Assessing Subnational Climate Action in G-20 Cities and Regions: Progress and Ambition

Abstract

Cities and regional authorities play a crucial role in driving climate action to limit global warming to 1.5°C. Despite their critical importance, significant obstacles in data collection and variability in implementation complicate the assessment of their contributions. This study provides the largest analysis of climate efforts across more than 3,000 cities and 175 regions within the G20 nations, revealing a noticeable uptick in the adoption of medium- to long-term emission reduction and net-zero targets post-2020. However, over 60% of these subnational entities are failing to meet their climate ambitions, with a larger percentage not achieving the reduction rates necessary to align with the 1.5°C goal. These findings underscore the pressing need for enhanced accountability mechanisms for subnational climate actions. Implementing standardized reporting and boosting transparency are pivotal steps to ensure that local and regional efforts substantively contribute to achieving both national and global climate objectives.

Keywords: Subnational climate action, emission reduction targets, climate policy implementation, climate ambition, science-alignment, G20 nations