Carbon dating for idiots
Critics of carbon dating point to these limitations, usually by pointing to the wildly inaccurate results obtained by dating very inappropriate samples, and claim that therefore carbon dating is wrong and should never be used.The fact is, of course, that the scientists who actually use it are well aware of these limitations and make sure to work within them. Usually when they carbon date sea life or something that eats sea life, since carbon dating doesn't work on sea life or anything that eats a lot of it. Scientists know it doesn't work on sea life, so they don't use it to date sea life!
Again, DUH, it's a fossil, there's no carbon in it!
Given that carbon dating is not a great deal more than 50 years old as a scientific tool, and it was a considerably blunter and less accurate version back then than now, it seems difficult to understand how an issue so long ago can be meaningful.
It is well understood that as we attempt to date things a very log time ago he accuracy declines, largely because we have to make assumptions about the rate of production of the isotopes that depend on things we know vary but can't directly know what those rates were.
From the beginning of the industrial revolution in the 18th century to the 1950s, the fractional level of 14C decreased because of the admixture of large quantities of CO2 into the atmosphere, due to the excavated oil reserves and combustion production of fossil fuel.
This decline is known as the Suess effect, and also affects the 13C isotope.