Studying online instead of on campus - this can significantly reduce the CO₂ emissions of universities, as a new study shows. Digital formats are an important building block on the road to an environmentally friendly university, but they are not a panacea.
Universities are also expected to reduce their greenhouse gas emissions. However, little research has been conducted into the extent to which teaching and learning formats other than traditional face-to-face teaching on campus can contribute to this. A meta-study by Olaf Zawacki-Richter and Berrin Cefa from the University of Oldenburg now offers a systematic overview for the first time. The study will be presented at the 30th World Congress of the International Council for Open and Distance Education (ICDE ) in New Zealand.
Significant decrease in emissions
The study analyses 17 research papers from the years 2002 to 2025 that deal with the carbon footprint of digital distance learning (Open, Distance and Digital Education, ODDE). The results are briefly summarised: The alternatives to campus-based learning generally cause far lower emissions. The greatest influence is the significantly reduced volume of traffic, as commuting by students and lecturers as well as international travelling are eliminated. The lower energy requirements for buildings and canteens are also relevant. In addition, online services can be centralised and therefore provided more efficiently.
In the most informative studies, particularly by the British Open University Team, over 80 per cent fewer emissions were identified for digitally supported and location-independent learning formats than for face-to-face events. One reason for much of the research was the switch to digital teaching as a result of the Covid-19 pandemic. This led to measurable reductions in CO₂ emissions from universities worldwide. For example, greenhouse gas emissions at Bournemouth University fell by 29 per cent in 2020 compared to the previous year. At universities in the Philippines and Thailand, the figure was up to 60 per cent.
Do savings evaporate due to rebound effects?
While the climate effects initially appear convincing, several studies point to so-called rebound effects. Working and learning from home increases the energy consumption of private households. As university buildings continue to consume basic energy, for example for technology or administration, the savings remain limited. The shift to digital also causes new environmental impacts: The production and disposal of billions of electronic devices and the consumption of resources in Data Centres are set against the lower expenditure on university campuses.
The few existing research studies - one in three comes from the UK - that scientifically analyse the carbon footprint of teaching methods are assessed in the meta-study as initial approaches to the topic. Most studies focus on easily measurable factors such as energy consumption and transport, while more complex indirect emissions from private mobility or working from home remain underexposed. There is a lack of internationally recognised standards and comprehensive survey instruments to consistently record the actual effects of different teaching methods. More comparative research, systematic data collection and binding criteria for the ecological footprint of educational programmes are therefore needed.
How can higher education become more environmentally friendly?
The study provides key findings for educational institutions: Alternatives to face-to-face teaching - if they are implemented sustainably and combined with renewable energy - can make a significant contribution to a climate-friendly university. Although non-campus-based formats are not a panacea, they are an important building block. As both direct and indirect influences need to be taken into account, ecological strategies should not be limited to teaching formats. The conclusion of the research team from Oldenburg: ODDE can be good for the environment, but further research into the ecological rebound effects of digital education is needed to enable a responsible and informed selection of technologies.
Zawacki-Richter, O.; Cefa, B. (2025): Is Open, Distance, and Digital Education (ODDE) good for the environment? A systematic review of carbon footprint studies
The study is available at https://osf.io/preprints/edarxiv/dcfx7_v1