Radiocarbon dating

David Campbell (
Mon, 13 Jul 1998 16:26:29 -0400

>1. What is the trend of observed C14/C12 ratios during the last 50 to
>80 years? (i.e. is it increasing or decreasing)
>2. Is there proof that the C14/C12 ratio has ever, in history, been
>higher than it is today? (Published information indicates that C14/C12
>ratios fluctuate + or - 10 to 15% over time)

Atmospheric nuclear bomb tests greatly elevated the 14C levels, with a peak
in the early 1960's. The atmospheric test ban has decreased 14C levels to
much closer to their earlier values.