Based on the estimates we present here of carbon emissions associated with flying and driving to and from Houston, we determined that converting the 2021 CUGH conference from an in-person to a virtual format averted 2,443.82 MtCO2 emissions. Moreover, these estimates are conservative in that they did not include additional sources of emissions, such as travel to and from airports, accommodation and food, and single-use paper brochures, which would have contributed to even greater carbon costs. To put these findings in perspective, 2,443.82 MtCO2 is the emissions equivalent of 13.5 railcars of coal burned, 294 US homes’ energy use for one year, or 274,988 gallons of gasoline consumed. To offset those emissions, one would need to preserve 2,994 acres of U.S. forest for a year, grow 40,409 tree seedlings for a decade, or switch 92,623 incandescent bulbs to LEDs.14
Academic sectors other than health have questioned the benefits of in-person meetings because of the very large carbon cost of travel. Even before the COVID-19 era, when many meetings transitioned to virtual formats, some academics in the ecological sciences suggested embracing virtual conferencing for environmental reasons.15 Since the effects of climate change extend beyond environmental impacts and directly affect human health through such phenomena as rising sea levels, unbearable temperatures, and catastrophic weather events, especially in low-income and middle-income countries with vulnerable health infrastructure, it is important to consider how virtual versus in-person conferencing reflects the goals of medicine and global health.3,16 The differences in climate change-related helath impacts are also relevant when examining the relative per capita carbon emissions of high-income versus lower-income countries. For example, in 2018 the US emitted 13.2 MtCO2 per capita, while the least developed countries (by UN classification) averaged 0.335 MtCO2 per capita.17 These data and considerations are particularly germane for CUGH since the mission is “to improve the wellbeing of people and the planet through education, research, service, and advocacy.”18
There are, of course, valuable and intangible aspects of in-person conferencing that cannot be recreated in a virtual format, such as networking and meaningful intercultural interactions. These benefits have been examined by other global health-focused scholars.19,20 They can be essential to forming impactful partnerships between the Global North and Global South. There are aslo quantifiable benefits to in-person meetings, such as the formation of collaborations that result in increased research productivity.8
Virtual conferencing has the advantage of accessibility and equity. CUGH conferences have previously been held in the US, which poses financial barriers to participants from low- and middle-income countries. Virtual conferencing eliminates those barriers.
The COVID-19 pandemic has triggered a rapid shift to online fora, and in consequence virtual meeting software has improved and become more easily accessible worldwide. Many have found that virtual meetings are valuable tools for education and dialogue in the COVID-19 era and are considering holding online conferences indefinitely.21–23 The ready availability today of open-source carbon calculation formulas greatly facilitates such accounting and makes it possible for organizations to quantify each registrant’s travel-related carbon footprint and the aggregate the emissions of all conference registrants and provides a basis for transparent environmental accounting.24.
The concept of environmental accounting as a form of social responsibility has already been embraced by other healthcare entities such as in an EPA-AHA MOU in 2000 and more recently in the Planetary Health Report Card for medical schools.25,26 Although these publications have not yet directly reduced institutions’ carbon emissions, they have increased social awareness surrounding the effects of climate change on human health and indirectly catalyzed change at an institutional level. Similarly, making visible CUGH’s carbon emissions would further elevate the current dialogue regarding planetary health, ideally leading to more advocacy, education, and research innovation in line with CUGH’s mission.
The estimates we present here are limited by several assumptions. For example, we do not know if all attendees reflected in this analysis would, in fact, have attended the conference in person had it been held in Houston. However, the number of registrants for this conference was only marginally greater than the number who attended the last in-person CUGH conference held in 2019 (personal communication, CUGH secretariat). We also assumed that all registrants would have taken the most direct flights or driving routes available. We likely underestimated the total carbon emissions from an in-person event because we did not account for emissions from hotel, food, other ground travel, and single-use items such as paper pamphlets because these emissions were small compared to that of air travel. On the other side of the equation, we did not measutre the carbon footprint associated with internet usage in support of virtual conferencing. Although, it is relatively small, this carbon footrprint is greater than zero.