Quantifying the climate benefits of a virtual versus an in-person format for an international conference

BACKGROUND: Academic institutions across the globe routinely sponsor large conferences. During the COVID-19 pandemic, many conferences have used all- or partially virtual formats. The conversion of the 2021 Consortium of Universities for Global Health (CUGH) conference, originally planned in-person for Houston, TX USA to an all-virtual format provided an opportunity to quantify the climate-related impacts of in-person versus virtual conferences. METHODS: From the 2021 CUGH conference registration data, we determined each registrant’s distance from Houston. Using widely available, open-source formulas, we calculated the carbon footprint of each registrant’s round-trip drive or flight had they traveled to Houston. We assumed that registrants traveling more than 300 miles would have flown, with the remainder traveling by automobile. RESULTS: Of 1909 registrants, 1447 would have traveled less than 4000 miles, and 389 would have traveled more than 10,000 miles round trip. Total travel-related carbon emissions were estimated at 2436 metric tons of CO(2), equivalent to the conservation of 2994 acres of forest for a year. CONCLUSIONS: Organizations can now readily quantify the climate cost of annual conferences. CUGH’s annual international conference, when held in-person, contributes significantly to carbon emissions. With its focus on promoting global health equity, CUGH may play a lead role in understanding the pros and cons for planetary health of in-person versus virtual conferences. CUGH and other organizations could routinely measure and publish the climate costs of their annual conferences.