Climate change is causing the North Pole's location to drift, owing to subtle changes in Earth's rotation that result from the melting of glaciers and ice sheets. The finding suggests that monitoring the position of the pole could become a new tool for tracking global warming.Computer simulations had suggested that the melting of ice sheets and the consequent rise in sea level could affect the distribution of mass on the Earth's surface. This would in turn cause the Earth's axis to shift, an effect that has been confirmed by measurements of the positions of the poles.
Now, Jianli Chen of the University of Texas at Austin and colleagues have shown that melting due to our greenhouse-gas emissions is making its own contribution to the shift.
The wobble in Earth's axis of rotation is a combination of two major components, each with its own cause. One is called the Chandler wobble and is thought to arise because the Earth is not rigid. Another is the annual wobble, related to Earth's orbit around the sun.