Wildcard—Massive Solar Storm: Threats to Power, Communications, and Navigation


THE WILDCARD: On September 1, 1859, astronomer Richard Carrington watched a massive solar flare erupt from the surface of the sun. The “Carrington event” sent a stream of charged particles toward Earth—producing the largest disturbances in Earth’s magnetic field ever recorded, lighting the night sky with beautiful auroras visible as far south as Cuba, and causing major telegraph outages.

The probability of an extreme solar-weather event as large as the Carrington event of 1859 occurring in the next decade has been estimated at about 12%.

The intensity of solar weather peaks on an eleven-year cycle, with the next expected peak in 2012–2015.

Measured elements of solar weather include solar flares, coronal mass ejections, solar wind, and solar energetic particles.

Solar flares emit streams of charged particles; when the particles reach Earth, they cause changes in the planet’s magnetic field and electrical environment that can, for instance, induce DC currents in power grids with the potential to disrupt and damage electrical systems.


  1. Solar weather has the potential to disrupt the electric grid, communications, satellites, and GPS systems.
  2. The probability of a solar megastorm is surprisingly high, forecast at 12% over the next decade.
  3. Such a storm could cause widespread, prolonged loss of electric power, interrupting transport, communications, and the provision of basic necessities.

Rising vulnerability

In a world now heavily dependent on electricity and electronic communications systems that are intricately interconnected and electronically controlled, a solar megastorm could be catastrophic.

“Auroras damage electrical power grids and may contribute to the erosion of oil and gas pipelines.”7 Solar disturbances can interfere with high frequency radio communications and GPS navigation systems. High frequency radio communications could be completely blacked out in polar

regions. Spacecraft can suffer temporary disruptions to operation as well as significant damage to electronic and optical systems.8

Aware of these issues, the US has created the Space Weather Prediction Center to provide early warning of disturbances, leveraging new sources of scientific data. Awareness of potential problems is rising among industries at risk, and changes to equipment and procedures are being undertaken in order to minimize the impact of space weather events. Nevertheless, risk of damage to electrical systems from a solar megastorm appears to be increasing.9


Forecasting the impact of a major space-weather event is difficult, requiring knowledge of the size and duration of the event; the primary, secondary, and further consequences of the event; the ability of the infrastructure to withstand the impact; risk management policies in place; and the response capabilities of affected organizations, including governments.

Moreover, as technology develops, the pattern of interdependencies among systems grows and changes.

According to the report from a 2008 workshop sponsored by the National Research Council, a rough estimate suggests that in the US alone a storm of the size of the Carrington event could cause $1 trillion to $2 trillion in damage in the first year, while full recovery could require four to 10 years.

To understand the impact of solar weather, it is necessary to consider both primary and secondary effects of solar disturbances.


Planning for a major solar-weather event is a work in progress. Actions on several fronts are needed to achieve even a modest level of preparedness. According to Mike Hapgood, head of the space environment group of the British research and technology agency RAL Space, writing in the journal Nature, “We need a much better understanding of the likelihood of space weather disruptions and their impacts, and we need to develop that knowledge quickly.”

  • Better prediction. Understanding of the physics of solar weather and the availability of better measurements are improving scientists’ ability to forecast solar storms. The US Space Weather Prediction Center currently can forecast the arrival of a strong geomagnetic storm 10 to 60 minutes in advance with roughly 50% accuracy. Unfortunately, such a warning provides little time for utilities, satellite operators, and others to respond.
  • Better organization, planning, and coordination. Government agencies need to be better prepared to lead preparation and response to a solar megastorm. A 2011 report prepared for the US Department of Homeland Security recommends, “Because present coordination between agencies dealing with space weather is far less than optimum, the entire effort should have someone in charge with authority to resolve inter-agency problems.”19 Improved international cooperation is also needed.20 As one expert noted, “To my mind, there are few emergencies today that require such a close cooperation across the Atlantic as that of the geomagnetic storm.”
  • Redundant systems. In some cases, it will be necessary to create or retain backup systems so that essential functionalities can be maintained in case of primary system failure. For example, as of 2008, FAA policy was to maintain legacy systems for air navigation as a backup to GPS-based systems.


  1. Even if the estimate of a 12% chance of a “Carrington event” in the next decade is high by a factor of ten, the probability is still great enough to merit inclusion in business risk strategies.
  2. Businesses should consider creating contingency plans for an extended failure of the electrical grid at key facilities. They should seek to understand primary, secondary, and tertiary impacts of such an event, as well as how operations for their customers and key partners would be impacted. Consumer- facing companies need to understand how daily life—and purchasing—would be altered by this kind of wildcard event.
  3. Governments at all levels should consider creating contingency plans for an extended failure of the electrical grid that is local or regional in scope. The plans should address emergency provision of basic necessities to the general population, and also meet the needs of special populations including infants and children, the elderly, and those requiring ongoing medical care at all levels.