© Agence France-PresseThe Kongsfjorden fjord in Norway. Scientists have for over half a century.relied on carbon dating to gauge the age of organic matter and help determine when some events happened.
Radiocarbon dating, which is used to calculate the age of certain organic materials,
has been found to be unreliable, and sometimes wildly so - a discovery that could upset previous studies on climate change, scientists from China and Germany said in a new paper.
Their recent analysis of sediment from the largest freshwater lake in northeast China showed that its carbon clock stopped ticking as early as 30,000 years ago, or nearly half as long as was hitherto thought.
As scientists who study earth's (relatively) modern history rely on this measurement tool to place their findings in the correct time period, the discovery that it is unreliable could put some in a quandary.
For instance, remnants of organic matter formerly held up as solid evidence of the most recent, large-scale global warming event some 40,000 years ago may actually date back far earlier to a previous ice age.
"The radiocarbon dating technique may significantly underestimate the age of sediment for samples older than 30,000 years," said the authors of the report from the Chinese Academy of Sciences and Germany's Leibniz Institute for Applied Geophysics.
"Thus it is necessary to pay [special] attention when using such old carbon data for palaeoclimatic or archaeological interpretations," they added.
Their work was detailed in a paper in the latest issue of the journal
Earth and Planetary Science Letters.
For over 50 years, scientists and researchers have relied on carbon dating to find the exact age of organic matter.
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.
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