When I first heard about this, it brought to mind this violent flip, like the word.
I have no idea what will happen as far as catastrophic events, but I do know that the field slowly changes north to south, south to north. There is no violent flipping involved, little pieces of the north start changing, and little pieces of the south start changing, and it spreads out on both sides until they are the opposite they once where.
Should be interesting if it does happen in my lifetime. I am especially interested to see what kind of psychological effects it will have on people. Our brains are cool little low charge electrical devices.
Never be afraid to do the righteous thing, nothing righteous is ever easy.