Use of fossil fuels are making carbon dating more difficult.
According to a new study released Monday, the burning of fossil fuels is causing the carbon dating process to give erroneous results that could make a specimen seem much older.
The study from the Proceedings of the National Academy of Sciences found carbon emissions are raising the carbon age of the atmosphere, accounting for the incorrect readings.
A story in the Washington Post references the study by Imperial College London in which Physicist Heather D. Graven stated by 2050, today’s new clothes could appear to be as much as ten centuries old.
Carbon dating is a process that measures the amount of Carbon-14 in a object. Carbon-14 is manufactured in the atmosphere and is absorbed by plants and animals until they die. Since Carbon-14 is radioactive, it decays at a predictable rate each year, so the amount remaining can tell scientists how long ago an object was alive.
The process, developed in the 1940’s, allowed archeologists to more accurately date objects, and rapidly became an accepted technique.
Burning of fossil fuels, which contain Carbon-14 that has already decayed, releases “dead” carbon into the air, and in turn dilutes the proportional amount of Carbon-14. Organic matter growing today will ingest less Carbon-14 than matter grown more than 125 years ago, before the widespread use of fossil fuels.
That doesn’t mean carbon dating will no longer be used. Scientists are aware of the atmospheric differences and can re-calibrate their equipment to adjust for the differences. The process will become more difficult and slightly less accurate than before.
Graven doesn’t believe carbon dating will be able to provide accurate dating for objects less than 2,000 years old if current levels of emissions are maintained. However, the more fossil fuels burned, the less accurate the process will be.
Carbon dating is not the only tool available to scientists. Another process looks at the change in amino acids to achieve a similar result.