Today's Interactive Menu now includes symbols to indicate carbon emissions for many of the items served in the Food Gallery at Frist and in the dining halls. Based on the results of a study in which food purchases in the categories of local, organic, fair trade, humane and socially just conducted by Princeton University students as part of the PEI/Grand Challenges internship program, look for these icons to indicate a rating from high to low emissions.

Here's what the symbols mean:

Low Emissions- Green Apple
Dining options categorized as having low emissions largely encompass menu items featuring fruits, vegetables, legumes, chicken, fish, and grains. These foods generate considerably fewer emissions mostly because of much lower feed necessities and waste generated during production. As Princeton purchases much of its produce and the majority of its poultry from local vendors, transportation emissions are cut as well. For products such as fish that may travel farther distances to reach campus, Princeton works to purchase and serve seafood that is grown and caught sustainably with minimized waste production and habitat damage, lowering emissions and environmental impact.

Medium Emissions- Yellow Apple
Menu items on this list include dishes and recipes with cheese, tofu, turkey, and pork. Greenhouse gas emissions for these cheese and tofu products can largely be attributed to the energy inputs for production and processing; transportation, packing, and cooking technique also contribute to different levels of emissions. While turkey and pork have relatively lower environmental impact than beef and lamb, animal products in general have associated emissions from feed and waste.
 

High Emissions- Red Apple
This list consists mainly of beef and lamb menu items. Meals that include beef and lamb have notably high associated greenhouse gas emissions because as they are raised, the animals produce not only relatively high levels of carbon dioxide but also significant amounts of methane (a greenhouse gas with over 70 times the global warming potential as carbon dioxide, as calculated over a 20 year time horizon). A four-ounce serving of grilled streak can generate over two times as much carbon dioxide as four ounce serving of raw veggies. Princeton manages to reduce its food emissions by purchasing grass-fed beef from local vendors, providing campus dining halls and food serveries with meat from animals raised organically (thus eliminating emissions from feed treated with fertilizers or pesticides that produce greenhouse gases).