I assume you realise it is the magnetic poles that reverse, not the geographical ones. The Earth itself does not flip over! Your compass does not point to the geographical North Pole anyway - the magnetic poles are always on the move and shift a bit each year.
Some people have some strange ideas (concepts) of what is involved during such reversals
With effects, that may range beyond the EMP register, of Nuclear blasts
And, as our blood cells contains 'iron'
what might then occur (happen (to us) as those cells are propelled
by the transience of the poles to negative from positive and vice versa
like: iron filings under the influence of a powerful magnet
Electro Magnetic Flux will be incredibly strong and unpredictable
Car batteries and electrical circuitry (components) would not fare well, during the reversal
Transformers / Generators could go into meltdown
Consider, what happens to the 'iron content' of the upper and lower crusts during such geomagnetic upheaval
The earth's axis does vary (agreed) and it is 'quite a wobble' and beyond doubt
causes a great deal of tectonic plate movement > subduction, collisions, earthquakes and eruptions (worldwide)
My compass, points to magnetic North (at present @ 7 degrees from geographical North)
ETA:
The cells of our bodies are tied together by electro-mechanical bonds
what happens to those, when 'lightning' passes through them ?
Just fluxing lyrical
