In 2012, Whitley Strieber released an ebook titled Solar Flares: What You Need to Know, that explained the potentially disastrous effects on our civilization that a large-scale coronal mass ejection, or solar flare, could have. In 1859 a large flare resulted in the Earth being hit by a massive geomagnetic storm, dubbed the Carrington Event. The storm was strong enough to knock out telegraph systems in Europe and North America, and would have had far more dire repercussions if it were to occur today, in our more electronically-dependent civilization.
But a new study has applied a phenomenon seen in other stars, known as superflares, to our own Sun. These superflares are estimated to be 10,000 times more powerful than the one that precipitated the Carrington Event, and could not only destroy our electrical grid and knock out satellite communications, but could also cause damage to the Earth’s atmosphere itself. A small-scale eruption like this appears to have occurred in 775 AD, as evidenced in the growth rings of trees found in Japan. This event was only somewhere between 10 to 100 times that of the Carrington Event — still a far cry from superflares in other star systems, but it would be devastating to our civilization’s electrical infrastructure.
Thankfully, the study shows that our Sun is extremely unlikely to produce a flare of that magnitude: while the underlying mechanism that generates superflares appears to be the same as what produces CMEs, these superflares tend to be generated from stars that have magnetic fields much stronger than the Sun, and many seem to be triggered by features that are not present in our solar system, such as binary stars that can generate a massive solar prominence between themselves. We would also have ample warning if a CME of that magnitude were to build up, as the sunspot that such an eruption would burst from would cover roughly 30 percent of the sun’s radius.