Every two hundred thousand years or so the magnetic poles flip. Obviously it is not life ending but how would our weather change? How long does the transition take? Is there a map or model to show where the warmer areas would be effected from the loss of the mesosphere during transition?
Magnetic reversals are very random and unpredictable,but average about one every 260,000 years. We could have the next at any time,but as I say, they are unpredictable. So faras is known,they don't affect the weather,but they are very useful to geologists because they make tiny magnetic crystals in solidifying volcanic rock line up with the Earth's magnetic field. Thus,millions of years later, geologists can tell how the rock was lined up with the field when it was formed and can see for themselves how the alignment has changed in the intervening timespan. That gives them an insight into continental drift and other crustal movements. It is particularly useful in the study of sea floor spreading.