Transitioning to virtual conferences: the impact on carbon emissions

Purpose: Today healthcare accounts for 8.5% of domestic greenhouse emissions (GHG) [1] in the United States. It is estimated that conference attendance accounts for 35% of academics' total carbon footprint [2]. As COVID-19 forced medical conferences to transition to virtual formats, numerous benefits were uncovered including increased accessibility for individuals with medical, financial, professional and/or geographic constraints. The effect of reduced travel on carbon emissions, however, remains largely unknown. We aim to highlight the reduced travel-related GHG emissions associated with virtual conferencing.

Methodology: The number of attendees to the American College of Radiation Oncology (ACRO) annual conference was collected from 2019-2021. The location of the attendees’ home institutions was identified and the distance travelled per attendee was estimated. For the 2019 in-person conference, the mode of transportation was hypothesized based on distance traveled (wheeled motor vehicles < 300 miles; airline ≥ 300 miles). Estimated associated carbon dioxide emissions were calculated based on the distance to the conference and mode of transportation for each attendee [3,4]. For the 2020 and 2021 virtual conferences, it was assumed that no travel took place. Alternatively, associated carbon dioxide emissions were hypothesized based on the distance that would have been traveled if attendees had participated in-person.

Results: A total of 1020 ACRO conference attendees were identified (270, 2019; 359, 2020; 391, 2021). A significant increase (130%) in the number of participating attendees was observed with the transition to virtual conferences in 2020 and 2021. The average carbon dioxide (CO2) footprint for in-person conference travel was determined to be 492.9 Ibs/0.22 metric tons of CO2 per person (Interquartile range [IQR], 199.7 metrics tons). In 2019, 114,502 Ibs/51.9 metric tons of CO2 were produced as a result of travel. In 2020 and 2021 a total of 165,875 Ibs and 231,786 Ibs of CO2 emissions were spared, respectively. This totals to 397,661 Ibs of CO2, the equivalent of 39.2 passenger vehicles driven for one year.

Conclusions: Incorporating options for virtual attendance at academic conferences has the potential to reduce carbon emissions and additionally address issues of accessibility and equity. However, it remains unclear whether virtual networking can adequately replace face-to-face time. Radiation oncologists and our professional societies have an opportunity to increase the overall sustainability of our annual meetings and explore ways to enhance virtual collaboration.

References: 1. https://doi.org/10.1377/hlthaff.2020.01247
2. https://doi.org/10.1016/j.ecolind.2013.05.025
3. Carbon Footprint Factsheet | Center for Sustainable Systems. Accessed November 18, 2021. https://css.umich.edu/factsheets/carbon-footprint-factsheet
4. US EPA O. Greenhouse Gas Emissions from a Typical Passenger Vehicle. Published January 12, 2016. Accessed November 18, 2021. https://www.epa.gov/greenvehicles/greenhouse-gas-emissions-typical-passenger-vehicle