Postglacial Terrestrial Carbon Dynamics and Atmospheric CO2

Combining PMIP climate model results from the last glacial maximum (LGM) with biome modelling indicates the involvement of both cold, dry climate and physiological effects of low atmospheric CO2 in reducing tree cover on the continents. Further results with the LPJ dynamic vegetation model agree with independent evidence for greatly reduced terrestrial carbon storage at LGM, and suggest that terrestrial carbon storage continued to increase during the Holocene. These results point to predominantly oceanic explanations for preindustrial changes in atmospheric CO2, although land changes after the LGM may have contributed indirectly by reducing the aeolian marine Fe source and (on a longer time scale) by triggering CaCO3 compensation in the ocean.