Question: Will we all fry like bacon when the magnetic poles flip? I do wonder. You might too (or not. And that’s okay too).
Here is what we do know. The Earth’s magnetic field has weakened by 40% since the 1650s and our magnetic north pole is on the lam; it moved 64 kilometers (about 40 miles) away from Canada and towards Russia in 2009. Clearly, something is underway. That something could be a complete pole reversal, an event which, strange as it sounds, is not uncommon. Or it might just be a “geomagnetic excursion,” which is exactly what it sounds like—the geomagnetic pole wanders off for a stint, like a dog taking itself for a walk around the block.
If a pole reversal is occurring, it will be a lengthy process, expected to last for one or two thousand years. During this time our magnetic field, which deflects cosmic radiation away from our planet, will be reduced to one tenth of its normal strength. So with that protective shield drastically weakened, what on Earth (pun intended) will happen?
“Life would go on,” says Phil McCausland, a geophysicist from McMaster University in Hamilton, Canada. “It won’t be catastrophic for civilization.” Life on earth has survived countless pole reversals in the past without a problem—they happen about four times every million years. Even without the magnetosphere, our lower atmosphere will effectively shield us from solar radiation.
Not everything will be normal, though. The navigational abilities of GPS, satellites, birds, butterflies, and countless other critters—all of which figure out where they’re going using the magnetic field—will likely run amok.
Lower orbiting satellites will most certainly be screwed in other ways, says Stefan Maus, a NOAA geomagneticist in Boulder, Colorado. These satellites, which include the International Space Station, most weather satellites, communications satellites and earth observing satellites, orbit the earth at altitudes between 300-1,000km and travel at about 8km/second.
“If you change the geometry of the earth’s magnetic field, it will change the currents which heat the atmosphere—and that means you will also change the air drag on the satellites,” explains Maus. Plus, without the magnetosphere around to deflect radiation, “the most dangerous thing for these satellites is high levels of radiation,” he says.
Things won’t be completely normal down here on Earth’s surface, either. For one thing, we’ll be privy to a rocking aurora show, says McCausland. Aurora borealis, also known as the northern lights, are usually sighted up near the north magnetic pole, where the magnetic field is weak. However during a pole reversal, when the magnetic field is weakened across the globe, aurora will be visible at most latitudes as charged particles hit the upper atmosphere. They’ll give us a light show as they dissipate their energy.
What about the weather? Recent studies have found links between the levels of cosmic radiation and cloud cover on Earth. Even though the observed effect is very small, during a pole reversal the increased amount of cosmic ray particles hitting our upper atmosphere could send our climate reeling in the lower atmosphere by nucleating clouds and changing weather patterns, wreaking even more climatic havoc than global warming is already causing, hypothesizes McCausland.
No one is exactly sure of how long all these changes will take to transpire. The widely accepted time frame is 1,000 to 2,000 years, but it could be quicker—much quicker. “There’s still an outside possibility that something could happen as quickly as 40 to 50 years,” says McCausland. “It’s unlikely, but it’s possible.“
Paper road atlas, anyone?