What if north was south?
Scientists researching Earth’s magnetic fields have noted for years that they are weakening and we are most likely moving towards a reversal of the poles – when the North Pole becomes oriented in the south, and vice versa.
Such reversals have occurred in the past, approximately every 450,000 odd years or so. It is important to keep in mind that 450,000 years is just an average, and the magnetic fields can remain stable for millions of years without shifting. However, given that it’s been almost 800,000 years since the last reversal, we’re more than overdo for another one.
Now, no one knows exactly what will happen in a reversal or how to predict when the next one will occur. It is, however, likely to be similar to a geomagnetic storm on steroids. Often caused by solar winds, these storms disrupt satellites, radar, and radio communication. They have also been known to disrupt electrical grids by producing induced currents that can greatly damage long transmission lines. The power systems of North America, China and Australia are particularly susceptible to these storms and it is possible that the damage could be severe enough for it to take weeks to recover from (or months if Pepco owns the grid…).
So even though no one knows what will happen in the next reversal, multiplying these effects to the “worst case scenario” gives us a good base case. However, the reversal isn’t a sudden process; we’re unlikely to wake up and find that the North Pole has shifted to Australia. Scientists have noted a gradual shift of the pole eastwards, which could potentially speed up as we journey through the transition period. This makes it unlikely to cause the apocalypse (although the risk still remains).
What’s more likely is an extremely strong geomagnetic storm caused by solar winds, or a geomagnetic excursion. The second of these is more frequent that full reversals and occur when the poles “wander” a bit due to a flex in the magnetic field. The magnetic field perceived at the level of the Earth’s surface becomes greatly weakened during these events. It is possible that the “transition” stage that scientists think we are currently in is simply one of these events. While mankind has survived at least one excursion event before, the effects on modern technology are unknown. It is very likely that the corresponding weakening or flux in magnetic would have more severe impacts than your standard solar storm.
Unfortunately there isn’t much you can do about these kinds of events, other than having the standard emergency preparations in place and being able to function off the grid for a while if necessary. Should the magnetic field weaken several and comic radiation starts to affect the planet, it’s unlikely we’ll have much to worry about at all.