Publication Date



Many universities interested in sustainability have calculated their carbon footprint. The carbon footprint is well-established and understood: it tells us how much carbon dioxide and other greenhouse gases are emitted to the atmosphere as a result of university activities. While important, this calculation addresses just one part of a university’s environmental impact. Universities that want to expand their approach to sustainability can now also calculate their nitrogen footprint.

Nitrogen footprints connect entities, such as individuals or universities, with the reactive nitrogen (all species of nitrogen except N2) lost to the environment as a result of their activities. While necessary to life, excess reactive nitrogen can be detrimental to ecosystem and human health, causing impacts such as smog, eutrophication, biodiversity loss, climate change, and more. The nitrogen footprint differs importantly from the carbon footprint in that its impact is not only global but also local, impacting local watersheds and ecosystems. Addressing nitrogen allows us to protect and enhance the communities and landscapes of which we are directly a part.

Tools are now available to help individuals, universities, and other institutions calculate and reduce their nitrogen footprint. A nitrogen footprint analysis generally considers energy usage, food production and consumption, fertilizer usage, and—especially for a land grant institution—agricultural activities related to its educational and research missions.
Universities are particularly well-situated to reduce their carbon emissions and nitrogen pollution because they can both educate a community and make management decisions to reduce their impacts on the environment. Carbon and nitrogen footprints also have significant overlap, especially in the energy sector. Because of this, almost any plan to reduce a university’s carbon footprint will also reduce their nitrogen footprint. Combining the existing university carbon and nitrogen footprint tools could help universities better understand and address a broader range of their environmental impacts.

In this talk, we will first present the nitrogen challenge and how nitrogen footprints can be part of the solution. We will demonstrate the university-level nitrogen footprint tool and will share nitrogen footprint results for universities that are already calculating their footprint, including the University of Virginia—where this approach was piloted—and the University of New Hampshire. Finally, we will explain how the carbon and nitrogen footprint overlap and we will make a case for combining the UNHSI Campus Carbon Calculator and the University Nitrogen Footprint Tool into a single tool for universities.