The Carrington Event is the harbinger usually referenced when the threat of space weather is addressed. So I thought it'd be helpful to write a post explaining just what it was.
One of the scary things I learned in writing my thriller Patriarch Run is that our civilization has unwittingly evolved to become absolutely dependent on the power grid. It's not an exaggeration to say that if the grid went down today and didn't come back up again, most of us would die.
Wall Street Journal: "An electromagnetic pulse from a nuclear device or solar storm would be catastrophic, yet the U.S. remains unprepared."
If a Carrington-class or larger event were to hit, transformers would fail everywhere. Power at a global scale would be disrupted for weeks, months, possibly even longer.
A superflare, off-the-charts of our current space weather classification system, should occur about once every 800-5,000 years.