Fossil emissions mess with dating

Researchers in the UK have suggested that fossil fuel emissions could soon make it impossible for archeologists and others to use radiocarbon dating reliably to distinguish new materials from artifacts that are hundreds of years old. Carbon that has been trapped underground for millions of years is released by the burning fossil fuels and is diluting radioactive carbon-14 to raise the radiocarbon 'age' of the Earth's atmosphere, according to Heather Graven and colleagues at Imperial College London writing in the journal Proceedings of the National Academy of Sciences. At current fossil fuel carbon emission rates, by the year 2050 a new T-shirt will give the same radiocarbon date as a robe worn by William the Conqueror!