Burning of fossil fuels may adversely affect radiocarbon dating

BBC : Not only are fossil-fuel emissions affecting Earth’s climate, but now it has been shown that they may diminish the effectiveness of an important technique for determining the age of objects—radiocarbon dating. Radiocarbon, or carbon-14, is created in the atmosphere when cosmic rays interact with atmospheric nitrogen. It is then absorbed by plants via photosynthesis and by animals that eat the plants. When the plant or animal dies, it stops absorbing ¹⁴C and the remaining ¹⁴C begins to decay. That decay rate can be used to calculate the organism’s age. Radiocarbon dating was developed in the late 1940s and has been used for various purposes, including the dating of ancient artifacts. With so much nonradioactive carbon being pumped into the atmosphere, however, the ratio of radioactive to nonradioactive carbon is becoming diluted, which makes objects appear to be older than they really are. That artificial aging of the atmosphere, which is worsening as fossil-fuel emissions increase, could have implications for a range of fields, including Earth science, archaeology, forgery detection, isotope forensics, and physiology, according to a study published in the Proceedings of the National Academy of Sciences.