Just read that B.P., aka Before Present and Before Physics, apparently is counted from 1950, before nuclear testing changed carbon dating. It's about as arbitrary as using the estimation of Jesus' birth, which is before major man-made explosions in general. It's also known as C.E., aka Common Era, Current Era and Christian Era.
B.P has its "zero" point set at 1950 for several good reasons having to do with nuclear testing and C14 dating. C.E. and B.C.E are still set to what we actually used as the zero point, where B.C.E (Before Current Epoch, or Before Current Era) has its zero at the birth of Christ, just like B.C. (Before Christ). They just changed the initials and definition to be politically correct.
In the words of one of my history professors, it was "total chickensh*t", and her having to explain it in every class is a "total pain in the a$$", and "an asinine waste of my lecture time".
If they were going to change the zero point for some valid scientific reason, and then rename it accordingly, fine, but just changing the name of it was, well, exactly what the good professor called it.
AUC is a good compromise.
No to be stupid, but why not just use the word "ago". As in, 15,000 years ago there was a nuclear explosion over Detroit.