In 1859, a massive geomagnetic solar storm known as the Carrington Event caused extensive damage to telegraph systems and other nascent electrical devices worldwide. Telegraph lines sparked and telegraph operators could send and receive messages without the use of electric batteries. The Northern Lights lit up the sky in all of North America. Though not widely reported, on July 23, 2012 a massive cloud of solar material similar in magnitude to the Carrington storm erupted off the sun's surface, radiating out at 7.5 million miles per hour. Fortunately the impact of the solar storm missed Earth by nine days because of the Earth's orbit position.

One report estimates that a Carrington-level storm today could result in power outages affecting as many as 20–40 million Americans for a duration ranging from 16 days to two years at an economic cost of up to 2.5 trillion dollars. A research paper in Space Weather estimated the odds of a Carrington-level storm at about 12 percent over the next 10 years. Early warning of such a storm is possible since satellites can detect impending storms and have the potential to provide a minimum one-day warning before it hits Earth.

So what would happen if the lights went out in much of the United States because of such a cataclysmic event? One could anticipate serious disruption of electronic payments such as ACH, cards, and wire transfers in the affected areas and beyond. What would one do to facilitate commerce in such an emergency? Well, cash and, to a lesser degree, checks could come to the fore. Use of checks would be problematic given the electronification of checks, high risk of fraud, and overdrawn accounts if banking systems are not up and running. Cash would have fewer problems if it were on hand to distribute to the affected population. Perhaps cash accompanied by ration books could be used to mitigate hoarding.

For a low-probability extreme-impact event that results in cash becoming the only way, among existing payment instruments, for commerce to take place, what contingency plans are in place to ensure that consumers and businesses can obtain cash? Since the contingency systems we have in place to handle a future Hurricane Katrina or Hurricane Sandy are likely not sufficient for an extreme event of nationwide scale, some of the issues that need to be resolved include:

  • How does one ensure that sufficient cash is on hand during an emergency?
  • How is cash going to be distributed and accounted for along the supply chain with ATMs and bank offices and their core systems inoperable due to no electricity?

Addressing these questions and others involves a monumental effort, and I don't have a ready answer. Fortunately, cash solves the problem for small-scale, low-value payments during a long-term power outage. That is, during the immediate, in-person exchange, it is an instrument that doesn't require electricity, communication networks, or computers.

This and other major calamities have always made me concerned about the push in some quarters for a full transition to electronic payments at the expense of payments less reliant on electricity and our communication networks. As an engineer by training, it is in my nature to wonder what can go awry if failsafe systems aren't in place when the unexpected happens.

With the possibility of a catastrophic event in our lifetime, would you rather have cash in hand or a card/mobile app? As for me, I'm going to the bank to cash out my accounts and then on to the hardware store to buy a gas-powered electric generator. Just kidding, though I think serious consideration and appreciation is needed for the contingency aspects of cash when things invariably go awry.

Photo of Steven Cordray  By Steven Cordray, payments risk expert in the Retail  Payments Risk  Forum at the Atlanta Fed