Atmospheric 14 C/ 12 C changes during the last glacial period from Hulu Cave

The whole story An accurate, precise record of the carbon-14 ( 14 C) content of the atmosphere is important for developing chronologies in climate change, archaeology, and many other disciplines. Cheng et al. provide a record that covers the full range of the 14 C dating method (∼54,000 years), using paired measurements of 14 C/ 12 C and thorium-230 ( 230 Th) ages from two stalagmites from Hulu Cave, China. The advantage of matching absolute 230 Th ages and 14 C/ 12 C allowed the authors to fashion a seamless record from a single source with low uncertainties, particularly in the older sections. Science , this issue p. 1293