Carbon footprint estimation of campus mobility in a Japanese higher education institution

<b>This study aims to analyse and quantify the carbon footprint resulting from campus mobility of students and staff at Sophia University during the spring semester of 2023 at the Yotsuya campus by implementing the widely known GHG protocol's Scope 3 framework. Through the development and implementation of an online survey, mobility-related data and tele-conferencing information were collected to identify key factors influencing the carbon footprint of Sophia University. The study evaluates the contribution of various mobility activities, including initial relocation trips to Tokyo, daily mobility, and events related to university business. Additionally, it examines the impact of existing initiatives such as tele-learning and tele-working on reducing travel emissions. Based on the collected data and the adoption of different scenarios, alternative transportation strategies aimed at reducing indirect emissions are proposed.</b><b>This research represents the first estimation of a higher education institution's carbon footprint in Japan considering indirect emissions related to transportation. Leveraging regularly published energy consumption data, passenger volume information, and emission factors for various fossil fuels and greenhouse gases at the national level, the study developed an approach similar to the GHG protocol, aligning with other universities worldwide in considering scope 3 emissions related to transportation activities. The study successfully quantifies the carbon footprint and analyses the contribution from different stakeholders. The findings underscore the potential of teleconferencing strategies in marginally reducing the environmental burden associated with campus mobility. Consequently, proposed alternatives and emissions reduction scenarios are examined to transform the campus into a more sustainable environment.Interviews were conducted both on-site and via email with Sophia University members, resulting in a sample size of 400 participants and 377 valid responses. The results indicate that foreign nationals, particularly faculty members, contribute significantly to emissions due to air travel for relocating to Tokyo and attending domestic and international events. Per capita carbon emissions in Sophia University were relatively lower compared to other higher education institutions, attributed to the widespread use of railway transportation for daily commuting and the relatively high acceptance and use of teleconferencing tools among the university community.</b><b>Continued promotion of teleconferencing tools, installation of bike storage infrastructure, and encouragement of cycling commuting are identified as strategies to further reduce emissions and foster sustainable choices within the university community. While these strategies primarily address daily mobility, which constitutes a smaller portion of the total emissions generated by campus mobility, additional and more ambitious measures are required to address air travel by students returning home and come back to resume their studies in Japan, as well as faculty members with demanding international agendas. Implementing such measures has the potential to significantly reduce the carbon footprint. The study acknowledges limitations concerning sample size, data currency, and comparative analysis, emphasising the need for larger sample sizes and broader assessments to ensure robust findings and a comprehensive understanding of the topic.</b><b>Finally, this study emphasises the importance of regularly estimating GHG emissions from campus mobility and integrating the results into annual non-financial disclosure elements. Future research should focus on comprehensive estimation of scope 3 emissions and analysis of scope 2 emissions related to electricity purchases. It is essential to foster university support and collaboration to promote sustainability and prioritise environmental considerations. Addressing inconsistencies in emissions estimation and refining methodologies will enhance the accuracy and credibility of assessments.</b>