Are Solar Storms the Next Big Threat to Humanity?
The current cycle of solar storm activity is set to peak in 2025. Scientists disagree whether the end of days is upon us, or it’s all just a storm in a teacup.
In this article, we’re starring straight at the sun to ponder the threat of solar storms. The idea of a billion tonnes of superheated plasma ejected from the sun with the force of 20 nuclear bombs and hurtling towards Earth at 1.6 million kiliometres per hour is frankly pretty damn terrifying.
But whether this represents a clear and present danger to life on Earth or is all just a storm in a teacup is up for debate. We’ve tried to make sense of the science to paint you a picture of the best and worst case scenarios. Either way, you’ll probably need a stiff drink if you make it to the end of the article.
What is a solar storm?
It all starts with the sun. That glowing ball of light in the sky is actually a 4.5 billion-year-old yellow dwarf star in the centre of our solar system. And it’s huge and hot. The diameter of the sun is around 1.4 million kilometres, and its core heat tops 15 million °C.
The sun is also an incredibly active place. It is a ball of hydrogen and helium that’s held together by its own gravity. Nuclear reactions at the sun’s core create the heat and light we experience on Earth — about 150 million kilometres away.
Radiation carries this energy outward from the sun’s core where it bounces around the radiative zone for 170,000 years or so. The energy eventually makes it outward to the convection zone, where the temperature drops to a chilly 2 million °C. This forms bubbles of hot plasma that move up onto the sun’s surface.
This process can get pretty wild. Electromagnetic radiation eruptions in the sun’s atmosphere — known as solar flares — can be incredibly powerful. Solar scientists classify solar flares according to their strength, much like the Richter scale is used to classify earthquakes.
X-Class solar flares are the most powerful. These bad boys launch massive loops — many times the size of Earth — off the surface and into the sun’s magnetic fields. This process can create as much energy as 20 nuclear bombs.
So we’re talking about incredibly powerful forces here. Forces so powerful, in fact, that an X-Class solar flare can trigger a coronal mass ejection (CME). CMEs are long-lasting radiation storms that interact with surrounding solar winds. A CME can eject as much as one billion tons of plasma from the sun’s surface at speeds up to 1.6 million kilometres per hour.
This plasma — which is a cloud of superheated protons and electrons — can hitch a ride through space on a solar wind, and make the 150-million-kilometre journey to Earth in a few days.
While this sounds terrifying, CMEs are actually very common and rarely pose a threat to Earth. During active periods, CMEs occur several times a day. Even during inactive periods, a CME will usually show up once every five days.
And solar winds blow CMEs off the sun’s surface in all directions. So the chances of a CME catching a solar wind pointed directly at Earth are relatively low. But that doesn’t mean it has never happened. Or that it won’t happen again.
At least a few significant CMEs have hit Earth. Scientists believe a solar storm impacted Earth about 9,200 years ago, and it was powerful enough to leave permanent scars on deeply buried ice in Greenland and Antarctica.
Much closer to modern times, a CME slammed into Earth’s atmosphere in 1859. Known as the Carrington Event, it took out telegraph wires across the globe and ignited widespread fires. Some telegraph operators even reported receiving electric shocks from overloaded telegraph equipment.
In 1989, another CME caused a 12-hour electrical blackout across the entire province of Quebec in Canada. It also affected power grids throughout the US, caused short-wave radio interference, and sent several satellites tumbling out of control.
What would happen if a solar storm hit Earth today?
We almost found out in 2012. On 23 July that year, a huge blazing cloud of hot plasma erupted from the sun and caught a solar wind headed directly to Earth. Fortunately, the CME narrowly missed our blue planet. But it was too close for comfort, and it got scientists thinking about what would have happened if it had impacted Earth.
Scientists believe if the 2012 CME had impacted Earth, it would have caused three waves of damage. First, we’d have noticed radio blackouts and GPS navigation errors due to X-rays and ultraviolet radiation breaching the upper layers of our atmosphere.
Then the arrival of accelerated electrons and protons would have acted kind of like a massive electrical charge through our atmosphere. This would have fried satellites and sent some spiraling out of orbit.
But that would have been only the beginning. In the third phase, billions of tons of magnetised plasma would have caused widespread power blackouts, and even completely burnt out huge power transformers.
According to the National Academy of Sciences, a direct hit by a CME the size of the one that narrowly missed Earth in 2012 could cause more than $2 trillion worth of damage. That’s 20 times greater than the cost of damage caused by Hurricane Katrina.
So what are the consequences of this damage for our cities and towns? This, of course, depends on the severity of the CME, but an extreme solar storm could cause serious havoc.
With GPS navigation systems disabled, planes would be grounded and logistics systems would be offline. Radio and TV stations would be unable to broadcast. Cities and towns would be without power, sewerage plants would be inoperable, and digital payments would be defunct.
There would be no power to your home, your internet would be out, and your landline wouldn’t work. You’d be unable to fill your car with fuel; you’d have no access to cash via banks and ATMs; supermarkets would be without power and dealing with a massive collapse in the supply chain; and the greater economy would grind to a halt.
The cost on human health could be great too. Radiation from a severe solar storm could cause organ damage, radiation sickness and cancer. If the CME was large enough, it could essentially mimic the effects of radioactive fallout from the meltdown of a nuclear power station.
And if you want to step into the full nightmare scenario, a CME could even trigger a full-scale nuclear war. In 1967 a powerful solar flare jammed surveillance radars in Alaska, Greenland and the UK. This was at the height of the Cold War, and the US military thought the radar jam may have been signaling an imminent Soviet nuclear attack.
Nuclear-armed aircraft were authorised to mount a catastrophic response — until scientists intervened at the last moment with evidence of a solar flare as the radar-jamming culprit.
The US military de-escalated and nuclear war was prevented. But the situation is evidence of the widespread, unexpected and potentially catastrophic impact a severe CME could have on Earth.
Are we prepared for a solar storm?
It’s clear that there are various preparations in place to protect us from the fallout of an extreme CME, but there’s still much we need to learn about solar storms.
Remember the 1989 solar storm that took out power grids in Canada and the US? Well, that got engineers thinking. Since then, many utility suppliers have built safety measures into power grids that are designed to protect transformers from burning out due to power surges caused by solar storms. That should isolate power failures to relatively small parts of the grid, and protect against wide-spread transformer burnouts that take an extended period — potentially months — to fix.
Some governments are taking additional protective actions. The Department of Homeland Security in the US, for example, has implemented a Recovery Transformer program that aims to design and build temporary transformers that can be installed as a stop-gap in times of emergency. Some power suppliers are using Faraday cages to protect important equipment from solar-storm surges, and others are building battery banks that can pump stored energy into the grid when a transformer fails.
It’s more effective, however, to briefly shut down the grid before a solar storm hits. But, to do so, we need to improve how solar storms are forecast. Currently, researchers say the worst case scenario is a 12-hour window from when a solar storm is observed on the surface of the sun to the moment it impacts Earth.
However, scientists won’t know how severe a solar storm is and exactly where it will impact until it’s much closer to home. For this, the Discover satellite will give us only about 60 minutes’ warning. Whether that’s enough time to shut down power grids in affected areas remains to be seen.
A similar problem affects satellites too. Solar storms and other geomagnetic activity can drag satellites out of orbit and interfere with GPS signals. Modern satellites tend to shield critical electronics from damaging radiation, but — like the power grid — it would be more effective to temporarily shut down vulnerable satellite electronics to prevent damage as a solar storm passes.
So expanding that forecast window will be the most effective way to protect our power grids and GPS satellites.
The Parker Solar Probe is offering hope in this area. It was launched in 2018 and, in 2021, became the first spacecraft to enter the sun’s atmosphere. Data coming back from Parker — and a similar spacecraft known as Solar Orbiter — is helping scientists learn more about solar storms and how to forecast them with greater accuracy. It’s still very much a work in progress, but we’re not exactly flying blind when it comes to predicting major solar storm events.
Food for thought
So how likely is it that an extreme solar storm will impact Earth? Well, that really depends on who you ask.
According to physicist Pete Riley, the chances of a Carrington-class solar storm impacting Earth are higher than you might expect. His analysis concluded that there is a 12 percent chance of an extreme CME hitting Earth by 2024.
However, a different 2019 study argues the chance of a Carrington-class solar storm impacting Earth by 2029 is between just 0.46 percent and 1.88 percent.
And on the alarmist end of the scale, in 2015 the executive director of the Electromagnetic Pulse Task Force on National Homeland Security told the US Congress that prolonged damage to the power grid could cause widespread starvation, disease and societal collapse that could kill 90 percent of the US population.
What we do know for sure is that the sun completes a solar cycle every 11 years. Solar storm activity builds during these cycles. Solar Cycle 25 began in December 2019, and is predicted to experience its peak storm activity in July 2025.
So, if the numbers are accurate, we’re talking about a small chance of potentially mass devastation. Shutting down power grids before a CME strikes could prevent much of that damage, and scientists are working to extend forecast timelines to give power plants and other utilities more time to respond.
If protection measures are effective, a big CME could amount to not much more than a storm in a teacup. But a lot will depend on the human reaction. Even best case scenarios concede that a significant CME would likely take out communication and electricity grids for at least a short period.
That could result in panic on the ground that manifests in looting, rioting and violence as terrified citizens are cut off from news sources and transportation, and left to fend for themselves as governments work to restore communication and electricity grids.
With GPS systems and radio communications also potentially affected, police, military and other emergency services could be offline or at least temporarily unable to respond as normal to civil unrest and calls for assistance.
However, the chance of an extreme solar storm impacting in the next handful of years is small — somewhere between 0.46 percent and 12 percent depending on which modeling you believe. And if one does hit, the protections we already have in place could limit the damage to a few isolated power outages and temporary GPS disruptions.
But that’s a $2-trillion-dollar bet we really don’t want to make.
Are you worried about an extreme CME or is it all just a storm in a teacup?
Please leave your thoughts in the comments section. But let’s keep it classy. Disagreement is good. It’s how we learn and develop our ideas. Disrespect is not good. Name-calling, fake-news pedalling and passive-aggressive skullduggery of all kinds is the signature of a small mind. Be better than that.
As usual a fascinating, informative and terrifying read. Who needs horror movies when we have real life. The Painter.