While lots of people are worried about the possibility of doom and gloom from global warming, there are other, more likely things to worry about. 150 years ago the sun sent a solar storm our way that resulted in visible auroras as far south as Havana. It also generated enough current in telegraph lines that the operators disconnected the batteries and ran them on the electricity in the air. It was, based on readings of ice cores, twice as big as any other solar storm in the last 500 years. Today it would wreak havoc with electrical transmission and could disrupt the world for years.