Carbon-neutral cities: Critical review of theory and practice

Carbon neutrality has become central in policy discourse and cities’ climate actions are crucial to achieve this goal. Consequently, many cities have already published ambitious climate neutrality target years and are preparing for transition to climate neutrality. This study presents findings from the first ever literature review on the carbon-neutral city concept, covering definition, assessment approaches, and barriers and drivers for transition to carbon neutrality. These findings are combined with interviews with Finnish cities aiming at carbon neutrality to explore gaps between research and practice. More clarity is needed on the definition of carbon-neutral city concept and especially on the role of offsetting the emissions (a specific feature compared to other urban climate concepts). The lack of consistency in city carbon accounting methods and emission scopes making cities’ carbon neutrality goals incomparable, thus calling for harmonization and guidance on common assessment methods. In addition to research, climate networks play an important role in the transition to carbon neutrality. Cities have set ambitious goals and need support to develop action plans, assess actions, come up with creative and innovative ideas and increase collaboration with various stakeholders. Development of ways to support cities that have taken on ambitious carbon neutrality targets would benefit from more systematic research on transition to carbon neutrality from different contexts capturing the lessons learned. There is a need for methods that are flexible enough to accommodate adjustments to local conditions and needs, but also consider broader system transition.