Welcome to Wikipedia, and thank you for your contributions. Although everyone is welcome to contribute constructively to the encyclopedia, please note that there is a Manual of Style that should be followed to maintain a consistent, encyclopedic appearance. Deviating from this style, as you did in Radiocarbon dating, disturbs uniformity among articles and may cause readability or accessibility problems. Please take a look at the welcome page to learn more about contributing to this encyclopedia. Thank you. BP is not the same as BC at all. Please read WP:ERA: In scientific and academic contexts, BP (before present) is often used. This is calibrated from January 1, 1950 - so changing it to BC is wrong by about 1950 years...
More generally, the policy on use of BC, BCE, BP etc is explained on that link too, in summary: Do not change the established era style in an article unless there are reasons specific to its content. Seek consensus on the talk page before making the change'' Babakathy (talk) 16:39, 22 November 2013 (UTC)