Comment on “Climate legacies drive global soil carbon stocks in terrestrial ecosystems”

Delgado-Baquerizo et al. (Science Advances, 12 April 2017, e1602008) use statistical correlations to infer that paleoclimate (6000 to 22,000 years ago) is a more important driver of current soil organic carbon stocks than the current-day climate. On the other hand, a wealth of radiocarbon measurements indicates that the organic carbon in most topsoils is only a few decades to perhaps a few centuries old. These seemingly incongruous results can perhaps be reconciled by considering that the long-term pedogenic development of a soil strongly influences the physiochemical properties, which lead to stabilization of new carbon entering that soil regardless of current climate.