The problem with polar shifts
The problem with polar shifts is that they are so problematic. We can’t seem to get a solid definition of one (geologists have one, but the rest of us don’t understand enough of it). We don’t really know how it happens (although geomagnetologists have some theories). And we’re not sure when it will happen or when it happened before (everyone is arguing about this!) Another problem is that while we may remain blissfully unaware, there may be huge ramifications for the human race.
First, the general public thinks of polar shifts as the point at which magnetic north and south switch places. But geologists think of ‘polar shifts’ as the movement of the poles from one place to another. The North Pole stays in the same general area, but it moves hundreds of miles one way or the other. This happens all the time. Sometimes it’s slow, sometimes it’s fast, like now: magnetic north is nearly seven hundred miles from where it was thirty years ago. It is moving so fast today that the prevailing theory is that we are headed for a ‘Full Polar Reversal’, what most of us would call a ‘Polar Shift’. This is where the magnetic poles really trade places.
The problem with complete polar reversals is that no one really knows how they happen. As usual, there are a handful of theories to peruse. Some think that the poles slide around the surface of the earth, which is probably the easiest theory for laymen. Some say that they drift through the middle, thus leaving the Earth without a magnetic field, or at least confused, for an indeterminate period of time. Another theory, much more complicated, has “critical points”. In this case, the poles will start to slide, but in the next phase there will be places on earth that reverse their polarity before the poles switch places. These hotspots of reversed polarity (hotspots) will continue to form, and perhaps grow, until they reach a critical mass. This required number is unknown at this time. When the mass of the critical points is sufficient, the poles will instantly change places and everything will calm down. Only, at this point, your compass will point south instead of north.
All of these theories, as well as a few others, share one thing in common: they are backed by evidence and a good contingent of believers. This is a big problem. The scientific community is all over the map. If we look at other big controversial theories, we will find that the extinction of the dinosaurs is still being debated. In school, we are taught that an asteroid hit the earth and the resulting cloud of dust choked life on the planet. While many points on this are agreed upon, there are still many fields that debate the issue. Was the asteroid big enough to cause a global dust cloud? Is the Yucatan Crater Evidence of an Asteroid Big Enough? Alternatively, a series of volcanic eruptions could have caused such a cloud. Did? Were the volcanoes caused by an asteroid impact? There are strong believers on both sides of each of these questions.
To add to the arguments, geological strata don’t exactly come with an exact timestamp. There is still discussion about how often polar reversals occur and when was the last one. Some put the changes approximately every 600 to 800 thousand years. If these people are right, this is great news for the rest of us. It means that we humans have survived a reversal in geologically (and evolutionarily) recent time. This would indicate that we are in a good position to survive another. Other theories place the changes at intervals of about 5 million years. Not so good news. While there were humans on earth at the time, we were a different species then. Our ability to survive is questionable in this case. And the longest theoretical stretches put the polar exchanges at intervals of about 60 million years, with the last one occurring about 65 million years ago. This theory bodes ill for us on all fronts.
Humans didn’t live 65 million years ago, dinosaurs did. And they were about to go extinct. One of those debates about the extinction of the dinosaurs is whether the asteroid impact triggered a complete polar shift or if it just happened naturally at the time. Most geologists agree that the Earth’s magnetic field was probably much stronger back then, and this is what allowed the dinosaurs to reach their great size. And many believe that with polar reversals, the magnetic field changes strength, which is also bad news for species that have evolved to adapt to a particular field strength and direction.
There are additional problems with dinosaurs going extinct when other species did not. There are many theories floating around out there, but like the rest, there is still a lot of debate. Still some basic facts cause problems, the first of which is that the dust cloud choked off plant life, thus starving the dinosaurs. If dinosaurs were warm-blooded (another debate for another day), then they should have died at roughly the same rate as mammals, since they would have had similar functionality. However, if dinosaurs were cold-blooded, mammals should have died faster. Warm-blooded creatures require much larger amounts of food to operate from day to day. The mice, though small, will starve to death within days (losing all their energy to body heat and the like). An alligator, on the other hand, can easily go months without eating. It breathes slower and requires less input on all fronts because metabolism is much slower for cold-blooded creatures. There is another problem with the extreme cold caused by the dust layer: the theory is that only mammals could survive with their warm fur. But mammals are just as unlikely to survive that kind of climate change as any other kind of creature: each species is adapted to its environment (meaning even Canadian house cats will freeze in the arctic).
The final problem is that there is no real answer to the polar shift question. No one can prove how or when they occur, or what kind of damage they might do to life on the planet when they do. What many agree on is the fact that the poles slide quickly. And it looks like another change is upon us. There is no agreement on the time frame yet; for all we know, they could break tomorrow. But we don’t know what the change will do to us. Regardless of whether or not the last polar shift was involved in the death, or outright death, of the dinosaurs, any polar reversal doesn’t look good to us humans.
There are too many animals that depend on the magnetic field as it exists today. Every day we see migratory species use field lines to tell them where to go when they travel. So many birds migrate that a change in these patterns alone can, and probably will, cause global catastrophe. While many people don’t care when birds show up from season to season, we will care when we’re invaded by flies and mosquitoes or mice and rats carrying life-threatening diseases. Most of us can live without free-roaming rodents inside our homes, but your house will be just another place to set up camp when they get overcrowded. (We have already learned a lot about what it would mean to have pesticides in our homes to combat this problem.) Migratory aquatic mammals are another example that most of us never consider. Whales and dolphins also follow magnetic field lines, migrating thousands of miles annually, eating various species of fish and other marine life along the way. We also eat some of these species of fish, and if the whales stay in one place all year or migrate to some new route, there will be entire areas without a relevant food source.
Bees may be the biggest concern of all. Already dropping like flies (with no explanation on the horizon), bees as we know them could end up with a magnetic reversal. The findings show that scout bees locate pollen sources and return to the hive where they do a “bee dance,” explaining to other bees how to find the same field. This dance is very much rooted in the bees’ sense of magnetic field lines. If bees can’t find flowers, they can’t pollinate plants, like the ones we eat. The animals we consume also eat these plants. Some estimates indicate that eighty percent of our food sources have critically involved bee pollination. Plants may be at the bottom of the food chain, but bees are the next layer between us and our plants. As humans, we tend to get very attached to things like eating, and a magnetic reversal could spell the end of much of that.
None of this even considers the internal magnetism of humans. We don’t yet have the knowledge base to know how this will affect us. Most of what we know about human magnetism is that they exist, we just don’t know how they work or what they do for us. How important are our internal magnetisms? All we can see is this: Fifty years ago we would have completely ruled out the possibility that whales were magnetic, and today we know that many ecosystems rely heavily on migratory patterns, based on the internal compasses of whales.
It is quite possible that the Earth’s magnetic poles will shift tomorrow and no one will see any change, like the much-touted Y2K bug. But it seems more likely that a polar reversal will not go unnoticed. The poles are slipping right now, at an alarming rate. Geologists seem to agree that we are headed for another complete reversal, but they disagree on when that will happen. Every day we see headlines about unexplained bee deaths, dolphins stranded in increasing numbers over the last seven years, or bats in New York dying of some unknown process that cannot be identified as bacteria, viruses, or another recognizable ailment. A complete polar reversal is definitely a journey into the unknown, so batten down the hatches and grab your compasses. Change is coming.
