In my recent eco-novel A Diary in the Age of Water the limnologist Lynna makes the following entry in her diary in 2057:

Last night after supper, Hilde and I went for a walk along Shaw to Christie Pits, where I used to play as a kid. She wanted to show me the magnificent aurora borealis that had been streaming dramatically for the past several weeks. When I was a kid, auroras this far south were unheard of. Now they are common. The night sky was clear, and we enjoyed the fresh spring air as we ambled down Shaw Street. We parked ourselves on the damp grass among other spectators of the colourful night sky and watched the dancing light show.

It was mesmerizing: ribbons of mostly green and pink light rippled as if tugged by a mischievous wind. They danced with a kind of life that brought me back to my childhood. Northern lights happen when the magnetic field of our planet is disturbed by the solar wind. As the particles slide along the contours of the Earth’s magnetosphere, they glow as they lose their energy. The particles energize the air molecules enough to make them glow in various colours, depending on the composition of the gases.

Earth’s magnetic field is generated and maintained by an ocean of superheated, swirling metal around a solid iron core. These act like a dynamo to create electrical currents, which, in turn, create our magnetic field. But our magnetic field is weakening, and a flip is imminent. In the past two hundred years, the field has weakened by fifteen percent. That’s why we’re seeing these auroras in Toronto. A weaker field creates more auroras. They’ve become common here, particularly during the winter and spring months. Nasa predicts that the field could be gone in five hundred years or less and then take another two hundred years to rebuild. 

The field will first become more complex and might show more than two magnetic poles—playing havoc with our navigation systems and God knows what else—until it is entirely gone. Then it will presumably build and align in the opposite direction. When the magnetic field goes, so will our shield against radiation. First, the ozone layer—our shield against ultraviolet rays—will be stripped away, and then the atmosphere may lose other key elements and grow thinner. Will we end up like Mars 4.2 billion years ago, when severe solar storms stole its very atmosphere and evaporated all its water? 

Mars once had a strong magnetic field like Earth. But then Mars cooled and its conducting geodynamo stopped rotating. In the absence of the protective field, the solar wind surged in and excited the ions in the upper Martian atmosphere to an escape velocity. The solar wind just swept the air away. The surface pressure of the Martian atmosphere dwindled from one thousand millibars to six millibars. Mars lost about the same atmosphere that Earth has today. 

Mars is our destiny; it’s just a question of when. We’re all batteries, running dry. I considered this probable fate for Earth as we watched the exquisite example of our changing magnetic field. But I didn’t share it with Hilde, who watched with her mouth open in rapt wonder. If she’s lucky, she will experience no more of this progression than these amazing auroras. The weakening magnetic field and the associated loss of protection and atmosphere won’t happen for a while. I hope.
—A Diary in the Age of Water

In a 2019 article in New Atlas, David Szondy tells us that “North isn’t quite where it was after the Earth’s north geomagnetic pole made an unexpected sprint across arctic Canada.” Apparently the magnetic pole is moving faster than predicted. The shift is caused by a push/pull between two patches of magnetic field—one under Canada and another under Siberia. The Canadian one appears to be weakening…

Every few hundred thousand years our magnetic field reverses—with the magnetic north switching places with the magnetic south. The last major geomagnetic reversal occurred 780,000 years ago. Between the full geomagnetic reversals—which can last up to 10,000 years—shorter disruptions occur. These are called geomagnetic excursions and are short-lived, involving temporary changes to the magnetic field that last from a few hundred to a few thousand years. The most recent recorded geomagnetic excursion is called the Laschamps Excursion some 42,000 years ago.

“The Laschamps Excursion was the last time the magnetic poles flipped,” explains Chris Turney, one of the lead scientists of the Science study. “They swapped places for about 800 years before changing their minds and swapping back again.” Although scientists have known about these magnetic pole events, they have not clearly understood their impacts on life and the environment.

Then a study reported in the journal Science on a recent discovery in New Zealand of an ancient kauri tree, not only confirmed the time of the magnetic collapse, but shed some light on the dramatic period of environmental change, particularly in the time leading up to the few hundred years the Earth’s magnetic field was reversed. These included a depleted ozone layer, higher levels of ultraviolet radiation, and increased atmospheric ionization, all coalescing about 42,000 years ago in the Laschamps Excursion. “Early humans around the world would have seen amazing auroras, shimmering veils and sheets across the sky,” says Alan Cooper, one of the lead scientists. “It must have seemed like the end of days.”

The researchers also speculated that the magnetic field disruption led to an influx of cave art, driven by the need to seek shelter from the increase in ultraviolet rays—particularly during solar flares. The researchers also suggested that the event prompted the extinction of several megafauna in Australia and the end for Neanderthals—whose extinction occurred around 42,000 years ago.

Cooper points to the current movements of the north magnetic pole across the Northern Hemisphere as a potential warning sign of an impending event.

“This speed – alongside the weakening of Earth’s magnetic field by around nine per cent in the past 170 years – could indicate an upcoming reversal,” says Cooper. “If a similar event happened today, the consequences would be huge for modern society. Incoming cosmic radiation would destroy our electric power grids and satellite networks.”

Alan Cooper

Making Mars Inhabitable By Re-establishing its Magnetic Field

“Our quest on Mars has been to ‘follow the water’ in our search for life in the universe, and now we have convincing science that validates what we’ve long suspected,” said NASA’s John Grunsfeld.”This is a significant development, as it appears to confirm that water – albeit briny – is flowing today on the surface of Mars.”

That was step one. Mars was once just like Earth, with a thick atmosphere and flowing liquid water.

In a 2017 article in Science Alert, Peter Dockrill reported that “NASA wants to launch a giant magnetic field to make Mars habitable.” This bold plan was to give Mars its atmosphere back and make it habitable for future generations of human colonists consists of launching a giant magnetic shield into space to protect Mars from solar winds. With the shield in place, scientists argued that we could restore the atmosphere and terraform the Martian environment so that liquid water flows on the surface again. Mars once had a thick atmosphere like Earth currently has. 

In 2018 NASA concluded: “Our results suggest that there is not enough CO2 (carbon dioxide) remaining on Mars to provide significant greenhouse warming were the gas to be put into the atmosphere; in addition, most of the CO₂ gas is not accessible and could not be readily mobilized. As a result, terraforming Mars is not possible using present-day technology.”

Then in 2019, Harvard scientists proposed a way around the problem of insufficient CO₂ for greenhouse warming. They proposed that by “covering certain areas of the Martian surface with a thin layer of silica aerogel, namely areas with large amounts of water ice, enough sunlight will come through for warming and combine with natural heating processes beneath the surface to create a potentially habitable environment.”

The study demonstrated through experiments and modelling that under Martian environmental conditions, a 2–3 cm-thick layer of silica aerogel would simultaneously transmit sufficient visible light for photosynthesis, block hazardous ultraviolet radiation and raise temperatures underneath it permanently to above the melting point of water, without the need for any internal heat source. 

“Once temperatures were adequate, the gases released from the ice in the lakes and regolith (soil) would build up to form a pressurized atmosphere under the aerogel layer. If successful up to that point, microbes and plant life could theoretically survive. “Placing silica aerogel shields over sufficiently ice-rich regions of the Martian surface could therefore allow photosynthetic life to survive there with minimal subsequent intervention,” the scientists suggested. This photosynthetic life would go on to produce oxygen for pickier Earth dwellers to utilize,” reports Dacia J. Ferris of Teslarati.

p.s. I’m sure I’m not the only one who sees the irony of this situation: Mars has insufficient CO₂to warm its atmosphere, when Earth suffers from an excess of this greenhouse-warming gas. While going to Mars is one of my dreams (quite unrealizable for me; but I’m allowed to dream, no?), I still harbor an unsettling feeling that comes with the uncertainty about our prowess in this endeavor. We haven’t exactly been successful in controlling our own runaway global warming. Read Ray Bradbury’s Martian Chronicles to get my meaning.