Waste Not, Warm Not: Cutting Emissions by Curtailing Wasted Food
According to the Food and Agriculture Organization and the UN Environment Programme, about one third of all food produced globally is wasted. About 13% is wasted before consumption: rotting or spoiling on farms, in unrefrigerated trucks, and during food processing. Another 19% is wasted when stores, restaurants, and consumers throw food away.
Humanity wastes more than one third of the food we produce — and with it, a huge portion of our emissions budget. From farm to fridge to landfill, uneaten food is responsible for roughly 10% of global greenhouse gases, or five times the emissions of the entire aviation sector. It also squanders land, water, energy, and labor. And as food demand rises, so will the climate cost of waste. Here’s the core challenge for innovators: It’s now cheaper to waste food than to save it. That calculus needs to change. Preventing spoilage and improving logistics must become more profitable than overproducing. The most promising solutions lie in smarter harvesting, advanced preservation technologies, and circular systems that turn waste into value. On the journey to a net-zero world, reducing food waste is low-hanging fruit.
Using IPCC and GCAM data, Energy Innovation projected future “greenhouse gas emissions at stake” in 2050, assuming current policies remain in place. The resulting estimates overlap because different technologies may reduce the same emissions pool.
The Path We’re On
Wasted food is warming the world
The amount of food that’s discarded each year is staggering: 1.3 billion metric tons. That’s enough to feed 2 billion people for a year — or fill 110 million garbage trucks.
In other words, we make more food than we need. We just waste loads of it — a fact that’s difficult to stomach, given that more than 2 billion people worldwide face some degree of food insecurity. To make matters worse: All that waste carries massive consequences for the climate.
38% of the food produced in the United States goes unsold or uneaten.
Where do food waste emissions come from?
Problem 1: We waste energy and emissions producing food we don’t eat
Lots of energy goes into producing our food — which means lots of greenhouse gas emissions. We clear forests, we use fertilizers, we burn fossil fuels to power farm equipment and transportation. Packaging our food requires paper and plastics — and generates still more emissions.
These upstream resources and energy are especially hard to justify when so much of the food that’s produced ends up wasted. Where the waste happens varies by region. In much of the Global South, food is lost early on; it spoils during harvest, storage, and transport due to heat, pests, and lack of refrigeration. In the Global North, food is lost later in its life cycle. It expires on grocery shelves, spoils in home refrigerators, and gets tossed by restaurants.
Problem 2: The food we waste produces methane
In the landfill, buried under layers of other trash, food waste compounds its climate impact. Without access to oxygen, the conditions are ripe for a process called anaerobic decomposition. As microbes break down organic matter, they produce methane (CH₄), a greenhouse gas that traps 80 times more heat than CO₂ over its first 20 years in the atmosphere.
Altogether, those tiny microbes create an enormous global problem. Landfills and other waste sources account for roughly one fifth of all human-caused methane emissions.
If we could cut food waste in half, it would amount to almost one third of the emissions cuts promised by the Global Methane Pledge for 2030.
A New Way Forward
Moving toward zero waste
The following imperatives outline the breakthroughs needed to build a more sustainable food system, one in which wasting food becomes the less economical option.
Innovation Imperatives
Reuse food, either for new human food or animal feed
Emerging technologies such as thermal processing, fungal fermentation, and insect conversion can upcycle waste streams into safe, nutritious products for people or animals. Scaling circular solutions can transform waste into value, reducing the environmental footprint of food production while closing critical loops in the food system.
Develop technology to prevent methane emissions from landfills
When organic matter like food waste is buried in landfills, it decomposes without oxygen–and so releases vast quantities of methane. This imperative focuses on deploying technologies that intercept — or even eliminate — these emissions at the source. Intercepting methane at a meaningful scale will require more efficient gas capture systems for new and existing landfills, as well as advanced oxidation or biocover technologies that destroy methane before it can escape. Better still? We could prevent methane formation altogether through anaerobic digestion, composting, rendering organics inert prior to landfilling, directly inhibiting microbial methane production, or waste-to-energy conversion. Given that landfills are such a high-concentration source of emissions, this imperative is especially cost-effective and impactful.
Innovate new ways to reduce food spoilage
Spoilage is a leading driver of global food waste. Advances in gene editing, protective surface coatings, and cold chain technology are opening new pathways to keep food fresh longer and reduce losses throughout the supply chain. Accelerating these innovations could significantly cut waste, lower costs, and boost food systems’ efficiency and resilience.
The most viable solutions will
From a climate perspective, not all food waste is equal. Solutions must address a meaningful share of wasted calories, not just expensive or fast-spoiling foods. While preserving produce can deliver economic and nutritional benefits, the largest climate impact lies in reducing the waste of staple crops and emissions-intensive meat and dairy. These are the categories that dominate global calorie production and carry the highest embedded emissions.
Waste persists because in much of today’s food system, particularly in the Global North, it can be cheaper to waste food than to save it. Solutions must change the economics in one of two ways. The first is to make waste prevention profitable. The second is to recover sufficient value from surplus and byproducts to justify the costs of logistics, storage, and processing, not to mention the hurdle of behavior change. Without a compelling financial case, adoption will stall.
Any credible solution must reduce total emissions — not shift them. That means the energy and emissions we require to prevent, process, transport, or repurpose food waste must be less in sum than the emissions we avoid by preventing methane production or release. Solutions that simply move waste around or rely on energy-intensive processing can undermine their own climate value.
