Energy for food produces large amounts of greenhouse gases, we need to tackle this

This week, families will gather (virtually) for holiday meals. And while there has been increasing attention paid to the greenhouse gas (GHG) emissions produced by red meat, holiday turkey also produces emissions — and so do fish, vegetables, sodas, chocolate and all the rest of what we eat, drink, or all too often waste because all this food requires energy. This energy use for food produces more GHG emissions than all of agriculture, deforestation and other land-use changes combined. Yet, it is a topic that has received surprisingly little attention and must be better managed to achieve our climate goals. 

The Food and Agriculture Organization (FAO) finds that, worldwide, food accounts for 30 percent of energy consumption, which roughly translates into emissions of over 10 gigatons of carbon dioxide equivalent.

In the U.S., the world’s second-largest GHG emitter, the Department of Agriculture (USDA) estimates that nearly 13 percent of national energy consumption is for food.

In both cases, the GHGs attributable to energy for food are substantially higher than emissions from agriculture and land-use changes combined. And while many commentators conjure up images of burping cows producing methane, a potent GHG, and argue for vegetarianism, red meat is not the only food fueling global warming. Fish, vegetables, beverages, etc. are also important because of the energy they require. 

Why does food have such large energy and carbon footprint? To answer this question, it helps to come back to the holiday turkey. First, it had to be fed, then slaughtered, plucked, processed, packaged, transported to the supermarket to be picked up, taken home and cooked. The leftovers were refrigerated, and the rest were disposed of by the local trash company.  

Energy is used in every step. And the same is largely true for the vegetables that accompanied the turkey and for the rest of the meal. According to the USDA, about one-third of the energy used in the U.S. for food is for farm production/ processing, a seventh for packaging/transport, one quarter for wholesale/retail and food services, and finally, one third by households (including food preparation). 

But there are ways to lower emissions at each step. For example, using electric vehicles reduces the transport emissions of agri-businesses and households, while improving energy efficiency in food production and preparation (including in the home) reduces energy use. Understanding where and how energy is being used for food helps identify opportunities to reduce emissions. Food waste is another area, one that has been receiving increasing attention. The FAO reports that about 11 percent of global energy demand, which generates over 3 GtCO2-eq in emissions, is used for food that is never consumed. Reducing this waste can reduce emissions.  

Time is of the essence to get a handle on energy-for-food emissions. But the world is changing fast. Population growth is driving up the demand for food, and rising affluence across the developing world is changing diets, including increased consumption of meat, processed foods and beverages.

Back in the 1980s, Peking Duck and other meats were a rarity in China’s restaurants (as were cars on the streets). Thirty years later, big yellow ducks advertising the specialty are everywhere in the capital, and per capita, meat consumption has more than doubled. Ducks may not burp methane, but the amount of energy needed to make Peking Duck differs from rice and vegetables. 

Consumer preferences are also changing in advanced economies like the U.S. In addition to vegetarianism, organic products and locally produced fruits and vegetables are gaining favor among consumers. But local produce doesn’t necessarily require less energy or produce fewer emissions than processed foods, in part because fresh fruits and vegetables spoil faster than canned products.

The food supply chain is complex. Similarly, the intricacies of food-related energy use and emissions remain poorly understood. What innovation can we expect in production and elsewhere in the food value chain? What will be the impact of these innovations on the carbon footprints of energy-for-food? How do demographic shifts and changing consumer preferences affect food demand and, in turn, energy use and emissions? How will urbanization and climate change impact food production, transport requirements and trade? Will food delivery services become the norm? And perhaps, most importantly for the climate effort, what opportunities are there to delink food from energy emissions? These are just some of the questions to which we need better answers.  

When it comes to climate change, cow burps matter, but overall energy use for food matters more. Getting to net-zero emissions, whether in 30 or 40 years, will mean decarbonizing the energy used in feeding a world population of 9 billion people.  

Unfortunately, to date, much of our information on this topic comes from a handful of studies and imperfect data. Our climate goals will be unattainable without a better understanding of this energy-for-food dynamic and what we can do about its carbon footprint. To tackle this problem, we must see a more concerted and coordinated research effort by leading food, climate and energy agencies and think tanks that explore what the future world of energy for food may look like and proposes low-carbon solutions.

 Philippe Benoit and Antoine Halff are adjunct senior research scholars at Columbia University’s Center on Global Energy Policy and were previously Division Heads (Energy Environment and Oil Markets, respectively) at the International Energy Agency.