What will happen if or when the direction of Earth's magnetic field reverses, so that compasses point south?
A simple question, but this is a hypothetical that could profound affect the planet. A magnetic reversal isn't instantaneous, but is a process that takes between 1,000 and 10,000 years to complete. That transition is what would be difficult to weather since a strong magnetic field helps protect Earth from solar radiation blast. The technology we depend on for communication would be in great jeopardy...the list of possible ramifications is extensive.