Based on a variety of evidence, the last time the Earth's magnetic poles flipped was 750,000 years ago. Going off of this, many sources say we could face another flip at any point. Now, before you panic and begin blasting REM out of the nearest speakers, I just wanted to fill you in on what the process looks like.
The process is much longer than most people think when first visualizing it. It is actually a process which is estimated to take 1000-10000 years. To explain why, the main factor behind the Earth's magnetic field is believed to be the liquid iron part of the Earth's core. The alignment of iron and it's flow creates a magnetic field surrounding the Earth. As the iron won't all realign in a matter of days in the transition period, Earth's field appears to grow weaker as orientations move, then multiple different poles may form, until eventually the poles are reoriented and effectively flipped. Will this cause confusion for many electrical systems, animals, and humans? Yes. One of the biggest dangers, however, is the lack of a strong magnetic field protecting Earth from harmful solar flares, which could wipe out modern electrical systems as a whole. This is a very real fear, with a severe storm occurring in 1859 known as the Carrington Event. This storm, even with a fully functioning magnetic field, managed to destroy large amounts of telegraph communications and caused auroras so strong they were seen in the Caribbean. While strong storms like this are rare, weak ones are fairly frequent. So, if the poles were to weaken, even the effects of a weak storm would be very destructive. Humanity would certainly not be the same after a direct hit.
Anyways, don’t panic, much of this is out of anyone's control anyways, besides, even with this threat looming over our heads, we continue to make scientific progress without hesitation, and, like any other hardship, we keep our heads up and move forward. So, to sum it up, the poles won't just flip one morning and be switched the next, it is a process which takes numerous lifetimes.
As always thanks for reading! - ThePeculiarParticle