Carbon dating had never been, and likely never again will be, quite so glamorous — or so controversial.And, thanks to atmospheric changes caused by the burning of fossil fuels, it could become even more complicated.In 1988, thanks to a technique called radiocarbon dating, they had an answer: The shroud dated back to sometime between 12 — old, but not old enough to have been buried with Jesus.“The Carbon-14 Bombshell,” National Geographic called the news, referring to the radioactive isotope that’s used for the dating process.Thanks to fossil fuel emissions, though, the method used to date these famous artifacts may be in for a change.The burning of fossil fuels is altering the ratio of carbon in the atmosphere, which may cause objects tested in the coming decades to seem hundreds or thousands of years older than they actually are, according a study published in the Proceedings of the National Academy of Sciences.
The new study suggests that some of these current uses will be affected over this century, depending on how much fossil fuel emissions increase or decrease."If we reduced fossil fuel emissions, it would be good news for radiocarbon dating," said the study's author, Dr Heather Graven from the Department of Physics and the Grantham Institute - Climate Change and Environment at Imperial College London.
Radiocarbon dating seizes on that fraction, which decreases over time, to estimate age. The problem is that the fraction can decrease not only as carbon-14 decays but also as normal carbon increases.
That is what is happening with the burning of fossil fuels, which are so old they do not contain any carbon-14.
Nonradioactive carbon is now flooding the atmosphere, which creates a dilution effect.
Though this dilution effect is well-known, its precise scale under different emissions scenarios was not, until now.