Impactful Canadian decarbonization policies in times of an uncertain carbon tax

The future of the Canadian federal carbon tax is uncertain due to a lack of public and political support, as well as an upcoming federal election. The relationship between the carbon tax and the effectiveness of other decarbonization policies is currently unquantified, whether it be synergistic or antagonistic. Prioritization of the highest impact alternative decarbonizaiton policies could aid in long-term strategy under political uncertainty. We employ the recently released MESSAGE-Canada integrated assessment model to explore decarbonization pathways wiith and without the carbon tax. For both future scenarios, a Morris sensitivity analysis of the 33 currently announced Canadian decarbonization policies will be conducted. Changes in the ranking of impact are assessed for key federal-level system indicators, such as cost and emissions. Further, policy impacts rankings on provincial metrics are also compared by scenario for major energy production and consumption provinces. Lastly, the samples generated are also used to develop a range of feasible pathway projections that better capturing Canada’s decarbonization trajectory under uncertainty. Comparing the ranking of policy impacts indicates the extent to which the carbon tax acts synergistically with other policies to reduce emissions, and thus is the most crucial lever for reaching decarbonization targets. However, this ranking also allows us to prioritize exploration of the next most effective policies in the absence of the tax.