“Because the geeks at NOAA say it’s in a decline based on their measurements. NASA is aware of, and adjusts for a particular spot east of South America.”
Earth’s MAGNETIC field always changes.
And the spot off South America is the SAA, it has to do with trapped solar particles.
Neither have anything to do with EMP caused by a nuke.
I'm not particularly worried about EMP from nukes. But our feral gooberment takes it seriously enough to spend billions of our tax dollars preparing for it.
/johnny