Earth's Magnetic Reversal Won't Kill You

“Hi James,

I appreciate your attempts to get people to think about science and
geophysics in particular; but, no offense, this question you pose is ridiculous.”

That’s what a well-established Earth and Planetary scientist told me when I asked him what I could do to prepare for Earth’s next Magnetic Reversal (i.e. magnetic north becomes magnetic south) as if it were daylights savings time. 

First, some context. According to some people’s interpretation of the Mayan calendar, the world will end on December 21, 2012, with just four shopping days left before Christmas. Some of those people think that the Doom includes an impossibly instant magnetic pole reversal which will add to the mayhem of said Doomsday. Also, Sony just made a big movie about the Doom.

Anyway, back to the scientist. He continued:

Too many people already are under the incorrect impression that a magnetic dipole reversal might start within their lifetimes.  If the paleomagnetic record and all the theoretical studies on this problem that have been done mean anything, the soonest a reversal may start would be a couple thousand years from now and it's more likely that it won't.

I then reached out to another scientist - John Connerney of the Planetary Magnetospheres Laboratory at NASA Goddard – to get his take.

First question: Should we be worried about the next Magnetic Reversal?

Hear answer to "Should We Worry?"

Connerney added:

a reversal takes thousands of years to happen. Way beyond an individual's lifespan, to say nothing of attention span.

Okay, I said. But when the next one occurs, will it hurt???

Hear answer to "Will It Hurt?"

Connerney followed up our discussion with the following email, which summed the whole thing up nicely, I thought:

-    There's no way to say if we're in a reversal or not; the Earth's
field fluctuates in magnitude and direction all the time. To think the
field will reverse in the next few thousand years, on the basis of the
decrease we see today, is like thinking you'll become weightless in two
years, because you lost 10 lbs last month.

 -  Because it is a diffusion problem, an instantaneous change deep
within the earth can not be felt at the surface right away; it takes
hundreds of years for the field to decay. Just like baking a potato in
the (conventional) oven - it takes an hour for the heat to diffuse
through the potato into the center. The Earth is a very, very big potato.

 - Last, but not least, life on earth has evolved over millions of
years, through lots of magnetic field reversals, so we're adapted to it
at the very least. The birds, bees, and sea turtles that use magnetic
fields to either navigate (sea turtles and pigeons) or collectively
build their hives (bees) - they all manage to get it done even when the
magnetic field is unavailable for that purpose.

In short, we're good.

Okay then. I'm officially not worried and I'll stop trying to prepare for something that may or may not happen to me thousands of years from now.