You are what you eat. And environmentalists know that personal dietary choices affect climate change as well as your personal health because food production accounts for nearly a quarter of greenhouse gas emissions, with animal-based foods taking a greater toll than grains, legumes, vegetables, and fruits.

Today, Harvard took its most recent step toward reducing the climate impacts of food, signing onto the Cool Food Pledge, whose signatories are committed to a group goal of slashing food-related greenhouse gas emissions by 25 percent by 2030, largely by paying attention to menu options. The decision to join this pledge builds on years of collaborative, research-driven sustainable food programming already in place across the University. And it complements a suite of University-wide initiatives aimed at making Harvard fossil fuel neutral by 2026, and fossil fuel free by 2050.

“Addressing the emissions associated with our food choices is a focal part of Harvard’s holistic approach to using our campus as a testbed to address climate change and sustainability,” said Executive Vice President Katie Lapp. “This pledge gives us a common science-based collective target and a way of learning together with institutions around the world as we strive to create a more sustainable food system.”

“Climate change is accelerating, and Americans are the greatest contributors to it because of our diets and lifestyles,” said Walter Willett, professor of epidemiology and nutrition at the T.H. Chan School of Public Health and co-chair of Harvard’s Food Standards Committee, which launched in spring. “Among the many changes we need to make, including a rapid shift to green energy, is a change in diet to a more plant-based way of eating. If we do this right, such changes will also lead to improvements in health and many other aspects of our environment. The actions of every individual are important, but because Harvard intends to be a leadership institution and educates people who will be leaders, steps such as the Cool Food Pledge can be particularly impactful.”

Harvard’s Sustainable and Healthful Food Standards, released in April, were informed by research (including the 2019 report by the EAT-Lancet Commission on Food, Planet, Health spearheaded by Willett) and by existing programs (Menus of Change and the Good Food Purchasing Program). They were developed by a multi-disciplinary faculty committee in partnership with the Office for Sustainability (OFS) with input from the Council of Student Sustainability Leaders and experts in the field. They are designed to increase access for students, faculty, staff, and visitors to sustainable and healthful food offerings, while also enhancing their food literacy, so they have a firmer grasp on the consequences of their food choices.

“Food is arguably the most personal connection between the climate issue and people’s health,” said the Food Standards Committee’s other co-chair Ari Bernstein, who is an instructor in pediatrics at Harvard Medical School, and the director of the Center for Climate, Health, and the Global Environment (C-CHANGE). “People who are concerned about climate focus on questions on what is the least carbon intensive diet, but many more people are going to want to know about the foods that promote their health right now. The good news is that they tend to be aligned.”

Harvard undergraduates and grad students are developing programs to support these food sustainability goals across campus — all as part of Harvard’s Living Lab Initiative, which encourages students, faculty, and staff to think of the campus as place to test innovative solutions to global sustainability challenges.

Junior Meaghan Townsend, a resource efficiency program student coordinator for OFS, created a plant-based eating guide to help her fellow students craft their own diets. Townsend interviewed peers about what they knew about plant-based eating, what their concerns were, and what recommendations they might have for others considering such a diet. A key takeaway: Eating a plant-based diet doesn’t have to be an all-or-nothing proposition. Choosing simply to eat less meat can have a positive impact on your health and the environment. There’s also a section in the guide on athletes who eat plant-based diets to dispel misconceptions that such food choices compromise energy or athletic performance. This point was especially important to Townsend, who rows on the College’s heavyweight crew team.