"The Earth’s magnetic field protects our planet from dangerous solar and cosmic rays, like a giant shield. As the poles switch places (or try to), that shield is weakened; scientists estimate that it could waste away to as little as a tenth of its usual force. The shield could be compromised for centuries while the poles move, allowing malevolent radiation closer to the surface of the planet for that whole time. Already, changes within the Earth have weakened the field over the South Atlantic so much that satellites exposed to the resulting radiation have experienced memory failure."
