Stephen Sitcha, Victor Brovkina, Werner von Bloha, Detlef van Vuurenb, Bas Eickhoutb, and Andrey Ganopolskia
Global Biogeochemical Cycles 19, GB2013, doi:10.1029/2004GB002311 (2005)
aPotsdam Institute for Climate Impact Research (PIK),
Telegrafenberg, P.O. Box 60 12 03,
14412 Potsdam, Germany.
bNetherlands Environmental Assessment Agency (RIVM/MNP), Bilthoven, Netherlands.
Climate-carbon cycle model CLIMBER2-LPJ is run with consistent fields of future
fossil fuel CO2 emissions and geographically explicit land cover changes for four Special
Report on Emissions Scenarios (SRES) scenarios, A1B, A2, B1, and B2. By 2100,
increases in global mean temperatures range between 1.7°C (B1) and 2.7°C (A2) relative
to the present day. Biogeochemical warming associated with future tropical land
conversion is larger than its corresponding biogeophysical cooling effect in A2, and
amplifies biogeophysical warming associated with Northern Hemisphere land
abandonment in B1. In 2100, simulated atmospheric CO2 ranged from 592 ppm (B1) to
957 ppm (A2). Future CO2 concentrations simulated with the model are higher than
previously reported for the same SRES emission scenarios, indicating the effect of future
CO2 emission scenarios and land cover changes may hitherto be underestimated. The
maximum contribution of land cover changes to future atmospheric CO2 among the four
SRES scenarios represents a modest 127 ppm, or 22% in relative terms, with the
remainder attributed to fossil fuel CO2 emissions.
Keywords: Earth system modeling, biosphere-atmosphere interaction, future land cover changes, SRES scenarios, atmospheric CO2 concentration.