It can take a long time to clean up from natural disasters. New Orleans still had remnants of Katrina damage years after the storm barreled through. Hundreds of thousands of people are still homeless in Haiti, more than a year and a half after its earthquake. Areas of Japan may be off limits for years due to the earthquake/tsunami/nuclear disaster at Fukushima.

But as bad as these events might be, they are at least limited geographically. But that probably won’t be true when it comes to a severe solar storm, say scientists in a new study in Space Weather. Before I go into that, though, let’s first review what I mean by solar storms. These are explosions on the Sun that send energized particles out into space. If Earth is in the way of a mild outburst, we get pretty auroras at the poles. But more violent events can have bigger impacts, as Robert Irion noted earlier this year in his Smithsonian story “Something New Under the Sun“:

The most intense solar storm ever recorded struck in the summer of 1859. British astronomer Richard Carrington observed a giant network of sunspots on September 1, followed by the most intense flare ever reported. Within 18 hours, Earth was under magnetic siege. Dazzling northern lights glowed as far south as the Caribbean Sea and Mexico, and sparking wires shut down telegraph networks—the Internet of the day—across Europe and North America.

A magnetic storm in 1921 knocked out the signaling system for New York City’s rail lines. A solar storm in March 1989 crippled the power grid in Quebec, depriving millions of customers of electricity for nine hours. And in 2003, a series of storms caused blackouts in Sweden, destroyed a $640 million Japanese science satellite and forced airlines to divert flights away from the North Pole at a cost of $10,000 to $100,000 each.

Our modern, globally connected electronic society is now so reliant on far-flung transformers and swarms of satellites that a major blast from the Sun could bring much of it down. According to a 2008 report from the National Research Council, a solar storm the size of the 1859 or 1921 events could zap satellites, disable communication networks and GPS systems and fry power grids at a cost of $1 trillion or more.

These storms are getting more attention in recent months because the Sun has left its solar minimum—its time of least activity—and there are still three to five years until it reaches solar maximum. And although a host of satellites are now watching the Sun, leading to new insight into its activity and, eventually, better warnings of devastating storms, our technological society is still disturbingly vulnerable.

Back to the Space Weather study: Researchers from UCLA and elsewhere used simulations of solar storms to examine what would happen to the Earth’s inner radiation belt, a region of charged particles that surrounds the planet and acts as a buffer against radiation. They found that a storm the intensity of the 2003 event would halve the thickness of the radiation belt and one the size of the 1859 event would nearly wipe it out. And that would just be the beginning of the problem, New Scientist explains:

In the absence of the cloud, electromagnetic waves large numbers of electrons to high speed in Earth’s inner radiation belt, causing a huge increase in radiation there. The inner radiation belt is densest at about 3000 kilometres above Earth’s equator, which is higher than low-Earth orbit. But the belt hugs Earth more tightly above high latitude regions, overlapping with satellites in low-Earth orbit.

Speeding electrons cause electric charge to accumulate on satellite electronics, prompting sparks and damage. Increasing the number of speeding electrons would drastically shorten the lifetime of a typical satellite, the team calculates.

The satellite-damaging radiation could hang around for a decade, the scientists say. In addition, the radiation could also be hazardous for astronauts and equipment on the International Space Station.