Carbon dating accuracy debate
If that chronology is wrong, as many think, the calibration is wrong. But don't forget to compare to what is already available on creation.com: Dendrochronology is used to determine variations in the C14/C12 ratio, but dendrochronology has assumptions that are not always valid (see bristlecone pine dating). Yes, a decreasing magnetic field strength would allow for more cosmic rays to enter the atmosphere over time, which would induce increased rates of 14C production and throw off any ancient measurement with respect to modern values. Note the clear references to a "plateau in the calibration curve" from 2500 to 2900BC, which would be due to the flood.
When Kathleen Kenyon came away from her study in the 1950s and essentially announced ‘I see no evidence for the destruction of Joshua here,’ she was basing her opinions, in part, on the new field of radiocarbon dating.
Second, while we have discovered in recent years that certain radiometric decay rates do vary, the measured effect is slight, so far.
Third, some creationists like the members of the RATE group theorize there was a pulse of accelerated radioactive decay around the time of the Flood, but this would not apply to the post-Flood era.
This does not mean that recalibration is bad, indeed it is necessary, but it should make one more soberly assess any reported dates as being tentative.
The problem is that most people reporting on these issues fail to report the initial number along with the calibrated date. The Jericho controversy is soundly rooted in C-14 calibration.