Melting ice at the poles is lengthening the days, a study has shown.
According to a study published Monday, the water resulting from melting poles is largely found in the equatorial regions. This change in the distribution of masses on Earth contributes to slowing the speed of our planet’s rotation.
Climate change, through melting ice at the poles, is slowing the Earth's rotation ever so slightly, increasing the length of the day by a few milliseconds, a study published Monday, July 15, 2018, revealed. Proceedings of the National Academy of Sciences.
Antarctica, Greenland and many glaciers are located “in the polar regions,” study co-author Surendra Adhikari told AFP.
“Like a figure skater does a spin”
The water that melts due to global warming is largely found “in the tropics,” and this change in the distribution of masses on the planet “affects the way the Earth rotates.” That means: a little slower.
“It’s like an ice skater doing a spin on the ice, first putting his arms close to his body and then extending them out,” Benedikt Soja, also a co-author of the study, compares. “The spin is very fast at first, then slows down a little bit.”
This slower rotation lengthens the length of the day very slightly, making it 86,400 seconds in total.
Since 2000, the rate of increase in day length due to climate change has been 1.33 milliseconds per century. If greenhouse gas emissions continue to increase very rapidly, this rate could rise to 2.62 milliseconds per century by 2080 or 2100.
An influence that can exceed that of the moon.
The effect of climate change could exceed that of the Moon, which has also gradually slowed the Earth's rotation over several billion years.
“It was very surprising to see that by the end of the 21st century, in high emissions scenarios, (…) the climate alone could take over the contribution of a phenomenon such as the Earth-Moon dynamics,” commented Surendra Adhikari.
While these changes may seem small, they have “huge implications for terrestrial and space navigation,” for example, sending signals to distant sensors, he said.
According to Benedict Soja, this study also shows something more symbolic: “Humans’ impact on the planet is greater than we think.”