Please forgive the oversimplification. But radiocarbon dating, like all radiometric dating, begins with assumptions (beliefs, paradigm) and uses those beliefs as proofs of dates. Science is the accurate examination of the evidence. The evidence of radiocarbon in the remains of organism which were once alive does not produce a date. It produces a 14C:12C ratio. Then assumptions (beliefs, a paradigm) are applied to that ratio. The result is a date. But the science is only the ratio.
Regular 14N in the upper atmosphere is bombarded by cosmic rays and produces 14C, which is unstable and breaks down over time. All living organisms absorb 14C throughout their lifetime through eating and breathing. At death, the organism no longer absorbs 14C. Since 14C is unstable, it begins to break down at a steady rate. This allows us to measure the 14C:12C ratio. By applying assumptions, the end result is a date.
The group of assumptions used by Secular Humanism have a paradigm that assumes the present to be the key to the past. It assumes that formation of 14C:12C was roughly the same as 14C:12C today. Allowing for anomalies, it assumes a constant rate for 60,000 BP (Before Present) years, the maximum accurate date for 14C dating.
The flood model assumptions have a paradigm where the past is vastly different from the present. The flood changed the paradigm dramatically.
Since there are no samples to test before the flood, it is a waste of time to discuss the antediluvian condition. But we accept the standard geologic position that earlier time periods, such as what they called the Cambrian through the Jurassic, had much higher carbon levels than we have today. All of these strata were formed during the flood and represent antediluvian carbon levels.
With higher levels of 12C and 14C formed at a constant rate, the 14C:12C therefor had highly diluted levels of 14C. Therefore, any sample from this time would cause a 14C date to be much older than its actual date because of the increase in 12C, not a reduction in 14C formation.
The flood altered the 14C:12C ratio by saturating the atmosphere with volcanic aerosols laden with vast quantities of 12C. At the same time, the sluice-gates of heaven were opened. 40 days of worldwide torrential rains flushed the atmosphere of any element besides water. This included 14C. Finally, all air-breathing organisms died. The last stage of the carbon cycle, converting 14C back to 14N, did not exist.
It is important to understand that the flood paradigm assumes, just like Secular Humanism does, that 14C formation from 14N was constant throughout earth’s history. What changed, and changed greatly, was the addition of many times the regular 12C in the atmosphere compared to what we measure today. That changed the 14C:12C ratio. As the chart says, the 14C was diluted by many times the amount of 12C we measure today.
So immediately after the flood, 14C was so diluted that a sample from that time measured today would, without correcting for the additional 12C, would date to be 40,000 BP or older.
Following the blue line on the chart, the amount of 12C in the atmosphere decreased to the amount we have measured for centuries since around 600 BC.
Assuming the eruption of Thera coincided with the Exodus, then we can use it to correct 14C dates. Ussher dates the Exodus 1491 BC. 14C dates the eruption of Thera to be 1640 BC for an error of 150 years.
So 14C dates for Nebuchadnezzar’s Babylonian empire are approximately the same as Ussher’s dates. 14C dates for the Exodus, 1491 BC, are approximately 150 too old. And 14C dates for the flood are tens of thousands of years older than actual dates.
Image Credit included at the bottom of the chart