Background/Objectives
Food systems contribute to global anthropogenic greenhouse gas emissions and climate change. Recognizing this, local governments and public institutions around the globe have committed to reducing their food systems' greenhouse gas emissions. While shifting menus towards more plant-based options and reducing the amount of meat purchased and served is a key strategy that's been established in the literature, other supply chain opportunities to reduce greenhouse gas emissions at the city level are less well understood. To better understand the food system greenhouse gas mitigation opportunities for local governments, we built a cradle-to-grave life cycle assessment of the greenhouse gas emissions for a weekly lunch served by the New York City (NYC) Department of Education High Schools in 2019. This poster will highlight this study's findings and how they may inform other institutions interested in their food-related greenhouse gas emissions.
Approach/Activities
We developed our life cycle assessment model using a standard NYC high school lunch menu from January 2019. We estimated the greenhouse gas emissions (kg CO2-eq) for the food items served this week from food production, processing, packaging, transportation, storage & preparation, serving & consumption, disposal transportation, and disposal. We estimated the greenhouse gas emissions per serving, per 100 grams, for the five NYC boroughs and all NYC public high schools. We explored the potential change in greenhouse gas emissions if three policy interventions currently enacted in NYC were fully realized.
Results/Lessons Learned
We found that, on average, the greenhouse gas emissions per serving of the food items were relatively low but impactful when scaled to all high schools in NYC. Consistent with our expectations, we observed that beef-based food items had the highest total greenhouse gas emissions, and vegetarian and poultry items had lower greenhouse gas emissions. We found that there was substantial variability in the percent that post-farmgate greenhouse gas emissions (i.e., greenhouse gas emissions that result after a food item has left the farm or processing facility) contributed to total greenhouse gas emissions. For the vegetarian item that contained no dairy or meat, post-farmgate greenhouse gas emissions accounted for 67% of total greenhouse gas emissions, and for poultry and dairy items, the post-farmgate greenhouse gas emissions were around a third of total greenhouse gas emissions. We observed that two of the interventions could significantly reduce greenhouse gas emissions, whereas the third intervention may not significantly reduce emissions. The two significant interventions, when implemented together, could reduce total greenhouse gas emissions for the food items by an average of 4 percent (3-4 percent). These findings suggest that as institutions shift towards more plant-based menus, it will be important for them to prioritize post-farmgate interventions to further reduce greenhouse gas emissions, but careful consideration and future research are needed on what interventions will be most successful.