Check It Out: The Sky High Emissions of Global Food Waste… and One Way to Bring Them Down

By Aaron Whittemore, Center for Sustaining Agriculture and Natural Resources, Washington State University

By some estimates the food sector contributes to about one-third of global greenhouse emissions, which isn’t so surprising given the huge amount of energy required to grow crops, feed livestock and pack and transport food across global markets. What may be more surprising is that food waste accounts for half of those emissions. This means that about 16% or so of global greenhouse gas emissions are wasted on producing food that is never eaten, never used for any other beneficial purpose, and in many cases ends up decaying in a landfill. 

Pile of rotten apples
A pile of rotten apples, which if left unmanaged, will release greenhouse gasses and represent a missed opportunity to repurpose food waste. Credit: Unsplash, Marek Studzinski.

A study published in Nature Food led by a team from Nanjing Forestry University in China calculated emissions from food loss and waste at nine different lifecycle stages, occurring within food’s journey from farm to eventual disposal. More than 30% of emissions occur at the end-of-life stage, which is affected by how food waste is disposed of and managed. A key solution to these end-of-life stage emissions could be increasing the use of innovative technologies like anaerobic digestion, which can reduce and capture those emissions. Anaerobic digestion in particular has the added bonus of creating two valuable byproducts: biogas, which can be used as an energy source, and digestate, a nutrient rich substance which is often used as a soil amendment or further processed into other useful materials. The study found that a 50% increase in deployment of emissions-reducing waste management technologies like anaerobic digestion and composting could curtail total food waste emissions by 15%. 

Diagram of feedstocks and products of anaerobic digestion
The feedstocks and byproducts of anaerobic digestion. Credit: EPA.

To learn more about this new research, check out this blog post about the study, or read the research article firsthand (though there may be a paywall preventing free access). To learn about how states in the Pacific Northwest are striving to combat the pertinent issue of food waste, check out the Use Food Well Washington plan, and the Oregon DEQ Strategic Plan for Preventing the Wasting of Food.


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