Melting Ice Caps Slow Earth’s Spin, Lengthening Our Days
Time is of the essence when it comes to the climate crisis, and now, new research suggests that climate change is literally slowing down time.
A study published in the Proceedings of the National Academy of Sciences reveals that the melting of polar ice caps is causing Earth to spin more slowly, increasing the length of our days at an unprecedented rate.
According to co-author Surendra Adhikari of NASA’s Jet Propulsion Laboratory, water flowing from Greenland and Antarctica due to ice melt is redistributing mass toward the equator. This redistribution is akin to a figure skater extending her arms to slow her spin.
Co-author Benedikt Soja of ETH Zurich explains, “The initially fast rotation becomes slower because the masses move away from the axis of rotation, increasing physical inertia.”
While we often think of Earth as a perfect sphere, it’s actually an oblate spheroid—slightly bulging at the equator. This shape is constantly changing due to factors like ocean tides, tectonic plate movement, and dramatic events such as earthquakes and volcanic eruptions.
The researchers utilized observational techniques like Very Long Baseline Interferometry and the Global Positioning System to measure Earth’s rotation with extreme precision, even analyzing ancient eclipse records dating back millennia.
Implications for Space Travel
An increased length of day means that each day becomes a few milliseconds longer than the standard 86,400 seconds. While the gravitational pull of the moon, causing tidal friction, has long been known to slow Earth’s rotation by approximately 2.4 milliseconds per century, the study finds that climate change could have an even greater impact.
Adhikari notes that if greenhouse gas emissions continue at a high rate, the effect of a warming climate on Earth’s rotation could surpass that of the moon’s pull by the end of the 21st century. Since 1900, climate change has added about 0.8 milliseconds to each day, and under a worst-case scenario, days could be 2.2 milliseconds longer by 2100 due to climate alone.
While this change is imperceptible to humans, it has significant implications for space and Earth navigation. Precise knowledge of Earth’s orientation is crucial for communicating with spacecraft, such as the Voyager probes now beyond our solar system. Even a tiny deviation can result in communication errors over vast distances.
As we continue to grapple with the effects of climate change, understanding these subtle yet profound impacts on our planet becomes increasingly important.
Reference(s):
cgtn.com
