Geographic versus institutional drivers of nitrogen footprints: a comparison of two urban universities
| Autor: | Brian E. Robinson, Max Émile Kessler-Nadeau, Sibeal McCourt, Julie Talbot, Tim R. Moore, Roxane Maranger, Kevin Manaugh, Julien Arsenault, Aidan Goertzen, Graham K. MacDonald |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Counterfactual thinking
education.field_of_study 010504 meteorology & atmospheric sciences Reactive nitrogen Renewable Energy Sustainability and the Environment Population Public Health Environmental and Occupational Health Context (language use) 010501 environmental sciences 01 natural sciences 6. Clean water Agricultural economics Footprint Urban geography Geography 13. Climate action 11. Sustainability Sustainability Per capita education 0105 earth and related environmental sciences General Environmental Science |
| Zdroj: | Environmental Research Letters. 15:045008 |
| ISSN: | 1748-9326 |
| DOI: | 10.1088/1748-9326/ab70bf |
| Popis: | Excess reactive nitrogen (N) is linked to a myriad of environmental problems that carry large social costs. Nitrogen footprint tools can help institutions understand how their direct and indirect activities are associated with N release to the environment through energy use, food, and transportation. However, little is known about how geographic context shapes the environmental footprints of institutions. Defining the system boundaries over which institutions are responsible and able to control individual drivers of N footprints is also a challenge. Here, we compare and contrast the circa 2017 N footprints for two research intensive universities located in Montréal, Canada, with a combined full-time equivalent campus population of ∼83 000. Our estimate of McGill University’s N footprint (121.2 t N yr−1) is 48% greater than Université de Montréal’s (74.1 t N yr−1), which is also reflected on a per capita basis (3.3 and 1.6 kg N capita−1 yr−1, respectively). Key institutional factors that explain the differences include McGill’s larger residential and international student populations, research farm, and characteristics of its on-campus fuel use. We use a series of counterfactual scenarios to test how shared urban geographic context factors lead to an effective reduction of the N footprints at both universities: the relatively small direct role of both institutions in food intake on campus (29%–68% reduction compared to a counterfactual scenario), energy from hydroelectricity (17%–21% reduction), and minimal car commuting by students (2%–3% reduction). In contrast, the near-zero N removal from the municipal wastewater system effectively increases the N footprints (11%–13% increase compared to a modest N removal and offset scenario). Our findings suggest that a shared geographic context of a dense city with plentiful off-campus housing, food options, and access to hydroelectricity shapes the absolute N footprints of Montréal’s two main universities more than the divergent institutional characteristics that influence their relative N footprints. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|