Greener Websites: A Digital Carbon Footprint Audit of Higher Education Homepages Across the UNITA Alliance

Higher education institutions increasingly rely on digital infrastructures, but these systems also contribute to carbon emissions through their digital carbon footprint. Institutional websites are an important part of this footprint, serving both as sources of emissions and as platforms for communicating sustainability initiatives. This study evaluates the carbon footprints of the homepages of the 12 member and associate university websites of the UNITA Universitas Montium Alliance, a European Universities Initiative focused on digital transformation and sustainability. Using the Website Carbon Calculator (v4), an audit conducted in June 2026 measured CO2e emissions per page view, estimated annual emissions under standardized traffic, hosting energy use, and the number of trees required to offset emissions. Results showed considerable variation, with ratings ranging from B to F and emissions between 0.08 and 2.38 g CO2e per page view. Five institutions already use green hosting. The same 12 homepages were re-measured under an identical protocol on 20 July and 17 August 2026; eleven returned identical values in all three rounds and the twelfth varied by 0.05 g CO2e per page view. These findings extend a technical carbon-footprint auditing methodology previously validated only within single-country university systems to a comparative, multi-country alliance setting, and are consistent with website design and hosting choices, not national electricity grids, playing the dominant role in the observed differences between institutions. For UNITA, this points to a concrete opportunity to coordinate action through its existing Green Sustainability and Virtual Campus work packages, aligning the alliance’s digital infrastructure with the sustainability standards it already promotes elsewhere.