Equity-Based Emissions Allocations in Multi-Level Governance

Local governments are widely adopting voluntary emissions targets to contribute to their fair share of global mitigation efforts. Limited research, often from grey literature and developed with local governments, have adapted national fair-share approaches to quantify subnational-level emissions allocations for a few cities, based on equity considerations. Frequently presented as “Paris-aligned” or “1.5°C-compatible,” these allocations do not account for limitations of subnational governance, such as insufficient regulatory authority or financing, and are often unachievable by cities alone. Here we present the first multi-level equity-based framework that derives emissions allocations consistent across national and subnational levels of government globally. We derive emissions pathways for 3,596 local governments worldwide, based on the Paris Agreement equity principles, and use them to assess the ambition of the emissions targets of 160 subnational governments and 70 cities. Compared to national pledges, we find that local level targets are often more ambitious, but that achieving 1.5°C-allocations require important vertical and horizontal cooperation. To achieve these allocations, we suggest that local governments communicate their quantified “governance-dependent ambition gaps” as the regulatory and financial support needed from other levels of governments, and the possible international support implied by their population’s equity indicators.