Science

polarity has not switched since humans have been on Earth and it is way past due to happen.

The movement of the Great South Atlantic Anomaly which covers a broad section of the South Atlantic and South America is drifting and could cause a polarity shift. There are ancient magnetic rocks in the oldest past of the world, South Africa, that are indicating the shift is nigh

https://svs.gsfc.nasa.gov/4840

https://strangesounds.org/2018/03/south-atlantic-anomaly-pole-shift-earth-magnetic-poles-may-be-getting-ready-to-flip.html

I can't find right now where I saw the report. It did say during a pole reversal oxygen levels will be lowered considerably.

https://www.nasa.gov/topics/earth/features/2012-poleReversal.html

https://www.sciencedirect.com/science/article/pii/S0012821X14001629