Their work was detailed in a paper in the latest issue of the journal .
For over 50 years, scientists and researchers have relied on carbon dating to find the exact age of organic matter.
material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.
Following the development of radiometric age-dating in the early 20th century, measurements of lead in uranium-rich minerals showed that some were in excess of a billion years old.
To illustrate, suppose there is a burning candle sitting on the table. This can be calculated if the candles burn rate and original length is known.
However, if the original length is not known, or if it cannot be verified that the burning rate has been constant, it is impossible to tell for sure how long the candle was burning.
By the year 2100, the atmosphere will have a radiocarbon age of 2,000 years old. If Graven's calculations are correct, carbon dating as we know it today will no longer be reliable by the year 2030.
“Thus it is necessary to pay [special] attention when using such old carbon data for palaeoclimatic or archaeological interpretations," they added.
Prior to that, they had to depend on more rudimentary and imprecise methods, such as counting the number of rings on a cross-section of tree trunk.
This all changed in the 1940s when US chemist Willard Libby discovered that carbon-14, a radioactive isotope, could be used to date organic compounds.
The most commonly used radiometric dating methods are potassium-argon, uranium-lead, and rubidium-strontium. Half-life is simply the time required for half of the atoms in a pound of uranium, for example, to disintegrate into lead.
The concept of how these methods work is simple: one element decays into another at a rather predictable rate. If these assumptions are correct, then the radiometric dates are correct.