The 13,000-Year-Old Man Found On A California Island — And The Dating Test That Changed The Story Of America’s First Migration

The key date — 10,960 ± 80 radiocarbon years BP, from XAD-purified collagen — became the central age estimate for the Arlington Springs individual.

But 10,960 radiocarbon years BP is not 10,960 calendar years ago.

From Radiocarbon Years To Calendar Years — Why The Difference Matters

The conversion from radiocarbon years to calendar years is one of the sources of apparent confusion in reporting on ancient sites, and the Arlington Springs case illustrates why it matters.

The problem is that carbon-14 production in the atmosphere has not been constant over time.

It varies with solar activity, with changes in Earth’s magnetic field, and with other factors.