From the interwebs.
Black Sky Event is one of a number of natural or man-made events that cause widespread, long-term power outages. Many of these are taken from history, and others are realistic potentials. A Black Sky Event in the 1800s or even much of the early 1900s would not have been much of a life-changing event. Starting around WWII and up to today, the need for power to run and manage our complex society has increased exponentially. Most of our processes in society are now electric power dependent. Loss of power means loss of communications now or soon. It means cascading consequences in communities and the supply chain. Transportation, water, and wastewater systems require power to function, as do retail of most types. A weeklong loss of power in a region will also cost lives, hospitals, homes, and elsewhere. A one-month regional power loss will have many long-term impacts