The L2A85 simulation is the model run without landuse change (after yr 2005) and with atmospheric CO2 concentration prescribed from the RCP8.5 scenario. This would provide biogeophysical effect of the landuse change by a difference in climate between the L2A85 and CMIP5 4.2 runs. The landuse emissions could be figured out as a difference in land-atmosphere CO2 fluxes between the L2A85 and CMIP5 4.2 runs. (Core simulation)
( see http://www.mpimet.mpg.de/en/science/the-land-in-the-earth-system/climate-biogeosphere-interaction/lucid-cmip5/experiments.html )