Yeah, that could be. I think there are 2 things that could trigger it. A meteor strike or a pole switch. The sun switches poles every few years. If the earth's core is like the suns core, maybe it flips every few thousand years. Or maybe there's another body we're not aware of that is highly electromagnetic that's on a long very elliptical orbit. It would explain the asteroid belt, Uranus on it's side, Pluto on it's wild orbit, and maybe even our moon. Our earth is like a big magnet, if another powerful magnet were introduced and got relatively close to the earth, the earth's core would try to align with it.
It's got to be something. The mammoths are frozen standing up with tropical plants in their mouths. Something caused it.