HR: 1340h
AN: B33A-1021    [Abstracts]
TI: Decrease of Emissions Required to Stabilize Atmospheric CO2 Due to Positive Carbon Cycle-Climate Feedbacks
AU: * Matthews, D
EM: dmatthew@ucalgary.ca
AF: University of Calgary, 2500 University Drive N.W., Calgary, AB T2N 1N4 Canada
AB: Positive feedbacks between the carbon cycle and climate have the potential to accelerate the accumulation of atmospheric CO₂ over the next century. Here, I address the question of how climate-induced carbon cycle changes could affect the emissions required to stabilize atmospheric CO₂ at 1000 ppmv. From a coupled climate-carbon cycle simulation, I calculated emissions that are consistent with a prescribed CO₂ stabilization pathway. By comparing a coupled simulation with a second constant-climate simulation, I show that carbon cycle-climate feedbacks led to large decreases in allowable emissions. Decrease of emissions required to stabilize atmospheric CO₂ due to positive carbon cycle-climate feedbacksCumulative emissions are reduced by 94, 230 and 754 GtC between 2005 and years 2050, 2100 and 2350 respectively. Annual differences are largest at 2080, where emissions are reduced by 2.8 GtC/year. Further while terrestrial feedbacks dominated for the next two centuries, the effect of ocean feedbacks on allowable emissions began to exceed that of terrestrial feedbacks around the year 2250.
DE: 0426 Biosphere/atmosphere interactions (0315)
DE: 0428 Carbon cycling (4806)
DE: 1225 Global change from geodesy (1222, 1622, 1630, 1641, 1645, 4556)
DE: 1615 Biogeochemical cycles, processes, and modeling (0412, 0414, 0793, 4805, 4912)
DE: 3337 Global climate models (1626, 4928)
SC: Biogeosciences [B]
MN: Fall Meeting 2005