Comparing Institution Nitrogen Footprints: Metrics for Assessing and Tracking Environmental Impact

Institutional nitrogen footprint: Quantification of the nitrogen footprint of a Spanish Research Center

Reactive nitrogen (N) emissions can lead to severe environmental and human damages. To quantify these reactive N emissions the Nitrogen Footprint (NF) can serve as a valuable indicator. This work is the first attempt to quantify an institutional NF in Spain and the first institutional NF of a research center. The NF of the Spanish research center of INIA was quantified for the year 2019 taking into account all N emission sources. The total NF of the research center INIA for 2019 was 9289 kg N and its NF per capita is 16.1 kg N per full-time equivalent population. The largest N emission sources were food (57%) and utilities (33%), while the least N loss was fertilization for groundskeeping (0.01%), and research plots (0.15%). Taking the NF of INIA as baseline the following strategies of N mitigation were analyzed: (1) beef replacement in the menu, (2) reduction of meat by non-meat sources, (3) reduction of beef, fish, and seafood by other protein sources, (4) improving the wastewater treatment efficiency, and (5) recycling food waste. This institutional NF approach serves INIA's institution as an indicator to quantify its N pollution and allows the identification of useful mitigation strategies to reduce the overall NF.

An Integrated Tool for Calculating and Reducing Institution Carbon and Nitrogen Footprints

The development of nitrogen footprint tools has allowed a range of entities to calculate and reduce their contribution to nitrogen pollution, but these tools represent just one aspect of environmental pollution. For example, institutions have been calculating their carbon footprints to track and manage their greenhouse gas emissions for over a decade. This article introduces an integrated tool that institutions can use to calculate, track, and manage their nitrogen and carbon footprints together. It presents the methodology for the combined tool, describes several metrics for comparing institution nitrogen and carbon footprint results, and discusses management strategies that reduce both the nitrogen and carbon footprints. The data requirements for the two tools overlap substantially, although integrating the two tools does necessitate the calculation of the carbon footprint of food. Comparison results for five institutions suggest that the institution nitrogen and carbon footprints correlate strongly, especially in the utilities and food sectors. Scenario analyses indicate benefits to both footprints from a range of utilities and food footprint reduction strategies. Integrating these two footprints into a single tool will account for a broader range of environmental impacts, reduce data entry and analysis, and promote integrated management of institutional sustainability.

Assessing the Social and Environmental Costs of Institution Nitrogen Footprints

This article estimates the damage costs associated with the institutional nitrogen (N) footprint and explores how this information could be used to create more sustainable institutions. Potential damages associated with the release of nitrogen oxides (NOx), ammonia (NH₃), and nitrous oxide (N₂O) to air and release of nitrogen to water were estimated using existing values and a cost per unit of nitrogen approach. These damage cost values were then applied to two universities. Annual potential damage costs to human health, agriculture, and natural ecosystems associated with the N footprint of institutions were $11.0 million (2014) at the University of Virginia (UVA) and $3.04 million at the University of New Hampshire (UNH). Costs associated with the release of nitrogen oxides to human health, in particular the use of coal-derived energy, were the largest component of damage at UVA. At UNH the energy N footprint is much lower because of a landfill cogeneration source, and thus the majority of damages were associated with food production. Annual damages associated with release of nitrogen from food production were very similar at the two universities ($1.80 million vs. $1.66 million at UVA and UNH, respectively). These damages also have implications for the extent and scale at which the damages are felt. For example, impacts to human health from energy and transportation are generally larger near the power plants and roads, while impacts from food production can be distant from the campus. Making this information available to institutions and communities can improve their understanding of the damages associated with the different nitrogen forms and sources, and inform decisions about nitrogen reduction strategies.