Why is carbon dating inaccurate after 50000 years

When this was first done, it turned out that carbon dating had been giving too-young dates for early civilizations.Apparently, the production of C14 by the Sun has changed by several percent across the last 10,000 years.

We can't date oil paints, because their oil is "old" carbon from petroleum. And third, it is common to soak new-found fossils in a preservative, such as shellac.Plants take up carbon-14 when they convert CO2 into sugar and build cellular structures.Animals take up carbon-14 when they eat plants or other animals.It is also standard to coat fossils during their extraction and transport.Acetone is sometimes used while extracting fossils, because it dissolves dirt.