Carbon dating accuracy called into question after major flaw discovery. When the plant or animal that consumed the foliage dies, it stops exchanging carbon with the environment and from there on in it is simply a case of measuring how much carbon 14 has been emitted, giving its age.

Why is carbon dating analysis not always accurate?

But scientists have long recognized that carbon dating is subject to error because of a variety of factors, including contamination by outside sources of carbon. Therefore they have sought ways to calibrate and correct the carbon dating method.