Well, the only problem, is that there really isn't evidence that a polar shift would result in the imminent collapse of the earth's magnetic sphere or the like... More recent evidence on the sea floor, has shown evidence that the Earth's magnetic spheres have changed several times, as observable from the formation of continental plates thsemselves, and certain characteristics in the sedimentary rock that was formed over time...
Think, for instance how with ice core samples, we can do some dating to deterine when ice at a given depth was formed, and then from there extrapolate some information on the Earth's atomosphere (and the composition of gases in it) over those periods of time. I'd have to look for further info (as I had seen the program well over a decade ago), but as I remember the last polar shift was recent enough in geolotic history for Homo Sapiens of one sort or another to have lived through it.
http://pubs.usgs.gov/publications/text/developing.html
Beginning in the 1950s, scientists, using magnetic instruments (magnetometers) adapted from airborne devices developed during World War II to detect submarines, began recognizing odd magnetic variations across the ocean floor. This finding, though unexpected, was not entirely surprising because it was known that basalt -- the iron-rich, volcanic rock making up the ocean floor-- contains a strongly magnetic mineral (magnetite) and can locally distort compass readings. This distortion was recognized by Icelandic mariners as early as the late 18th century. More important, because the presence of magnetite gives the basalt measurable magnetic properties, these newly discovered magnetic variations provided another means to study the deep ocean floor.
Early in the 20th century, paleomagnetists (those who study the Earth's ancient magnetic field) -- such as Bernard Brunhes in France (in 1906) and Motonari Matuyama in Japan (in the 1920s) -- recognized that rocks generally belong to two groups according to their magnetic properties. One group has so-called normal polarity, characterized by the magnetic minerals in the rock having the same polarity as that of the Earth's present magnetic field. This would result in the north end of the rock's "compass needle" pointing toward magnetic north. The other group, however, has reversed polarity, indicated by a polarity alignment opposite to that of the Earth's present magnetic field. In this case, the north end of the rock's compass needle would point south. How could this be? This answer lies in the magnetite in volcanic rock. Grains of magnetite -- behaving like little magnets -- can align themselves with the orientation of the Earth's magnetic field. When magma (molten rock containing minerals and gases) cools to form solid volcanic rock, the alignment of the magnetite grains is "locked in," recording the Earth's magnetic orientation or polarity (normal or reversed) at the time of cooling.
But we're talking a TV show, so that point is rather irrelavent. If that's the idea the show writers had in mind, that's the idea they had in mind.
I refuse to read any theories that may potentially be spoilers.
