National climate ambitions have been hampered by a lack of understanding of the impacts of the transition to a low-carbon economy as well as the consequences of inaction. Amid legitimate concerns regarding transitional impacts, financing needs, and the institutional and political constraints to low-carbon policy implementation, knowledge and analytical skill gaps prevent countries from increasing necessary ambition on climate and environmental targets consistent with global goals. In this Technical Note, we present the green economy model (GEM), which aims to simultaneously improve people’s understanding of complex climate, environmental, and socioeconomic linkages; equip decision-makers with adequate tools for policy development; and help close coordination gaps and build technical capacity for low-carbon policymaking. It is a practical guide for local policymakers, experts, and academics to understand the model structures and considerations for employing GEM for green economic policy analysis.