The objective of this project is to assess the effects of anthropogenic land cover changes on exchanges of water, energy, and momentum between the biosphere and atmosphere and consequently on global patterns of temperature and precipitation. We are constructing global data sets for 1) land cover undisturbed by anthropogenic activity and 2) plausible future scenarios of land cover. The proposed methodology to develop these data sets involves the use of the NOAA/NASA AVHRR Pathfinder and Landsat data, as well as historical information and existing maps of potential vegetation. Secondly, we are using these global land cover data sets along with a sophisticated land surface model, the Simple Biosphere model (SiB2). The land cover data sets are also being used to simulate climate with SiB-2 coupled to the Colorado State University General Circulation Model to assess the effects of land cover changes on global and regional climate. Present-day climate is assumed in the model runs to quantify the effects of changes in land cover only. The "control" for these experiments is a data set of global land cover derived from satellite data currently being developed by the principal investigator under separate funding. Differences in model outcomes between the "control" and "experiments" are being used to infer the effect of global changes in land cover from anthropogenic activity on climate. The data sets developed in this project will be made available to the larger modeling community for other potential applications.