Secrets of the Sun
Nova National Geographic
Explains, generally, how disturbances within and at the surface of the sun can dramatically effect the earth. Systems on earth that can be affected include communications and electrical power distribution. Those effects could be severe. In a worse case senario, continent size areas of earth could be without electrical power for years. A solar storm strong enough to cause such a disruption is predicted to occur at some time in the future.
Alan Detwiler, author of Thrivers In An Uncertain Future; bio at