High concentration of atmospheric 14C during the Younger Dryas cold episode

The atmospheric radiocarbon ratio is sensitive to changes in the other global carbon cycle reservoirs and so the high 14C concentration in the atmosphere from the Younger Dryas period indicates a significant change. Sediments from Lake Gosciaz in Poland are used to trace climate changes and atmospheric radiocarbon for the Younger Dryas and early Holocene periods. The evidence suggests that the deep ocean ventilation rate decreased during the Younger Dryas, accounting for the high 14C concentration, most likely due to a reduced formation intensity of North Atlantic Deep Water.