The data represent monthly average values from the fossil fuel CO2 emission experiment for the MPI-M Millennium Project (http://www.mpimet.mpg.de/en/wissenschaft/working-groups/millennium.html) using the comprehensive MPI-M Earth System Model ECHAM5/JSBACH/MPI-OM/HAMOCC including the biogeophysical and biogeochemical effects of an interactive carbon cycle. This experiment is similar to the mil0008 experiment (see http://cera-www.dkrz.de/WDCC/ui/Entry.jsp?acronym=mil0008) except that vegetation cover (land use) is fixed, only the time-dependend fossil fuel CO2 emissions are prescribed. The model is restarted from the mil0002 state at the end of 1859 and run from 1860 to 2100. The vegetation cover is held fixed at the (annual) map of 1860. For 1860-2000 regional fossil fuel CO2 emissions are from Marland et al. 2003 (Global, regional and national emissions. In: Trends: a compendium of data on global change. Carbon Dioxide Information Center, National Laboratory, U.S. Department of Energy, Oak Ridge, see http://cdiac.ornl.gov/trends/emis/em_cont.htm). For 2001-2100 global CO2 emissions are adopted from the SRES A1B scenario and distributed proportional to the Marland et al. (2003) regional emissions in 2000. All these fossil fuel CO2 emissions are allocated within the regions proportional to population density (K. Klein Goldewijk, 2005: Three centuries of global population growth: a spatial referenced population density database for 1700-2000, Population and Environment, 26, 343-367). Technical details: The experiment used the following models/resolutions: ECHAM5 (EH5) Version 5.4.01 at T31L19 resolution JSBACH (JSB) at T31 resolution, one soil layer, 13 vegetation types and four vegetation tiles per grid box MPI-OM/HAMOCC Version 1.3.0 at GR3.0L40 resolution The output from the experiment is archived at hpss:/dxul/ut/9/prj/im0387/m212098/cosmos-1.1.0_millennium/experiments/mil0024