Measuring for climate actions: a disclosure study of ten megacities

Purpose: This paper aims to explore the disclosure of greenhouse gas (GHG) emissions by megacities. Three dimensions were considered. First, what communication channels are used by world megacities to disclose their emissions reduction target (ERT) and emissions reduction actions (ERA)? Second, the consistency of disclosed ERT and ERA across different channels. Third, the quality of the disclosed ERA in different channels.

Design/methodology/approach: Ten megacities selected for review were in Australia, Europe, the USA, the UK and South Africa. First, ERT and ERA information was searched in different disclosure media to identify the common communication channels used by the megacities. Second, the documentary analysis was undertaken to assess the consistency of reported ERT and ERA information across the identified channels. Third, a scoring system was developed and applied to evaluate the quality of the disclosed ERA information, based on the extent to which megacities provided descriptions of emission reduction actions and reported the impact of the actions and the cost to implement them.

Findings: Megacities primarily used third-party channels and their channels to disclose ERT- and ERA-related information. Social media use to provide climate change information is also growing. The study also finds that ERT information is consistent between third-party channels and megacities’ channels. However, around half of the disclosed ERA between third-party and megacities’ channels are not consistent. Quality assessment for the disclosed ERA in different channels shows that megacities have provided limited information regarding the impacts and the cost of their ERA, which raises a question about the usefulness of disclosure.

Research limitations/implications: The findings are important for policymakers and city officials designing cities’ GHG reporting standards and developing policies for programs to reduce emissions. Also, for stakeholders’ understanding of cities’ commitment and actions to reduce emissions, as well as the impact of their actions, and for managers responsible for measuring, reporting and mitigating emissions from current and future actions.

Originality/value: Prior studies primarily focused on corporate greenhouse emissions disclosure to the carbon disclosure project, whereas this paper examines emissions disclosure at the geographic level. Moreover, prior studies of the public sector focused on the scope of climate change disclosure but did not evaluate the consistency and quality of the disclosure. However, this study explores three different disclosure channels and assesses consistency and quality. A further novel aspect of the study is its focus on the disclosure of emissions reduction targets and actions.