Ask anyone to make a list of the worst natural disasters, and you’re likely to get a dissertation on the relative risks of hurricanes, floods, tornadoes, and similar terrestrial events. A solar storm, in contrast, is unlikely to make anyone’s Top 5. According to Joseph N. Pelton, the former dean of the International Space University, that’s a critical error in thinking that we need to address.
Pelton, who also serves as a board member of the International Association of Space Safety (IAASS), argues that humanity should create an artificial Van Allen belt to supplement the natural Van Allen belts that already exist around Earth. These belts extend from an altitude of 600 to 36,000 miles above the Earth’s surface and form a natural shield that prevents high-energy particles from hitting the Earth’s atmosphere.
Ordinarily, the Earth’s magnetosphere shapes the Van Allen Belts and deflects the charged particles emitted by the sun (called the solar wind), while the VABs act to block high-energy electrons. Periodically, however, the sun releases solar flares. These flares are high-energy events that release a concentrated burst of energy in a particular direction. If that direction happens to be towards us, it can temporarily compress the magnetic field and allow high-energy particles through the Van Allen Belts. The largest flares are sometimes accompanied by a coronal mass ejection — and as Pelton notes, these have the potential to wreak serious damage on both satellites and Earth infrastructure.
There’s certainly reason for concern. On September 1, 1859, the most powerful geomagnetic storm of modern times hit the Earth. Aurorae, normally visible only at high latitudes, reached the Caribbean. The glow over the Rocky Mountains was so bright, gold miners reportedly exited their tents and began preparing breakfast. Telegraphs failed across the world — though in some areas, they continued to send and receive messages, even after being disconnected from their electrical supplies.
The event became known as the Carrington Event, after British astronomer Richard Carrington — but what caused small problems and unusual events in the 1800s would be absolutely devastating today. The handful of moderate geomagnetic storms in the last 40 years have caused significant damage to the grid; a full hammerblow would destroy the US electrical grid for several years. The economic impact of a similar disaster today is estimated at $2.6 trillion.
Often, when online publications write disaster-themed science stories, there are a number of comforting facts buried below the lede to take the edge off. Sure, a dinosaur-level extinction event could make for a really rocky millennium or two on Earth, but the chances of a rock that big hitting the planet are minuscule. Reading up on the potential impact [PDF] a coronal mass ejection (CME) could have on Earth offers no such comfort.
The truth is, solar flares as large as the one that caused the 1859 Carrington Event happen fairly regularly. Since we started monitoring the Sun’s solar cycle, we’ve gotten lucky on a number of occasions — CMEs that would have hit us even harder than 1859 have merely glanced us due to a non-ideal trajectory. Meanwhile, the United States’ grid is more vulnerable to such events than ever before — our transformer grid is, on average, nearly 40 years old, high-voltage power lines are carrying far more energy than they used to on a day-to-day basis, and there’s virtually no way to quickly repair the damage such a storm would cause.
Just how much of a threat is this? We consulted the Department of Energy’s own research to get a better idea. According to that report, transformers are custom-designed, highly intricate, take up to two years to manufacture, cost between $5-7 million apiece, and weigh between 100 and 400 tons. Ordinary transformers are far too bulky and heavy to ship by road, and must be moved around the country in specially-designed railcars. Smaller models are available, but are typically more expensive.
The United States power grid is utterly incapable of weathering a devastating geomagnetic storm. In worst-case scenarios, the sheer amount of energy flowing down the high-voltage wire would blow transformers in quick succession. The automatic load balancing and considerable safety margins that are built into plants are designed to deal with terrestrial disasters, not space invasions. Offline power capacity normally used for supplementing baseline power during peak hours might survive, but these plants are not staffed or fueled for long duration. Up to 92% of the Northeast’s power generation capability could be taken offline for periods of several years.
A cascade failure that took out such a huge swath of our power generation would have untold downstream effects, as people lost the ability to contact emergency services, lost water pressure in areas that rely on electrical pumps, and were forced to rely on limited generator power. The damage estimates aren’t just theoretical — we know the electrical grid is sensitive to such geomagnetic storms after a surge in 1989 caused a major failure of a hydroelectric generator in Quebec. In the wake of that event, some of the US-based power companies instituted safeguards, but they’re woefully lacking compared to what could hit us.
Even moderate geomagnetic storms cause significant damage or accelerate failures in equipment. Two years after the 1989 storm, 12 mid-sized transformers had failed — all of them significantly earlier than had otherwise been expected. During solar storms on April 3-5 1994, major transformers failed in Illinois at the Zion Nuclear plant as well as facilities in Braidwood and at the Powerton coal plant.
The good news is, there are ways to protect the grid and mitigate the damage that another Carrington event would cause. The bad news is, we’re mostly not doing them, despite the catastrophic damage such an event will cause. The Washington DC/New York City corridor is considered to be most at-risk, with 20-40 million people in danger. It would cost several billion dollars to protect existing lines, far less than the $2.6 trillion quoted above from an actual impact.
Unlike dinosaur-level extinction events, geomagnetic storms that cause enormous disruptions in the Earth’s magnetic field are a regular phenomenon and were reported widely in historical journals and writings, stretching back to the dawn of human history. Storms with the power of the 1859 CME hit, on average, every 154 years.
With all that said, Pelton’s proposal to build an artificial VAB and link it to beaming solar power is probably unworkable with present technology. Space-based solar is an exciting concept with limited applicability given the expense of launching solar panels, the relatively quick degradation of said panels (panels in space break down about 8x more quickly than the same panels on Earth), the real risk of space debris destroying an orbiting array, and the cost of the receiving station on the ground. Then there’s the intrinsic energy loss of gathering energy in space, converting it to microwaves for transmission, beaming it back to the ground, and then converting it back into electricity.
Regardless of the feasibility of his proposed solution, Pelton isn’t wrong about the problem. The internet, like most of the rest of the United States critical infrastructure, is not defended properly against geomagnetic storms. A second Carrington event could destroy critical hardware that would take us years to fix.
Now read: How do solar cells work?