Climate and Resources

Wasting food has an astonishingly massive greenhouse gas (GHG) footprint. This is due to the methane produced from food decaying in landfills, the resources it takes to grow, transport, cool, and cook food, and the conversion of native ecosystems to agriculture. Fortunately, it is a solvable problem that offers some "low-hanging fruit" for GHG reductions.

Cutting food waste by half in the U.S. would reduce greenhouse gas emissions by 75 million metric tons each year – the same as taking 16 million gas-powered cars off the road. It would also generate an economic return of $75 billion each year. And importantly, reducing food waste also leads to several key co-benefits that get at critical issues of climate justice, climate adaptation, water scarcity, and biodiversity loss.

food waste

GHG Emissions from Food Waste

The United Nations estimates that if global food loss and waste were a country, it would rank third in the world for GHG emissions after the U.S. and China. In the U.S. alone, an estimated 35% of all food ends up unsold or uneaten each year, and its production, transport, storage, preparation, and ultimate disposal produce more greenhouse gas emissions than 42 coal-fired power plants. That magnitude of emissions is hard to comprehend, but understanding the GHG footprint of food loss and waste becomes easier when we take a life-cycle view of food’s journey through the supply chain.

GHG emissions

The emissions produced at each stage of the food system vary, and they add up as food progresses from farm to fork to disposal. Notably, preventing food from going unsold or uneaten is a far more impactful climate solution than recycling food scraps through compost or anaerobic digestion–when food is composted, it still uses all of the resources to produce it, whereas preventing surplus food can fundamentally reduce demand. (This follows the guidance provided by EPA’s Food Recovery Hierarchy.)

Farm

Carbon Dioxide: Land use and land use change | Fertilizer, pesticides, herbicides | Pumping water | Fuel for machinery

Methane: Land use and land use change | Enteric emissions | Manure management

Manufacturing

Carbon Dioxide: Transportation | Energy for heating, power | Water

Fluorinated Gases: Chilling

Consumer-Facing Businesses

Carbon Dioxide: Transportation | Energy for heating, power

Fluorinated Gases: Chilling

Homes

Carbon Dioxide: Transportation to home | Energy for refrigeration, freezing, washing, cooking

Donation

Emissions: Transportation to food bank 

Offsets: Avoided food production

Industrial Uses

Emissions: Processing and transportation

Offsets: Avoided fuel or feed production

Animal Feed

Emissions: Processing and transportation

Offsets: Avoided feed production

Anaerobic Digestion

Emissions: Collection and transport to digester | Process Energy | Fugitive emissions during digestion | Transport to and emissions at site of digestated application

Offsets: Fertilizer offset | Energy capture | Soil carbon storage

Compost

Emissions: Collection and transport to facility | Fugitive emissions during decomposition | Transport to and emissions at site of compost application 

Offsets: Fertilizer offset | Soil carbon storage or land productivity benefit

Land Application

Emissions: Fugitive emissions during decomposition | Transport to and emissions at site of compost application 

Offsets: Fertilizer offset | Soil carbon storage or land productivity benefit

Sewer

Emissions: Energy to grind in sink | Energy to operate wastewater treatment plant 

Offsets: Energy capture (not common in US)

Incineration

Emissions: Collection and transport to facility | Process energy for operation | Combustion emissions 

Offsets: Energy capture (often heat to electricity)

Landfill

Emissions: Collection and transport to facility | Fuel to operate machinery | Decomposition emissions 

Offsets: Energy capture (some landfills) | Soil carbon storage (sometimes included)

The Methane Opportunity

Recently, the global community has lasered in on methane (CH4) as a way to slash emissions within a more shortened time frame. Methane is a powerful greenhouse gas - 80 times more potent than carbon dioxide on a 20-year time frame. The IPCC reports that methane concentrations have increased rapidly since 2007, largely driven by fossil fuels and agriculture sectors. However, methane has a relatively short residence time in the atmosphere - it breaks down after about 12 years on average. Therefore, targeting methane sources now will reduce atmospheric GHG concentrations with effects that will be felt in just a decade or two - which is critical for limiting warming by 2050.

 

methane chart
landfill

Municipal solid waste (MSW) landfills represent the third largest source of methane emissions in the United States, accounting for 15% of US methane emissions in 2019. Food waste is the number one material in our landfills–EPA estimates that in 2018, food scraps represented 24% of material sent to landfill – and the main contributor to methane emissions produced from the decomposition of organic matter (food, yard trimmings, etc.) in solid waste under anaerobic conditions. ReFED’s analysis shows that 27.6 million tons of surplus food were sent to landfill in 2019, translating to 5.5 million tons of CO2e produced from landfill, a significant portion of which are methane. EPA research indicates that diverting food waste from landfill reduces the methane generation potential by 33%.

Beyond landfill methane, reducing the amount of meat and dairy wasted could also serve to reduce livestock-related methane emissions. Together, enteric fermentation and manure management made up 36% of US methane emissions, making agriculture the largest contributing sector. Currently, about 12% of beef, 16% of pork,  and 17% of dairy products go uneaten. Reducing waste of these products could reduce demand pressures, ultimately leading to less overproduction and lower methane emissions along with that.

Emissions from surplus food can be categorized in the following framework:

Top Food Waste Solutions for Reducing GHG Emissions

The good news is that the problem of food waste is eminently solvable – multiple solutions already exist, and many of them are "shovel-ready," just needing implementation rather than invention to reap big benefits. ReFED's analysis identified the ten food waste solutions most effective at reducing greenhouse gases, shown here:

chart

You can see the GHG emissions reduction potential of more food waste solutions in the Solutions Database from the ReFED Insights Engine.

View Solutions

Impact Resources

Roadmap 2030

Roadmap to 2030

Food waste is a systemwide problem, and solving it will require a systemwide response. Our Roadmap to 2030: Reducing U.S. Food Waste by 50% looks at the entire food supply chain and identifies seven key action areas to help guide the food system’s efforts over the next ten years. In line with the "Target-Measure-Act" framework for food waste reduction that’s been adopted around the world, the Roadmap to 2030 is a critical blueprint to help the food system take action. View the entire report on this website or download our "at-a-glance" version with key highlights.

Download Roadmap At-A-Glance PDF

Links

The Latest Food Waste News Straight to your Mailbox

Subscribe to our Mailing List

Sign up to receive periodic updates from ReFED