How Much Climate Impact Does Composting Avoid?

Yes — there is a reasonable rough way to estimate it, but the number depends a lot on what your “yard” contains.

For a community composting program, the simplest place to start is with food scraps, because those are the materials most likely to generate methane if they go to a landfill. A practical estimate is that one cubic yard of food scraps weighs about 463 pounds (EPA estimates). Using current EPA WARM factors for composting instead of landfilling food waste, that comes out to roughly 0.15 metric tons of CO2-equivalent (CO2e) emissions avoided per cubic yard composted, or about 332 pounds CO2e per cubic yard.

So, as a rough communication number, you could say:

Each cubic yard of mostly food scraps we compost instead of sending to landfill avoids about 0.15 metric tons CO2e, or about 332 pounds CO2e.

That means:

1 cubic yard = about 0.15 metric tons CO2e avoided
10 cubic yards = about 1.5 metric tons CO2e avoided
50 cubic yards = about 7.5 metric tons CO2e avoided

For a more tangible comparison, one cubic yard of food scraps composted is roughly similar to avoiding about 375 miles of passenger vehicle driving, using EPA’s estimate that a typical passenger vehicle emits about 400 grams of CO2 per mile.

One important note: this is a rough estimate, not a full life-cycle accounting. The actual value will vary depending on what is in the pile. A cubic yard of wet food scraps is very different from a cubic yard of leaves, brush, or mixed yard waste. Composting method, moisture, aeration, and transportation also affect total emissions. Still, for a small community program, this is a solid and defensible way to communicate the climate benefit.

For your program, you can frame it like this:

“Using a rough EPA-based estimate, every cubic yard of mostly food scraps that we compost instead of landfill avoids about 0.15 metric tons of CO2-equivalent emissions. That means our program is helping reduce methane-generating waste while producing compost that improves local soil health.”

FACTS

Benefits of Composting

• Reduces methane emissions from landfills.
• Reduces waste.
• Recycles organic materials into a valuable soil amendment – compost.
• Recovers nutrients in organic materials and provides an opportunity to keep them local.
• Creates green jobs.
• Extends municipal landfill life by diverting organic materials.

Reference:

Public Comments on EPA's Waste Reduction Model (WARM) | Institute for Local Self-Reliance - ILSR, accessed March 8, 2026, https://ilsr.org/article/composting-for-community/public-comments-on-epas-warm/

How the US Economy and Environment can Both Benefit From Composting Management, accessed March 8, 2026, https://pmc.ncbi.nlm.nih.gov/articles/PMC9575438/

Using Life Cycle Analysis to Measure GHG Emissions from Composting, accessed March 8, 2026, https://compostingtechnology.com/using-life-cycle-analysis-to-measure-ghg-emissions-from-composting/

Documentation for Greenhouse Gas Emission and Energy Factors Used in the Waste Reduction Model (WARM) - EPA, accessed March 8, 2026, https://www.epa.gov/sites/default/files/2016-03/documents/warm_v14_organic_materials.pdf

Quantifying Methane Emissions from Landfilled Food Waste | US EPA, accessed March 8, 2026, https://www.epa.gov/land-research/quantifying-methane-emissions-landfilled-food-waste