Impact on carbon emissions of online study for a cohort of overseas students: A retrospective cohort study [version 4; peer review: 2 approved, 1 approved with reservations]

Background: One of the benefits of online education is the potential reduction in carbon emissions through the decrease in travel to attend a university in person. We estimated the savings in CO 2 emissions of an international cohort of master's students who studied fully online from their home countries, rather than travelling to the UK and living there while attending university. Methods: The city and country of residence of a cohort of students who first enrolled in the fully online Peoples-uni/Manchester Metropolitan University Master of Public Health programme between the second semester of 2011 and the first semester 2013 were recorded. Total difference in emissions was calculated by adding the estimated aviation emissions between Manchester, UK and the cities where students resided, to the difference in per capita emissions between the country of origin and the UK for the time that the student would have spent in Manchester, based on the semester in which they first enrolled. Results: 128 students enrolled from 55 cities in 31 countries. 93 students were from a range of African countries and 18 from the Indian sub-continent. Flights to and from Manchester were estimated to have accounted for 114,553kg of CO 2 and living in Manchester for the duration of their course compared with staying in the home country would have been equivalent to 854,904kg of CO 2. The combined net savings was 969,457kg of CO 2. Conclusions: A small cohort of overseas students, largely from Africa and India, studied online rather than attending university in the UK. The likely saving by this small cohort of nearly a million kg of CO 2 emissions offers an indication of the potential environmental benefits of offering university education online to overseas students.