Food scraps comprise as much as 20% of the waste sent to landfills. When packed into landfills, they decompose under anaerobic conditions — meaning in the absence of oxygen. Methane gas — a greenhouse gas with 23 times the heat–trapping capacity of carbon dioxide (CO2) — is produced when organic materials such as food scraps, lawn and garden clippings, paper, and wood decompose under anaerobic conditions. Landfills are the largest source of human created methane in the U.S.

The methane produced by food scraps in landfills is quickly released into the atmosphere. In fact, it only takes between 28 and 100 days for landfilled food scraps to release methane — and landfill gas collection systems more than likely aren't capturing it. The current regulations don't require methane gas capture systems to be installed in a new landfill cell until between 2 and 5 years after the cell has been opened. Thus, the methane gas from the food scraps is released into the atmosphere long before the collection system is required to be in place.

As a result, food scraps in landfills can significantly contribute to global warming — which makes it even more important to keep them out. For every 1 ton of food scraps separated from the trash before it gets to the landfill, the equivalent of 6 tons of carbon dioxide (CO2) is prevented from being released into the atmosphere.* Using a Green Cone decreases CO2 emissions further by eliminating the need to haul food scraps to a compost facility.

Sources:
Environmental Protection Agency, Landfill Methane Outreach Program (LMOP)
http://www.epa.gov/lmop//

Sally Brown, University of Washington
Presentation at National Recycling Coalition's Annual Congress 2007
“An Evolution in Thinking on Banana Peels, or Food Waste and Greenhouse Gas”

* Based on average values from peer–reviewed literature.