Massive Solar Flare

Few natural calamities have the same level of devastating potential to harm society as a solar flare. It won't destroy structures the way an earthquake or a tsunami would, and it won't kill people the way a supervolcano or meteor would. Instead, it may effectively destroy the world's electronic infrastructure, which would ruin our entire way of life. Trillions of dollars are thought to be involved in the cost estimate. Later, when all the other infrastructure failed, the deaths would occur. transportation, food, medicine, and communication. The domino effect would occur, and recovery would be exceedingly difficult.

In 1859, a solar flare illuminated the sky. A magnetic storm that followed produced aurora effects that were so bright you could read by them all over the earth. Even when they were unplugged, telegraph lines developed electrical charges that occasionally caused fires. And today, that would be the main issue. In 1859, technology was hardly developed. Imagine the world of today's electrical grid being magnetically supercharged.

The electrical grid would be turned off. That implies that global finance and communication have disappeared. And fixing it can take weeks or even months. Other catastrophes at least completely destroy everything. A geomagnetic storm and solar flare would only take us back in time.