Until recent years, scientists who believe in creation haven't had the necessary resources to explore radiometric dating in detail.
When a living thing dies, its radiocarbon loss (decay) is no longer balanced by intake, so its radiocarbon steadily decreases with a half-life of 5,730 years.
If we knew the amount of carbon-14 in an organism when it died, we could attempt to date the time of death.
If the atmosphere's ratio of carbon-14 to carbon-12 has doubled since the flood and we did not know it, radiocarbon ages of things living soon after the flood would appear to be one half-life (or 5,730 years) older than their true ages.
If that ratio quadrupled, organic remains would appear 11,460 (2 x 5,730) years older, etc.
Actually, that ratio may have been quite different.