Most of us grew up believing that Earth is a perfect sphere, but in reality, our world is more of an oblate spheroid. It behaves like a piece of clay squeezed between two fingers, featuring a noticeable bulge at the equator and flatter regions at the poles. However, new research published in the journal JGR Solid Earth reveals that this geometry is shifting. Driven by fossil fuel pollution and rising global temperatures, the planet’s solid surface is becoming rounder at an increasingly rapid pace.
Christopher Kotsakis, a professor of geodesy at the Aristotle University of Thessaloniki, discovered this trend by developing a new way to analyze satellite data. His findings show that as polar ice sheets melt and lose mass, the immense pressure on the poles decreases, causing the crust to slowly lift upward. Simultaneously, as that melted ice flows toward the equator as water, it adds weight and pressure to the center of the globe, causing the equatorial bulge to shrink. Between 2011 and 2015 alone, the poles rose by fractions of an inch annually while the equator contracted.
While these measurements might seem insignificant given the massive scale of the Earth, Kotsakis notes that the speed of this transformation is accelerating every decade. This process highlights a sobering reality about human impact on nature. Beyond just changing weather patterns or sea levels, human activity is now altering some of the most fundamental physical properties of our home, including its actual shape and potentially its rotation and gravity.
It is worth noting that this shift applies specifically to Earth’s solid crust; when you factor in the accumulating ocean water at the equator, the watery silhouette of the planet tells a different story. Regardless, scientists say these geological shifts do not pose an immediate threat to survival. Instead, they serve as a profound indicator of how deeply human driven warming can reshape a planet from its very core outward.