Time is running out in the fight against the climate crisis, and new research suggests that the melting of polar ice caps is having a tangible impact on our planet's rotation. A study published on Monday in the Proceedings of the National Academy of Sciences reveals that the loss of ice from Greenland and Antarctica is causing Earth to spin more slowly, thereby increasing the length of days at an \"unprecedented\" rate.
Co-author Surendra Adhikari from NASA's Jet Propulsion Laboratory explained that water redistribution from the polar regions adds mass around the equator. \"It's like when a figure skater does a pirouette, first holding her arms close to her body and then stretching them out,\" said Benedikt Soja of ETH Zurich. \"The initially fast rotation becomes slower because the masses move away from the axis of rotation, increasing physical inertia.\"
While Earth is often thought of as a perfect sphere, it is actually an \"oblate spheroid,\" slightly bulging at the equator. This shape is constantly changing due to daily tides, tectonic shifts, and sudden events like earthquakes and volcanoes. The study employed advanced observational techniques such as Very Long Baseline Interferometry and the Global Positioning System to measure variations in Earth's orientation and day length with high precision.
The implications of a slowing Earth are far-reaching, particularly for space navigation. Currently, the moon's gravitational pull causes a gradual deceleration of Earth's rotation, lengthening days by about 2.40 milliseconds per century. However, the new study warns that continued greenhouse gas emissions could accelerate this process, making days longer by 2.2 milliseconds by the year 2100 under a high emissions scenario.
While a few milliseconds may seem negligible, Adhikari notes that even minor deviations can have significant consequences for space communication and navigation. Precise orientation is crucial for maintaining accurate communication with spacecraft like the Voyager probes, where tiny errors can lead to large discrepancies over time.
As the climate crisis continues to reshape our planet, understanding its impacts on fundamental aspects like Earth's rotation underscores the profound interconnectedness of environmental and technological systems.
Reference(s):
cgtn.com
