One of the modern threats to our civalisation. A plasma burst from the sun can reach earth with devastatinbg consequences for our modern age. These plasma flares had little impact on our grand parents because the impact is through electrical phenomenon. The flares create very large electrical currents and induce magnetic fields that reach the earths surface. If a long conductor is exposed to the magnetic fields then massive currents can be driven in these conductors. The US national grid is a prime candidate and the currents induced can damage transformers and other electrical infrastructure. It would take many years to replace the damaged infrastructure. A year long blackout is something that we cannot imagine in our modern society.
Plasma modelling of the sun can help us understand the phenomonem better. Plasma modelling of the sun may shed light on predicting sunspot cycles which affect GPS, Grids, Planes, http://bit.ly/GWP8HN