A new study has come to a rather alarming finding: scientists think that if pollution levels keep rising, carbon dating may become greatly altered.

A study by the Imperial College London findings that emissions could cause the atmosphere to “age” over the coming years and decades, therefore making it far more difficult to age things via carbon dating, according to a SlashGear report.

Emissions often have a “dilution” effect, which scientists have to account for, but in this case it appears that effect could be drastic.

Scientists examine radioactive carbon-14 in an object and uses it to determine how old something is that contains it. They are concerned that fossil fuel emissions, while they don’t have carbon-14, are artificially increasing carbon levels and making objects seem older than they are in reality.

For example, if scientists find an object in 2050 and use the same carbon dating, they may find that it is a thousand years older than it actually. And in 2100, the difference could be 2,000 years.

The study said, somewhat dramatically, that a shirt made in 2050 would have the same radiocarbon date as a robe worn by William the Conqueror at a certain point.

While that might seem amusing, it’s serious business for scientists, who use carbon dating for assessing artwork and analyzing historical discoveries. Even a slight alteration in the accuracy of carbon dating could make this type of measuring useless at least for artifacts in the last few thousand years.

Radiocarbon dating was invented in the late 1940s and has since become the gold standard for archaeologists who attempt to accurately date ancient discoveries. The finding earned the discoverer, Willard Libby, the Nobel Prize in 1960.