Perhaps the most devastating thing that could happen in any developed country would be widespread catastrophic damage to its electric power grid. Nearly everything in an industrialized nation relies on electricity to function. Without it, normal water supplies, sewer systems, and communication services are cut off. Furthermore, things like food and transportation are quickly affected when power is down for extended periods.

A severe electromagnetic pulse (EMP) or geomagnetic disturbance (GMD) event could take the power grid down for months, and possibly even for years. An EMP is a very intense pulse of electromagnetic energy, typically caused by the detonation of a nuclear bomb or other high-energy explosive device. A GMD, meanwhile, can be caused when a solar eruption produces a coronal mass ejection (CME) that travels from the sun to the Earth. A direct hit by an extreme CME would cause widespread power blackouts disabling everything that uses electricity. Some experts have suggested that a major EMP or GMD hit could result in the death of up to 90% of the U.S. population.

What makes the event so devastating is that the U.S. power grid is not well-protected from such a strike, and the country is not prepared to recover quickly. Dr. William R. Forstchen, author of more than 40 books including the groundbreaking novel One Second After, which has been credited with raising national awareness to the potential threat posed by an EMP strike, explained the situation as a guest on The POWER Podcast. He said an EMP is generated by lofting a small nuclear warhead of about 40 to 60 kilotons—roughly four times the size of the bomb used on Hiroshima in World War II—above the Earth’s atmosphere. When the bomb explodes, it causes an electrostatic discharge at the higher end of the atmosphere, called the Compton effect. “That static discharge then starts cascading down to the Earth’s surface almost at the speed of light. When it hits the surface, the electrostatic discharge feeds into all the wiring—all those wires are actually antennas as well—and within a second, it starts shorting out the electrical grid in the United States. Worst-case scenario: you take three of these weapons, one on the eastern United States, one in the central, one in the western, it would actually short out the power grid of the United States. One second after, we’re in the dark. We could be in the dark for months, perhaps even years,” said Forstchen.

While some might argue that no U.S. adversary would ever attempt such an attack out of fear of retaliation, the fact is, protecting the grid from such an attack would also help mitigate the effects of a GMD, which experts say is not a question of “if,” but rather, “when” one will occur. The impacts from most CMEs are minor—they can cause the well-known aurora borealis/aurora australis effects in the upper atmosphere—but massive CMEs are the real concern, and they have struck Earth in the past.

The most severe CME on record is known as the Carrington event, which occurred in 1859. That event caused widespread damage to the national telegraph system, in some cases starting fires and delivering electric shocks to telegraph operators. A CME in 1989 that was far smaller than the Carrington event tripped Hydro-Québec’s La Grande high-voltage transmission network, and caused widespread power outages and damage up and down the U.S. East Coast.

The risk of another Carrington-class CME striking the Earth is not clear, though it is thought to be about once every 100 to 200 years. A CME of at least that magnitude was observed in 2012, but it missed striking the Earth by about nine days because the solar flare was oriented in a different direction. Forstchen noted that the U.S. power grid is vulnerable to such an event for a number of reasons. “The average component in our electrical grid is 40 to 50 years old. We are running our electricity on a 1970s, early-1980s industry. We’re not modernizing it,” he said.

A few years ago, the federal government began to address the problem. “The Trump administration finally started taking action about six months before the election in 2020. They mandated DOD [the Department of Defense], DOE [the Department of Energy], all the different agencies to submit a comprehensive analysis of what needs to be done that would then follow by legislative action in the next Congress,” Forstchen explained. However, when Trump lost the election, President Biden immediately killed the initiative, he said.

Forstchen said relatively minor investments could vastly improve the situation. He suggested stockpiling key components is an important first step. “A large transformer for a major substation can cost several million dollars. From the time of ordering one until the big truck pulls up and we start to unload it is two or more years,” Forstchen said. Furthermore, he noted that most of the equipment and components that might be needed to repair the grid are now sourced from other countries, mainly China, which means the U.S. may not be able to get supplies, especially if the attack was initiated by one of those countries. “We should be building a strategic reserve of key electrical components,” he said.

Additionally, Forstchen said the U.S. should focus on a “lifeline to recovery.” He suggested hardening 10% of the grid could act as an insurance policy for the nation. “Let’s say the rest goes down, but we have those lifelines out there that can be used to start repairing things, bringing supplies, and communicate—big thing, communication and transportation,” said Forstchen. Risks could be substantially reduced with relatively minor investments. “I argue $20 to $30 billion a year would at least start ensuring some responsible response to this problem,” Forstchen said.

To hear the full interview with Forstchen, which includes more on the effects of a debilitated grid, what individuals can do to protect themselves, what companies are actually taking the initiative and acting on their own, among other things, listen to The POWER Podcast. Click on the SoundCloud player below to listen in your browser now or use the following links to reach the show page on your favorite podcast platform:

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Aaron Larson is POWER’s executive editor (@AaronL_Power, @POWERmagazine).