Plants, and the animals that eat them, absorb radioactive carbon-14 and stable carbon-12 from the atmosphere in proportions which – except during the atmospheric nuclear weapons tests in the 1950s and 1960s − have not changed much from the Ice Ages to the beginning of the Industrial Revolution.
When the tree dies or the animal becomes old bones, the carbon-14 decays at a predictable rate, and the ratio that remains in the laboratory sample is a measure of the specimen’s age.
But Heather Graven, a lecturer in climate physics and Earth observation at Imperial College London, reports in the US journal Proceedings of the National Academy of Sciences that by 2020, as the fossil fuel emissions mount up, the fraction of carbon-14 in the atmosphere could drop to such a level that carbon-dating could become increasingly uncertain.
Fossil fuels are reservoirs of carbon from plants and algae that died so long ago that all the carbon-14 has decayed.
This made me realise that fossil fuel emissions are likely to have an impact on these various uses for radiocarbon.
Much of the information presented in this section is based upon the Stuiver and Polach (1977) paper "Discussion: Reporting of C14 data". 1890 wood was chosen as the radiocarbon standard because it was growing prior to the fossil fuel effects of the industrial revolution.
– Climate change driven by increasing levels of atmospheric carbon dioxide will not just damage the health of the planet.