Why worry about it, polar shift is 250,000 years over due and when it happens thats the end of us all. Polar shift happens every 1/2 million years and its been close to 750,000 since the last one, all life ceases to exsist and the world gets covered in ice, no sunlight penitrates the dust cloud that covers the earth for hundreds of years. I don't sweat the global warming or CO 2 levels, its just sweating the small stuff

magnetic pole shift has NOTHING to do with temps
yes the poles do shift and a compass will point the wrong way
but the air and sea temps willnot change as a result

and all life has never died in any event

btw global warming is real but our star is quiet resently
there has been no sun spots for some time now
so the sun is now not quite as hot as normal

the sun will go back to normal in a year or three and
then the warming trends will resume

my understanding is that all the causes of variations in climate over the last 4 B years are not perfectly known

I have not seen magnetic pole shift offered as a cause tho. Last tome I read on this related continental drift as a likely major cause.

This is all over time spans of 10 to 500 million years of course, not the relatively short span of centuries that we see now.

re extinction - it is possible that all life on Earth was rendered extinct early on, but we have no way to determine that. There has not been a complete extinction within the last ~ 4 B years tho, we are certain of that. The ver worst extinction was caused by a mutation that unleashed a highly poisonous gas -- oxygen.

Of course, the life forms and their evolutionary progeny that survived LIKE oxygen... and they are the ones that get to write history.