scientists plan to get rid of them no earlier than 2035.

They also fear that the next second may be “negative” – ​​it will have to be skipped, not added.

“We don’t know how to deal with missing one second. That’s why metrologists are worried.” – said Felicitas Arias, former director of the time department of the International Bureau of Weights and Measures in Sèvres (France).

She also noted that the three-year delay is “good news” because even if the “negative” leap second is still needed, it will be used later and there will be fewer of them until 2035.

But this should not be seen as an argument in favor of global warming, he noted Duncan Agnew.

Many metrologists predicted that leap seconds would only be added as the Earth’s rotation slowed over the years, meaning that sometimes a minute in Coordinated Universal Time would have to last 61 seconds for the Earth to catch up. This reduction in the planet’s rotation speed is caused by the Moon’s attraction to the oceans.

The analysis also shows that 1.4 billion years ago, a day lasted only about 19 hours. This indicates that the Earth’s rotation has slowed down over millions of years.

According to Agnew, currents in the planet’s liquid core affect the Earth’s rotation speed, which since the 1970s has led to an increase in the rotation speed of the outer crust. Considering the fact that now the Earth rotates more slowly, “leap seconds” need to be added less often. If the rotation continues to slow, such seconds may not be needed at all. This may happen later than previously thought.

The scientists found that without the melting of the ice, the negative leap second would have been needed three years earlier.

“Human activity has a strong impact on climate change. Delaying the leap second is just one example,” – noted Jianli Chen, a geophysicist from the Hong Kong Polytechnic University.

Leap seconds are already a “big problem” because in a society that is increasingly based on precise time, they lead to serious failures in computing systems, says Elizabeth Donley, who heads the time and frequency division at the National Institute of Standards and Technology in Boulder, S.C. Colorado.

An unprecedented negative leap second could be even worse.

“All existing computer codes ignore it,” – said the scientist.

Calculations assume that Earth’s acceleration will continue at current levels, but activity in the inner core is nearly impossible to predict, scientists say.

Agnew hopes that awareness of the impact of climate change on time management will motivate people to take action.

We will remind, by the year 2100 almost half of the Earth’s territory can enter to new climatic zones.