Dating stuff after WWII is iffy because of the effect of atmospheric nuclear tests.
This is evolutionary atheistic propaganda spread to conceal the TRUTH. The TRUTH is that the rise in C14 since WW2 is in fact evidence of the flood of sin throughout the world since that date. Witness the spread of communism in eastern Europe and Asia. Witness the spread of evolutionism across the world. Witness the baby boom and the sexual revolution.
The TRUTH of the increase in sin and the increase in C14 is evident to all except those who deliberately choose to ignore the facts and deny their godsense. And science proves it.