2024-07-16 17:31:02
washington: The climate crisis has emerged as a major challenge for the world in recent times. The melting of ice sheets and global glaciers is not only increasing the sea level, but the days are also getting longer. A new research shows that the melting of polar ice is causing the Earth to rotate more slowly, due to which the length of days is increasing at an ‘unprecedented’ rate. Surendra Adhikari of NASA’s Jet Propulsion Laboratory has said that the research paper published in the Proceedings of the National Academy of Sciences shows that there is more mass around the equator due to the water flowing from Greenland and Antarctica.
According to NDTV report, talking about the reason for the increase in the day, Benedict Soja of ETH Zurich said, ‘Usually the Earth is considered as a sphere, but it would be more correct to call it an ‘oblate spheroid’, which is somewhat bulged around the equator like a satsuma. Its shape is constantly changing. Due to the effect of daily tides that affect the oceans and the crust. It also changes due to the movement of tectonic plates, earthquakes and volcanoes.
The days are slowly getting longer
Using data collected since 1900, the researchers observed that climate change caused the length of day (LOD) to increase by between 0.3 and 1.0 milliseconds per century during the 20th century. Since the year 2000, this rate has increased to 1.33 milliseconds per century. This significant acceleration is associated with the movement of mass across the Earth’s surface, particularly the melting of polar ice and glaciers, which has accelerated over the past few decades.
The redistribution of mass from melting ice to the oceans changes the shape of the Earth, making it slightly more oblate (flattened at the poles and bulged at the equator). This shift in mass affects the planet’s rotation, causing days to become longer. Research suggests that this mass transport is entirely responsible for the changes observed in the Earth’s shape over the past thirty years.
The days will increase in the coming years
Scientists have measured the effect of glacial isostatic adjustment (GIA). The Earth’s surface is slowly rebounding after being compressed by ice sheets during the last ice age. This rebound effect is slowing the rate at which days are getting longer. By combining the effects of GIA and lunar tidal friction (the gravitational pull between Earth and the moon), the researchers can explain the steady increase in day length observed over the past three millennia, before the significant impact of contemporary climate change.
Projections under high-emissions scenarios indicate that the rate of climate-induced day lengthening could reach 2.62 milliseconds per century by 2100. This would make climate change the most important cause of long-term changes in day length. They point to the profound impact of human activities on Earth, even showing up in subtle changes to the length of our days.