Climate Change melting polar ice caps and increasing earth’s day length : Study

By Aayushi Sharma

A recent study published in Proceedings of the National Academy of Sciences shows that the melting of polar ice caps is causing our planet to rotate more slowly, leading to an unprecedented increase in the length of days. The research also found that the water flowing from Greenland and Antarctica is resulting in more mass around the equator, co-author Surendra Adhikari of NASA’s Jet Propulsion Laboratory told AFP. 

In recent decades, Climate Change has accelerated the melting of glaciers and polar ice sheets, resulting in rising sea levels. This movement of mass from the poles to the equator has notably increased the Earth’s oblateness and length of day (LOD) since 1900. 

Daily tidal forces exert a significant influence on Earth’s shape. The gravitational pull from the moon and the sun creates tides that not only affect the oceans but also the Earth’s crust. These daily tides cause slight but measurable deformations in the planet’s shape. As the water in the oceans shifts, so does the weight distribution on the Earth’s surface, leading to subtle changes in its form. Climate change led to extreme weather conditions around the world causing a disturbance in these natural processes.

If Earth rotates more slowly, the length of a day increases by a few milliseconds beyond the standard 86,400 seconds. Currently, the primary cause of this slowdown is the Moon’s gravitational pull, which exerts “tidal friction” on the oceans, leading to a gradual deceleration of 2.40 milliseconds per century over millions of years. 

However, the study reveals a surprising conclusion: if humans continue to emit greenhouse gases at a high rate, the warming climate’s impact will surpass that of the Moon’s pull by the end of the 21st century. From 1900 to the present, climate change has extended the length of days by approximately 0.8 milliseconds. Under a worst-case scenario of high emissions, climate change alone could increase the length of days by 2.2 milliseconds by 2100, compared to the same baseline.

References:

https://www.pnas.org/doi/abs/10.1073/pnas.2406930121

https://www.sciencealert.com/earths-days-to-grow-at-an-unprecedented-rate-as-polar-ice-melts

https://www.pexels.com/photo/eye-of-the-storm-image-from-outer-space-71116

https://www.pexels.com/photo/sun-behind-a-round-planet-12498767