Estimating scope 3 greenhouse gas emissions through the shareholder network of publicly traded firms

Accounting for scope 3 emissions from investments remains a challenge due to a lack of adequate data and guidelines that do not accommodate the systemic role of firms in the financial chain. Here, we use network analysis to estimate investment-associated scope 3 carbon emissions of public firms. Using shareholder data from publicly traded firms listed on the Tokyo Stock Exchange, we identified the most influential firms by their ownership share values. Environmental responsibility can then be assigned by distributing the carbon footprint in the network to each of these influential firms. The industrial services, including trading and manufacturing, and financial services industries were found to be the largest source of scope 3 emissions in the investment network. In particular, the influential role of financial firms is reflected by having the largest increase in carbon allocation after the adjustment. This research contributes to ongoing efforts to improve carbon disclosure through methods that accommodate complex interactions among firms and to quantitatively reveal the overlooked responsibility of investors in carbon emissions.