It is assumed that the ratio has been constant for a very long time before the industrial revolution.
The technique involves comparing the level of one kind of carbon atom—one that decays over time—with the level of another, more stable kind of carbon atom.
Scientists across countless disciplines rely on it to date objects that are tens of thousands of years old. An analysis by Heather Graven, a climate-physics researcher at Imperial College London, finds that today's rate of fossil-fuel emissions is skewing the ratio of carbon that scientists use to determine an object's age.
Combustion of fossil fuels is “diluting the fraction of atmospheric carbon dioxide containing radiocarbon,” Graven told , the large amount of carbon dioxide in the atmosphere will make new organic material appear to be 1,000 years old based on today’s carbon-dating models.
Recall that atoms are the basic building blocks of matter.
Atoms are made up of much smaller particles called protons, neutrons, and electrons.