The rate of isotope decay is very consistent, and is not effected by environmental changes like heat, temperature, and pressure. This makes radiometric dating quite reliable. Because carbon-14 decays relatively rapidly compared to other isotopes, it can only be used to date things that are less than 60,000 years old.

How accurate is relative dating?

Though relative dating can only determine the sequential order in which a series of events occurred, not when they occurred, it remains a useful technique. Relative dating by biostratigraphy is the preferred method in paleontology and is, in some respects, more accurate.