Multi-level climate governance: examining impacts and interactions between national and sub-national emissions mitigation policy mixes in Canada

Jurisdictions use an assortment of policies to reduce greenhouse gas emissions. Climate policy mixes have often evolved through the ad hoc layering of new policies onto an existing policy mix, rather than deliberate design of a complete policy portfolio. This can lead to unanticipated interactions between policies which can support or undermine policy objectives and is further complicated where climate policy is implemented at multiple jurisdictional levels. In the context of Canada and its four most populous provinces, we examine the development of climate policy mixes across jurisdictional levels between 2000 and 2020 and evaluate policy interactions. We develop an inventory of 184 climate policies, and examine each in terms of instrument type, implementation timing, technological specificity, and expected abatement. We evaluate interactions between overlapping policies both within jurisdictional levels (horizontal) and across jurisdictional levels (vertical) for their impact on emissions abatement using a policy coherence analysis framework. We find that subsidies and R&D funding were the most abundant policies (58%), although pricing and flexible regulation are expected to achieve the most abatement. Sub-national jurisdictions have often acted as policy pilots preceding federal policy implementation. We evaluate 356 policy interactions and find 74% are consistent in adding abatement. Less than 8% have a negative impact by reducing abatement, although vertical interactions between federal and provincial policies were more often negative (11%) than horizontal interactions at the federal (<3%) or provincial (<2%) levels. Although the impact of many interactions is unknown (13%), we generate interaction matrices as a foundational roadmap for future research, and for policy-makers to consider potential interactions when designing and assessing policy effectiveness.Key policy insights Climate policy mixes have expanded and diversified over the period 2000–2020 across jurisdictions in Canada.Sub-national jurisdictions have often acted as policy 'pilots' by implementing policy before the adoption of similar national level policy.Climate mitigation policy interactions are predominantly supportive toward achieving additional emissions abatement.Vertical interactions between federal and provincial policy can undermine the additionality of policy effort by sub-national jurisdictions.These findings emphasize the need for better coordination in climate policy mix design between national and sub-national jurisdictions.