I wanna know, what will be the effect of magnetic pole reversal, on earth?

well... most of our GPS systems will need recallibration for sure!

and the Aurora borialis will certainly move further South and create all types of electrical mayhem.

 

there are much further refined problems that don`t spring to mind at this time, but non the less they exist.

Why will GPS need recalibration? Latitude and longitude do not depend on the magnetic fields. Compasses will be useless, but not GPS.

There have been a number of threads that have broached this subject. (ignore the sun polarity thread and the ones in pseudoscience/metaphysics)