Decarbonization Pathways for Canada’s Federated Energy System Using a Subnational Integrated Assessment Model

Amid growing climate risks and energy security challenges, Canada's path to Net Zero emissions by 2050 hinges on regionally differentiated transformations across its energy system. This study presents a detailed scenario-based analysis using MESSAGEix-Canada, the country's first open-source, sub-national integrated assessment model. We explore how energy system transitions evolve across provinces and sectors under varying policy pathways.Results from the Net Zero scenario indicate a 65% reduction in fossil fuel extraction, an eight-fold increase in electricity supply, and a tenfold growth in low-emissions hydrogen, achieved without significantly increasing total energy system investments relative to the Legislated pathway. Instead, capital shifts away from oil and gas production toward renewables, storage, and grid expansion. Electrification of end-use sectors, alongside carbon capture and clean hydrogen deployment, drives emissions reductions. Spatial analysis reveals Alberta, Saskatchewan, and Newfoundland and Labrador face steep structural changes in resource extraction, while provinces like Ontario and Quebec become hubs of electrification and clean energy infrastructure.The analysis highlights that achieving Net Zero is technically feasible, but demands urgent, coordinated, and province-specific strategies. Policymakers in resource-intensive provinces must plan for a managed fossil phase-out and support economic diversification. In contrast, electricity-rich provinces must scale transmission and hydrogen capacity to meet cross-sector demand. MESSAGEix-Canada provides a transparent and flexible platform to co-design such transitions with stakeholders—supporting policy alignment, investment targeting, and just transition planning within Canada's federated climate governance landscape.