According to a recent study by Imperial College London atmospheric scientist Heather Graven, emissions could drastically “age” the atmosphere over the coming decades and make accurate carbon dating more hard.
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Some of the applications of radiocarbon dating include analysing archaeological finds, detecting fraudulent works of art, detection of illegal ivory trading, regeneration of brain cells in neurological patients among others. Since fossils fuels formed millions of years ago, all of their carbon-14 levels have completely decayed.
“It really depends on how much emissions increase or decrease over the next century, in terms of how strong this dilution effect gets”, she said.
“But we can also change this ratio of radioactive carbon to total carbon, if we are adding non-radioactive carbon and that’s what’s happening with fossil fuels, we get this dilution effect”.
Carbon-14 is an unusual, but naturally occuring, radioactive form of carbon that fragments over long period of time, more than thousands of years. But fossil fuel emissions threaten to make yet another victim in the near future: the technique of carbon dating. And by 2100, an object could seem the same as another object that is 2,000 or so years old. When their emissions mix with the modern atmosphere, they flood it with non-radioactive carbon.
If the current levels of burned fossil fuels are maintained, a brand new cotton T-shirt made in 2050 would appear to have almost as much carbon-14 as an object made a millennium ago.
The study claims that this effect can be easily observed in plants that absorb carbon dioxide from the atmosphere as well as products manufactured from them. But in the 1950s and 60s, nuclear weapons testing caused a sharp increase.
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The new study indicates that by 2020, the fraction of carbon-14 could drop to such an extent that radiocarbon dating will start to be affected. “How low they go depends on changes in our fossil fuel emissions“, said Dr Graven.
