Human land-use activities have resulted in large changes to the biogeochemical and biophysical properties of the Earth surface, with impact on climate. Land-use activities are likely to expand and/or intensify further to meet future demands for food, fiber, and energy. CMIP5 achieved a qualitative scientific advance in studying the effects of land-use on climate, for the first time explicitly accounting for the effects of global gridded land-use changes (past-future) in coupled carbon-climate model projections. Enabling this advance, the first consistent gridded land-use dataset (past-future) was developed, linking historical land-use data to future projections from Integrated Assessment Models in a standard format required by climate models (“Land-use Harmonization”). Results indicate that the effects of land-use on climate, while uncertain, are sufficiently large and complex to warrant an expanded treatment of land-use. The overall science goal of this proposal is to understand the effects on land-use activities  (past-future) on the coupled carbon-climate system. In particular, we seek to address the following major science questions:

·      What is the sensitivity of the climate system to potentially altered land-use activities?

·      How have land-use activities (past-future) altered relevant land-surface properties important for climate prediction?

·      What are the effects land-use activities on the climate system past-future?

To address these questions, we will build upon and integrate our team’s leadership experience and ongoing efforts in land-use modeling, climate modeling, remote sensing, and integrated assessment. The proposal has three major objectives: 1: Develop metrics to quantify climate sensitivity to land-use/land-cover change using DOE-ESM/CESM; 2: develop new essential input data products and algorithms for land-use in DOE-ESM/CESM (past-future); and 3: design model experiments to isolate and quantify the effects of land-use on climate in DOE-ESM/CESM. Through these objectives, we will innovate and marry advanced climate modeling, land-use modeling, terrestrial ecosystem modeling, integrated assessment, and remote sensing to develop and apply models of the human-natural Earth system informed with the best possible information to isolate the effects of human land-use activities on the climate system. Ultimately, this research will inform policy decision making. Land-use change is a critical driver of climate change. As such, the proposed research is cross-cutting and relevant to all three FOA elements.