Demeter is a land use land cover downscaling and change detection model (Vernon et al., 2018, Chen et al. 2019). Demeter is an open source Python package that was built to disaggregate projections of future land allocations generated by an integrated human-Earth system model (e.g., GCAM). Projected land allocation from models like GCAM are traditionally transferred to ESMs in a variety of gridded formats and spatial resolutions as inputs for simulating biophysical and biogeochemical fluxes. Existing tools for performing this translation generally require a number of manual steps which introduces error and is inefficient. Demeter makes this process seamless and repeatable by providing gridded and land cover change (LULCC) products derived directly from GCAM in a variety of formats and resolutions commonly used by ESMs. Demeter is publicly available via GitHub and has an extensible output module allowing for future ESM needs to be easily accommodated.