Ireland Before Settlement
Calendar-year precision disappears rapidly in the Upper Palaeolithic. Radiocarbon measurements are reported as years “BP” — before AD 1950 — and must be calibrated against changing atmospheric carbon levels to estimate calendar ages. Near 34,000 years ago, dates may carry uncertainties of centuries or more; cave deposits can also contain bones accumulated at different times and later disturbed by water, animals or excavation. A specimen dated to a broad interval around this period is evidence for that interval, not for an event occurring on 1 January or any other day in 31,993 BCE.