Earth system models are the only scientific tools yet developed that are capable of integrating the multitude of physical, chemical and biological processes that determine past, present and future climate. Researchers here use the Community Earth System Model (CESM) to generate depictions of environmental futures under climate change specifically to serve stakeholder needs for each of the major Great Lake watersheds. These predictions offer state-of the-science guidance for a multitude of environmental variables such as water provision and runoff, extreme climatic events, net primary production and carbon stocks, and provide inputs into GIS modeling of sedimentation and erosion, lake hydrodynamic models of nutrient transports influencing fish stocks, and to inform long-term carbon sequestration initiatives by assessing forest viability, among many other applications. This research demonstrates a range of predictive products that indicate the increasingly stressful conditions likely to occur over coming decades across the lake watersheds and the lakes themselves, and elaborates on their impact upon human activities, agriculture and ecosystem services. Researchers aim for earth system modeling to become recognized as a highly effective and versatile tool kit for understanding environmental response to climate change, and for their modeling products, made available through a project website, to be widely utilized by Great Lakes region conservation interests to serve their planning needs.