Researchers Baffled as One Agricultural Practice Has Tilted Earth’s North Pole by 30 Inches
The chaos theory explains the idea of the butterfly effect to describe how minute changes in one part of the world can produce dramatic outcomes in the other, according to Brittanica. This is mainly explained by how the mere flapping of a butterfly's wings here could trigger a windstorm in a different corner of the globe. Along the same vein, scientists have deduced that extensive irrigation practices in agriculture have measurably tilted the North Pole. A 2023 study used a climate model to estimate the rate at which groundwater depletion and the resulting sea level rise has led to a drift in the Earth’s pole towards the east at a speed of 4.36 cm/year, as published in the journal Advancing Earth and Space Sciences in June of that year.
Among other contributing factors, runoff from irrigation plays a significant role in moving much of the land water to the sea. In fact, it is the second-largest contributor to polar drift after the ongoing rebound of Earth’s surface since the last ice age. The scientists devised computer simulations to study the impact of irrigation in pushing the North Pole by about 78 centimeters from 1993 to 2010. Clark Wilson, a geophysicist at the University of Texas at Austin explained the subtle and noncyclic polar drift caused by the movement of land-based water to the sea. The sources of this land-based water include melting glaciers worldwide, ice sheets in Greenland and Antarctica, and more notably, the irrigation runoff water.
The published paper stated that other studies have found that about 2 trillion metric tons of water from land-based aquifers were shifted to the oceans by irrigation from the said time period. The significant number was sufficient to increase the global sea level by 6 millimeters– this redistribution of water nudged the North Pole over four centimeters annually during the time span of 17 years. The researchers noted that the impact of irrigation was only in the direction of the polar drift rather than the measure. The runoff of ice meltwater from Greenland and Antarctic ice sheets in addition to the irrigation water pushed the North Pole 1.6 meters to the east coast of Greenland.
Whereas, it would have moved to the center of Greenland without the impact of irrigation but by the same distance. The changes in polar drift caused by irrigation are permanent though and continue to grow annually. Jay Famiglietti, a hydrologist at Arizona State University in Tempe, said, “It’s important to realize that water is heavy, and when it moves around it’s going to affect Earth’s rotation," per Science News. It is also worth noting that polar drift is a natural phenomenon and scientists are aware of the movements in the North Pole as it wanders across the Arctic seascape in a cyclic motion of a few diameters.
This movement is further affected by seasonal weather patterns with temperature differences and the salinity of ocean water also causing long-term variations. This cyclic drift results in a 14-month oscillation called the Chandler Wobble, per the study. Therefore, the impact of irrigation– one of the widely used agricultural practices across the globe, is well-defined in the overall global sea level rise and groundwater depletion further affecting the movement of the North Pole. It also influences the temperature in the local areas, cooling the region by certain degrees and also, increasing humidity levels affecting rainfall.