The Earth could be about to turn upside down. The planet's magnetic field is showing signs of wanting to make a gigantic somersault, so that magnetic north heads towards Antarctica, and magnetic south goes north. Compasses will point the wrong way, and migrating birds, fish and turtles are going to be very confused.
Just when this will happen, how long it will take and what the consequences will be, is difficult to fathom. What is not in doubt, though, is that it will happen. About every half a million years or so, the Earth's magnetic field flips upside down.
Two overviews related to the evidence found in April, that the magnetic pole reversal had begun.