Why is Carbon 14 Dating inaccurate?
At a simple level, carbon-14 dating might be based on an assumption that the rate of production of carbon-14 (due to cosmic rays hitting the upper atmosphere) has been fairly constant. It does vary to some extent. Some of the variation in recent centuries has been caused by burning fossil fuels and by above ground nuclear tests. It is possible to make adjustments for these factors.
Secondly we need to assess the half-life of carbon-14. There seem to be various estimates, around the
Thirdly, the actual proportion of carbon-14 to carbon-12 is rather small - on the order of
Radiocarbon dating is generally useful for dating organic items up to about