I have discussed in various articles over the years the threat of EMP - electromagnetic pulse events – from either high altitude nuclear explosions, or via the sun. There was nearly a catastrophe that would have dragged modern civilisation down the drain in 2012, but fortunately we lucked out, and the super-high energy zap from the sun only fried one unlucky satellite. Society is not prepared for a Carrington Event EMP, the name given to the largest solar storm which hit the Earth in 1859, roasting the telegraph system of the day:
https://www.naturalnews.com/2018-07-22-9-mind-blowing-effects-of-a-grid-down-emp-scenario.html
http://empcommission.org/docs/A2473-EMP_Commission-7MB.pdf
https://news.nationalgeographic.com/news/2011/03/110302-solar-flares-sun-storms-earth-danger-carrington-event-science/
https://www.businessinsider.com.au/massive-1859-solar-storm-telegraph-scientists-2016-9?r=US&IR=T
Even mainstream sources admit that modern electro-IT civilisation would be devastated. However, the effects are seldom detailed but the natural News.com article goes into some depth about what we could expect:
