The Magnetosphere

Magnetic Field Is Fading, but No Dire Effects Are Foreseen

Scientists have known for some time that the magnetic field is in fact collapsing, at a rate faster than it would if flows of molten iron in the core had stopped completely.

There was a cool NOVA episode on this very topic. Bottom line is we are overdue by tens of thousands of years for a flip of the poles. The theory is that the field will weaken, then flip, then go back to normal. Rinse, lather, repeat. It won't happen in my lifetime (probably), but it will happen soon, geologically speaking of course.