New estimates of carbon transfer to terrestrial ecosystems between the last glacial maximum and the Holocene

Ice core records of atmospheric CO2 show an approximate to 80 ppm rise betw een the last glacial maximum (LGM) and the mid-Holocene during a correspond ing world-wide expansion of the terrestrial biomass and changes in ocean ch emistry. Therefore, the absolute amount of carbon transferred to the atmosp here, probably from the oceans, remains uncertain. To address this issue, I evaluated changes in terrestrial ecosystem carbon storage and isotopic fra ctionations between the LGM and the mid-Holocene using a process-based terr estrial carbon cycle model forced with two general circulation model (GCM) simulations of each interval. The results indicate that global carbon stora ge in terrestrial ecosystems (vegetation and soils) increased by 668 Gt C d uring the last glacial-interglacial transition, a Value within the range ob tained from a revised global carbon isotope mass-balance analysis (550-680 Gt C), and consistent with independent estimates from the marine isotopic r ecord.