Landfills Contribute to Global Warming

February, 2013
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Garbage is a major contributor to global warming. Solid waste landfills are the single largest man-made source of methane gas in the United States. Methane (CH4) is a powerful greenhouse gas that is 23 times more effective at trapping heat in the atmosphere than the most prevalent greenhouse gas—carbon dioxide (CO2).   The Zero Waste for Zero Warming Campaign of the Global Alliance for Incinerator Alternatives (GAIA) is organizing in communities worldwide to address waste as a primary root cause of global warming. 

According to Californians Against Waste, ton for ton, Zero Waste strategies—(1) Waste Prevention, (2) Reuse, and (3) Recycling and Composting—reduce more pollution, save more energy and reduce greenhouse gas (GHG) emissions more than any other activity.
Californians currently throw away millions of tons of recyclable materials every year. According to the California Integrated Waste Management Board, over 60 percent of the materials in California landfills could be composted or recycled.  To help prevent the public health and environmental threats posed by global warming, California has committed to an aggressive series of GHG emission reduction goals. Every sector of the state is being called upon to reduce their GHG emissions—including the waste management sector.

Zero Waste strategies reduce GHG emissions in three important ways.  First, waste prevention in product design, packaging and operations is the most effective method of reducing GHG emissions because it eliminates the extraction of virgin resources for products—especially avoiding single-use products and packaging.

Second, collecting, transporting and processing discarded materials for recycling and composting releases greenhouse gases, but has a net reduction of GHG emissions. Replacing raw material with recycled feedstock in the manufacturing of new goods dramatically reduces the energy and related emissions associated with raw material extraction processes.  Third, and the last resort of these options, is recycling and composting to divert these materials from solid waste landfills and incineration.

Landfills are designed to be anaerobic, meaning that once waste has been dumped, very little air remains below the surface. Landfill gas is generated as a byproduct of the digestion of organic materials by organisms that thrive in these anaerobic conditions. Food waste, paper, grass, and other organic matter is readily digested and turned into landfill gas, which is 50 percent methane. While most modern landfills are required to capture some of their methane emissions, significant quantities continue to escape into the atmosphere.

While new waste incineration technologies are being promoted as ‘clean and green,’ they are not the best option for generating energy and have significant GHG emissions.  In addition to air and water emissions (incineration produces carbon dioxide as a by-product), incinerators create toxic ash or slag that must then be landfilled. This ash contains heavy metals, dioxins, and other pollutants, making it too toxic to reuse, although industry often tries to do so.

Humboldt County threw away more than 110,000 tons in 2005 according to CalRecycle, the state agency that gathers waste-related data. Total greenhouse gas emissions from this waste are estimated to be over 38,000 tons of carbon dioxide.

This is equivalent to burning 149 railcars full of coal, or burning 3.9 million gallons of gasoline, every year. Nearly one third of the greenhouse gases emitted come from food waste alone, and the exhaust emitted while transporting this waste out of Humboldt County contributes about 16%. These emission estimates were provided by the Redwood Coast Energy Authority (RCEA).   With the assistance of local jurisdictions and public agencies, RCEA is developing a greenhouse gas emissions tool specific to the Humboldt County area so that future emissions can be easily quantified.

Remember, every time you throw something away, you contribute to global warming.   Your decision to be a part of the solution starts with your point-of-purchase.  Avoid single-use products and packaging; find second uses for them; recycle; and compost.  For more information about local zero waste strategies,

Margaret Gainer is the Public Education Coordinator for Zero Waste Humboldt.

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