Groundwater Extraction and the Earth’s Tilt

by Suzanna Schofield

Groundwater is a resource that many communities around the world depend on. It provides more than 70% of the global water consumption. However, recent reports have shown that groundwater extraction is turning our planet’s axis.

Over the millions of years that Earth has existed, groundwater has been collecting in aquifers and wells. Until only recently, we believed that we would be able to depend on these aquifers and wells to provide water for the places we live. However, a report in 2015 from the University of Victoria titled “The global volume and distribution of modern groundwater” found that less than 6% of groundwater is replenished and renewed within a 50-year time span. This provides an argument for the fact that groundwater may not be as renewable as originally thought.

In the past four decades, groundwater-level declines have accelerated in 30% of the world’s regional aquifers. Many of these regions are dry and have extensive croplands, showing that the future of these regions, regarding their populations and economies, is under threat. In Delhi for example, 99.1% of the groundwater had been extracted in 2023.

This groundwater extraction is causing not only harmful regional effects but is also shifting Earth’s pole. A group of scientists built a model for polar motion where they accounted for factors such as reservoirs filling because of dams and ice sheets melting as the shift in the weight of water around the globe and the increase in sea level rise is contributing to shifts in the poles. However, dams and ice sheets melting do not alone make up for the observed polar motion.

It wasn’t until the scientists combined the model with a climate model estimate for the period 1993-2010 of a total groundwater depletion of 2,150 GT on the predicted polar motion that aligned with observations of polar motion. The 2150 GT of groundwater extraction has redistributed that weight to the world’s ocean resulting in Earth’s poles shifting nearly 80 centimeters, as well as an increase of 6 millimeters to global sea level rise in the same time span. A significant amount of this groundwater extraction happened in northwestern India and the western United States.

The polar shift is too small to affect weather or seasons, but it does have implications for how continued groundwater extraction will raise sea levels. And rising sea levels, even 6mm, can lead to increased coastal flooding, erosion, and damage to communities.

Works Cited

●       Cornwall, Warren. “Humanity’s Groundwater Pumping Has Altered Earth’s Tilt.” Science, 16 June 2023, https://www.science.org/content/article/humanity-s-groundwater-pumping-has-altered-earth-s-tilt

●       Dixit, Kushagra. “Groundwater: Delhi Groundwater Crisis: 99.1% of Available Groundwater Extracted | Delhi News - The Times of India.” The Times of India, Times of India, https://timesofindia.indiatimes.com/city/delhi/delhi-groundwater-crisis-991-of-available-groundwater-extracted/articleshow/111095835.cms. Accessed 9 Apr. 2025.

●       Gleeson, Tom, et al. “The Global Volume and Distribution of Modern Groundwater.” Nature Geoscience, no. 2, Springer Science and Business Media LLC, Nov. 2015, pp. 161–67. Crossref, doi:10.1038/ngeo2590.

●       Jasechko, Scott, et al. “Rapid Groundwater Decline and Some Cases of Recovery in Aquifers Globally.” Nature, no. 7996, Springer Science and Business Media LLC, Jan. 2024, pp. 715–21. Crossref, doi:10.1038/s41586-023-06879-8.

●       Seo, Ki‐Weon, et al. “Drift of Earth’s Pole Confirms Groundwater Depletion as a Significant Contributor to Global Sea Level Rise 1993–2010.” Geophysical Research Letters, no. 12, American Geophysical Union (AGU), June 2023. Crossref, doi:10.1029/2023gl103509.

●       Zekster, Igor, and Lorne Everett. “Groundwater Resources of the World and Their Use.” UNESCO, 2004.