I’ve read and seen a couple of videos about how Earth’s polarity shifts or switches over time. Apparently, each time there is a shift in polarity there will be more frequent earthquakes and other phenomena. Haha. Oh, boy! That’s just what we need.....
Yeah, just did some digging back. Came up with Wiki...lots of big earthquakes in 1972.
A rotation swap and a polarity swap are two different things. A polarity swap causes a weak and erratic magnetic field lasting hundreds of years or more. The last known polarity swap was about 780 million years ago. The magnetic field protects us from solar winds (radiation). Nobody knows for sure how dangerous the conditions would be. Bottom line however, if there was no magnetic field, there would be no life as we know it. No magnetic field = dead planet.