Counting Calories? Count Your Carbon, Too

June 29, 2018

Sustainable eating is more in vogue than ever. Consumers around the world are growing increasingly concerned with where their food comes from, and how they can create both sustainable and healthful eating patterns. Considering the global food system contributes 

between 19-29 percent of total human-created greenhouse-gas emissions, this is a positive step forward for the planet. Many believe reducing the emissions created in food production is essential in limiting the effects of climate change.

If you’ve been trying to make sustainable food choices and find yourself a bit confused, you’re not at fault. Precisely calculating the total ecological impact of individual foods is enormously complicated, multifactorial, and often times, incident- and location-specific. Currently, the scientific community does not have precise measurement tools required to count the total impact a food has in terms of water, carbon, nitrogen, transportation, pesticide residue, consumer transport, storage, preparation, waste, and other factors.

That said, scientists have been able to come up with precise formulas to estimate average carbon emissions of certain foods. By comparing the carbon emissions produced (on average) to calories of five different meals, it becomes quite clear that certain foods and dietary patterns are more sustainable than others. Below you’ll also find a list of the carbon emissions created by some common foods, compared to calories. Some things on the list may surprise you. Keep in mind, however, that carbon emissions are dependent on season, growing location, transportation, storage, and other factors, and that these calculations do not assume any wasted food, so take these meals with a grain of salt.

Graphics by Katherine Baker

Meal #1: Bacon cheeseburger with oven-fried potatoes
Total carbon dioxide emissions: 7.5 Kg 

Meal #2: Vegetarian omelette
Total carbon dioxide emissions: 1.9 Kg

Meal #3: Salmon fillet with rice and vegetables
Total carbon dioxide emissions: 2.91 Kg

Meal #4: Vegan Buddha bowl
Total carbon dioxide emissions: 0.759 Kg

Meal #5: Peanut butter & banana sandwich
Total carbon dioxide emissions: 0.36 Kg

Even with precise carbon food production calculations, exact emissions for a particular food product depend on production methods, transportation, energy dispensed by consumers for transportation, and energy required to store and cook food (i.e., frozen foods have a higher carbon footprint). Additionally, packaging metrics vary greatly, as do production processes between and within countries. Seasonality can also impact a food product carbon footprint, with out-of-season production typically emitting greater amounts of carbon. 

Although it is at present still difficult to estimate exactly how eco-friendly your meals are, there are certain widely accepted trends that have emerged from the literature that you can use to make sustainable food choices.

Meats and cheeses emit large amounts of carbon so cutting back on certain animal products can help lower your carbon footprint. Moreover, eating as locally and seasonably as possible can reduce addition emissions. And beyond the choice of the food itself, recycling food packaging and limiting food waste whenever possible can help you strive closer to carbon neutrality. But you don’t have to change your whole eating routine overnight to make a difference. Integrating small changes into your daily life can contribute to a large impact over time.

This article by Katherine Baker originally appeared Planet Forward, a project of the Center for Innovative Media at the George Washington University School of Media and Public Affairs. Katherine Baker is an MPH candidate in Environmental Health Sciences at the Mailman School.