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Today, September 10, 2021, Smart News offered an article pointing to a serious paper at the University of California, Irvine by Sangeetha Abdu Jyothi, “Solar Superstorms: Planning for an Internet Apocalypse”, 13 pages, PDF link here.
The paper considers the idea that a solar superstorm with a corona mass ejection arrival at Earth (13-hours-72 hours) could leave much of the power grid intact (more or less), but still destroy a lot of Internet connectivity, especially among countries, and especially affecting oceanic cables. It would take months to repair.
It also notes that the most serious such incidents in the world occurred in 1859 (Carringon), 1921 (before much of the world was electrified), 1989 (in Quebec, a smaller event), and a narrow miss in July 2012. CME damage normally happens only after pretty much a direct hit on Earth in its orbit around the Sun, considering the Sun in three dimensions.
The probability of a significant event in any decade can be as high as maybe 12%. We'll see sunspot activity increase from a min this decade.
Here is an introductory article in Livescience.