"...persistent groundwater extraction over more than a decade shifted the axis on which our planet rotates, tipping it over to the east at a rate of about 1.7 inches (4.3 centimeters) per year." By Mindy Weisberger via CNN Image credit: NASA Humans' unquenchable thirst for groundwater has sucked so much liquid from subsurface reserves that it's affecting Earth's tilt, according to a new study. Groundwater provides drinking water for people and livestock, and it helps with crop irrigation when rain is scarce. However, the new research shows that persistent groundwater extraction over more than a decade shifted the axis on which our planet rotates, tipping it over to the east at a rate of about 1.7 inches (4.3 centimeters) per year. That shift is even observable on Earth's surface, as it contributes to global sea level rise, researchers reported in the study published June 15 in the journal Geophysical Research Letters. "Earth's rotational pole actually changes a lot," said lead study