Carbon dating unreliable
Marine records, such as corals, have been used to push farther back in time, but these are less robust because levels of carbon-14 in the atmosphere and the ocean are not identical and tend shift with changes in ocean circulation.
Bronk Ramsey’s team aimed to fill this gap by using sediment from bed of Lake Suigetsu, west of Tokyo.
The creation rate of C14 (and so the proportion in the atmosphere) depends on the suns activity - so a lot of dates which assumed a constant rate are known to be wrong.
We can now calibrate this out by looking at C14 in tree rings of a known age - but the charge of "C14 dates are wrong" is used by nutters (sorry creationists) either deliberately or in ignorance.
It's difficult to tell what is being asked here.
This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form.
As a rule, carbon dates are younger than calendar dates: a bone carbon-dated to 10,000 years is around 11,000 years old, and 20,000 carbon years roughly equates to 24,000 calendar years.
Carbon dating is used to work out the age of organic material — in effect, any living thing.For help clarifying this question so that it can be reopened, visit the help center.The main thing is that it's consistent with other forms of dating.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.
Various geologic, atmospheric and solar processes can influence atmospheric carbon-14 levels.