The sun follows an 11-year cycle that is currently building toward its "solar max," during which time the sun is more active. When solar storms occur, the sun can emit tides of electromagnetic radiation and coronal mass ejections, large bubbles of gas threaded with magnetic field lines. CMEs are essentially balls of plasma, and when they reach Earth, they release energy visible as colorful auroras. They may be pretty, but they unleash static discharges that can disrupt or knock out power grids. Solar flares, eruptions of supercharged protons, can reach Earth in minutes and also have catastrophic consequences.
NASA says modern power grids are so interconnected that a large sun storm could cause failures that would cut power to 130 million people in the U.S. alone. Outages would cost trillions of dollars and take years to fix, communications would be cut off, international trade might halt, and millions of people could die. Sound like science fiction? In 1859, a solar storm caused telegraph wires to short out in the U.S. and Europe, and in 1989, a solar storm knocked out power to all of Quebec, Canada. However, NASA predicts that the solar max that will occur in the 2012-2014 time frame will be average and says “there is no special risk associated with 2012.”