This data set includes output data from the MBL-GEM III model for tussock tundra in the Kuparuk River watershed of Alaska. The model outputs 154 different variables for 123 10 km x 10 km grid cells, and assumes no interaction between adjacent grid cells. Diverse output variables include photosynthesis and evapotranspiration, carbon and nitrogen storage, and soil moisture and respiration, among others. Yearly model results are available for the years 1921 through 2100, with climate drivers based on historical reconstruction of climate and carbon dioxide conditions (for 1921-2000) and two possible future climate scenarios (warmer and wetter climate versus warmer and drier climate, for 2001-2100). Each file included in this 246-file data set contains simulation results for one of the 123 cells for the entire time period, based on one of the two predicted climate scenarios.