The Carrington event of 1859 was the most intense geomagnetic storm in recent history. It occurred a few months before the peak of the solar cycle and was triggered by a coronal mass ejection associated with a huge solar flare of energy around 5 x 10E25 J (c.f. 10E9 Mt nuclear detonation). If this space weather event occurred today it would cause catastrophic disruption to technological systems costing some trillions of dollars. There is accumulating evidence that many such events may have occurred in the past, and that larger events occur at other Sun-like stars. This has important consequences for our civilisation on Earth. Here we review current literature to provide insight on the likelihood of such events on Earth. The conclusion may be surprising!