Loss of GPS
My suspicion is that the EMP risk is heavily overstated and that most electronics on earth would survive. Some power grids might well have trouble for a while and it would be an important lesson learnt in a number of developed economies that their infrastructure may not be as stable as they think. We have historical precedent to go on for that.
I am willing to bet though, that if whatever-it-is fried the majority of the GPS satellite constellation, and that GPS then became unavailable, a whole lot of trouble might come up that we are poorly prepared for.
Most of the world's trade is carried in large ships. As far as I can tell, once-mandatory knowledge of how to navigate without GPS is no longer a requirement, nor a skill in evidence amongst the majority of crew, even if they could find the sextant and blow the dust off it. Being lost at sea is NOT a pleasant experience (and that I can attest to from first-hand knowledge). I'm practically certain that a substantial loss of GPS would be a very serious issue for the bulk of maritime activities.
Aircraft supposedly have backup for GPS navigation - I'd love to see the effects on the typical flight-deck though if you popped the fuses for them and told them they had lost the GPS and would have to live with whatever INS they have, plus dead-reckoning and direction-finding from beacons. There might be a lot of sorting out of sheep from goats all of a sudden.
The Royal Academy of Engineering has published a study (http://www.raeng.org.uk/news/publications/list/reports/Global_Navigation_Systems.pdf) which highlights some of society's dependencies on GPS not only for positioning but also for the provision of accurate time signals (which, for example, the Airwave comms system for fire, police and ambulance is now dependent on). It's likely that the loss of GPS will cause some substantial headaches for a while.
Who is willing to bet that any proper DR procedures are in place for this kind of thing and exercises carried out to see what the effect would be before the event actually happens?
Biting the hand that feeds IT
