The BBC has an interesting article on the Earth's magnetic field, examining the fact that it is losing stability at a much faster rate than in the distant past.
The Earth's magnetic field protects us from dangerous solar radiation. In the past the magnetic field lost stability at a rate of 5% per century, but recent studies show that the field is now losing stability at a rate of 5% per decade.
If the magnetic fields were to flip compasses would point due South instead of due North. Recent studies indicate that the Earth's magnetic poles have flipped approximately 170 times in the last 100 million years. While pole reversals used to happen once every 5 million years, they now happen much more frequently: approximately once every 200,000 years.
So are we due for another flip? It's hard to say, but the magnetic field's increased rate of weakening has some speculating that a magnetic pole reversal is imminent.
Read the whole article here on the BBC website.