EMP threatElectromagnetic disaster could cost trillions and affect millions. We need to be prepared

By Anders Sandberg

Published 12 August 2014

In 1962, a high-altitude Pacific nuclear test caused electrical damage 1,400 km away in Hawaii. A powerful electromagnetic pulse (EMP) – created either by a solar storm or a high-altitude nuclear explosion — poses a threat to regions dependent on electricity, as such pulses could cause outages lasting from two weeks to two years. The main problem is the availability of spare transformers. Superstorm Sandy’s worst effects were in a single location. In the case of a big EMP surge, replacement transformers would be needed in hundreds of locations at the same time. The cost of an EMP pulse to the U.S. economy would likely be in the range of $500 million to $2.6 trillion. A report by the U.S. National Academies was even more pessimistic, guessing at a higher range and a multi-year recovery. Besides disrupting electricity such storms can also destroy satellites, disrupt GPS navigation, and make other parts of the infrastructure fail.

Predicting or worrying about disasters is a popular pastime. But we tend to take notice when somebody with money at stake becomes concerned. Financial people likely sat up when Paul Singer, manager of the Elliott Management hedge fund, warned in his latest newsletter that:

Even horrendous nuclear war, except in its most extreme form, can be a relatively localized issue, and the threat from asteroids can possibly be mitigated. The risks associated with an electromagnetic pulse, or EMP, represent another story entirely.

How right is he to worry about this?

A force of nature
Electricity and magnetism are tightly linked. Change an electric field — for example by moving charge — and a magnetic field appears. Change a magnetic field — for example by rotating a magnet — and electric fields appear. This is why electromagnets, generators and antennas work. Electromagnetic waves, whether radio, light or X-rays, are just oscillating fields.

The Earth has a vast natural magnetic field, courtesy of currents inside its core. As long as it is stable it is not noticeable except for turning compass needles. But what if something forced it to move? The change would produce currents in long conductors such as power lines or telecoms cables. The field is weak, but a shift across kilometers of cable can induce powerful currents, strong enough to burn out fuses or damage transformers and other electronics.

A sharper push — such as generated by a nuclear explosion — can produce currents that disrupt smaller devices. In fact, microchips are easily burned out by a few volts in the wrong place.

What worries Singer is either naturally occurring geomagnetic storms, caused by the solar wind interacting with the Earth’s magnetic field, or deliberately produced electromagnetic pulses (EMPs) by nuclear weapons, or so-called e-weapons, devices that have been developed to disrupt enemy electronics. If something causes widespread and persistent black-outs and equipment damage the economic damage — and human problems — would be enormous.

Stormy sunlit days
Could something like this happen? In 1859 a solar storm, the “Carrington event,” named after an amateur astronomer, caused auroras down to the Caribbean, making telegraph systems across the world fail — pylons threw sparks and operators got electric shocks. It is worth noting that telegraphs are simple, sturdy systems compared to today’s fine electronics.