Climate change impacts the terrestrial carbon, water, and energy cycle with important feedback effects on the global climate system. In order to adapt to future climate change, we must understand the response of terrestrial carbon, water, and energy cycles to a warming climate, increased atmospheric CO2 concentrations, land-use and land cover change, disturbances, vegetation shifts, and accelerated nutrient cycling. It’s also important that we quantify the impact of these processes in critical ecosystems including boreal forests, peatlands, and Arctic ecosystems. Process-based models, inventory-based estimates, atmospheric inversions, remote sensing observations, and data-driven approaches are powerful tools for approaching these problems. This session will showcase research focused on improving our understanding of the Canadian and global terrestrial carbon, water, and energy cycles by providing insights into how best to represent these complex systems and reduce uncertainties. We especially encourage submissions that can inform the development of process-based models, in particular studies that utilize the Canadian Land Surface Scheme including Biogeochemical Cycles (CLASSIC), which is the community open-source successor to the coupled Canadian Land Surface Scheme (CLASS) and Canadian Terrestrial Ecosystem Model (CTEM) framework and the land surface component of CanESM.