For the past two decades, the rotation of the Earth has shown unusual behavior. Scientists have now identified a surprising cause for this phenomenon: the loss of water from the land.
A recent study published in Science reveals that significant changes in the Earth’s axis since the early 2000s, resulting in a wobble of about 45 cm, were not due to changes in the core, ice loss, or glacial rebound. Instead, they were caused by underestimated changes in soil moisture across the planet.
Between 2000 and 2002, over 1,600 Gigatonnes of water were lost from the soil worldwide. This water, when discharged into the ocean, impacted the Earth’s balance and influenced its rotation.
According to Professor Clark Wilson, a geophysicist at the University of Texas at Austin and co-author of the study, there was a period in the early 2000s when significant water losses occurred from the continents, aligning with certain climate models’ predictions.
Research led by Professor Ki-Weon Seo from Seoul National University in Korea used satellite radar data and soil moisture models to track changes in Earth’s water reservoirs from the late 20th to early 21st centuries. They discovered a sudden drop in soil moisture between 2000 and 2002, contributing to a yearly rise in the global sea level.
This decrease in soil moisture continued from 2003 to 2016, with an additional loss of 1,000 Gigatonnes of water. By 2021, soil moisture levels had still not recovered, indicating a significant and lasting shift in Earth’s land water storage.
The study emphasizes how changes in terrestrial water, particularly soil moisture, can influence Earth’s axis and rotation, leading to observable effects on the planet’s vital signs. The researchers suggest that this trend of drying soil is likely irreversible and could have far-reaching consequences on global water security, agriculture, ecosystems, and climate patterns.
Experts Involved
Clark Wilson: Professor Emeritus at the University of Texas at Austin, specializing in Earth and Planetary Sciences.
Ki-Weon SEO: Associate Professor at Seoul National University with a focus on ice mass losses and sea level rise.
Jay Famiglietty: Global Futures Professor at ASU’s School of Sustainability, specializing in water innovation and sustainable food systems.
This study highlights the importance of improving climate models to better understand and predict future climate conditions in the face of changing water dynamics on Earth.
Source: www.sciencefocus.com
