Various geologic, atmospheric and solar processes can influence atmospheric carbon-14 levels.
Since the 1960s, scientists have started accounting for the variations by calibrating the clock against the known ages of tree rings.
What would happen if a dinosaur bone were carbon dated?
Y., reported today in the British journal Nature that some estimates of age based on carbon analyses were wrong by as much as 3,500 years. Climate records from a Japanese lake are set to improve the accuracy of the dating technique, which could help to shed light on archaeological mysteries such as why Neanderthals became extinct.Carbon dating is used to work out the age of organic material — in effect, any living thing.By measuring the ratio of the radio isotope to non-radioactive carbon, the amount of carbon-14 decay can be worked out, thereby giving an age for the specimen in question.But that assumes that the amount of carbon-14 in the atmosphere was constant — any variation would speed up or slow down the clock.