Climate change affects the Earth’s rotation spin making it wobble, which gradually results in increasingly longer days, new studies show.
The studies utilized AI to monitor the effects of human-caused climate change on Earth’s spin, showing that our days are getting longer, which will affect life on Earth in the future.
The results of the studies published on the space.com website show that the wobble has thrown the planet’s orientation out of balance, altering Earth’s spin and subsequently altering its inner core, as well.
This wobble of the planet as it spins and the shift of the axis location is a phenomenon known as polar motion. In the past 120 years, the planet’s axis has meandered by about 30 feet (10 meters).
A day lasts about 86,400 seconds. However, the exact time it takes Earth to complete a single rotation can shift by tiny fractions of milliseconds every year. This is due to a number of factors such as tectonic plate movements, changes to the inner core’s rotation, and gravitational pull from the moon.
The studies show that human-induced climate change can also alter the length of our days, as it affects the planet’s spin and will continue to do so in the coming years. For instance, the melting of huge ice masses at the North Pole, resulting from the planet’s overheating, shifts the balance and thereby the Earth’s spin.
Over the past few decades, global warming has increased the rate of ice loss from Earth’s polar regions. This leads to rising sea levels, with most of the melted ice accumulating near the equator, causing our planet to bulge slightly around the middle. This, in turn, slows the planet’s spin because more weight is distributed farther away from the planet’s center.
AI used in research for climate change effect
In the new study, published on July 15th in the journal Proceedings of the National Academy of Sciences (PNAS), researchers used an advanced artificial intelligence program that combines real-world data with the laws of physics to predict how the planet’s spin will change over time due to climate change.
In a NASA-funded study, researchers noticed an uptick just after 2000 in how fast the day was lengthening. This change correlated with independent observations of the move of melted ice sheets near the equator. For the period from 2000 to 2018, the rate of length-of-day increase due to movement of ice and groundwater was 1.33 milliseconds per century, which is faster than that of any period in the prior 100 years, when it varied from 0.3 to 1.0 milliseconds per century.
The same research team also released another study, published July 12th in the journal Nature Geoscience. The study revealed that the increased volume of water near the equator is moving Earth’s axis of rotation. This is causing the magnetic poles to wobble slightly farther away from the axis every year, thus altering the length of a day.
According to scientists, Earth’s days have always varied in length. Around one billion years ago, our planet likely took only 19 hours to complete a single rotation around the Sun, before slowing to the 24 hours we experience today.
Earth rotation records began being kept in 1960. Data shows that changes in the rotation are happening in a shorter period. In 2020, Earth was spinning more quickly than at any point since 1960. In 2021, however, the planet’s rotation began to slow down again even though the shortest-ever recorded day was in June 2022.
Lunar tidal friction
Earth’s rotation has been slowing for millennia, mainly due to a process known as lunar tidal friction, in which the moon’s gravitational effect on the oceans pulls water away from the poles. This effect increases the duration of a day by around 2.3 milliseconds every century.
The new studies show that climate change is currently lengthening our days by around 1.3 milliseconds every century. However, based on current global temperature models, the researchers predict that this could increase to 2.6 milliseconds per century by the end of the 21st century, making climate change the biggest influence on our planet’s spin.
One of the most likely effects of longer days in the future would be the need to introduce negative leap seconds, meaning that we would occasionally lose a second from some future days to accommodate the lengthening days, similar to how leap years work.
The March study suggests that we may need to introduce this measure as soon as 2029, mainly to make up for the days that have already lengthened over the past few millennia.
In the past, scientists have suggested this introduction could impede on the timekeeping of computers and smartphones. The lag must be taken into account because many modern technologies, including GPS, rely on precise timekeeping.
If concentrations of greenhouse gases in the atmosphere continue to rise, lengthening of day from climate change could amount to as much as 2.62 milliseconds per century. This would be overtake the effect of the Moon’s pull on tides, which has been lengthening Earth’s days by 2.4 milliseconds per century on average.
