Environmental Benefits of Composting

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Composting benefits the environment in many ways. When you compost your food scraps, you produce a nutrient rich soil that is needed to maintain healthy and productive farm fields. This closes an important loop and completes the cycle necessary to grow more healthy food. When it comes to global warming, composting directly reduces carbon dioxide (CO2) and other powerful greenhouse gases, like methane (CH4) and nitrous oxide (N2O).

Composting is an effective way to reduce greenhouse gas emissions. Many people believe that throwing food scraps and paper products into a landfill is harmless because the materials biodegrade. However, most people are surprised to learn that when these materials break down in a landfill they rot anaerobically (without oxygen) and become powerful contributors to greenhouse gas emissions. When food scraps are thrown in a landfill, the degrading material creates methane, a greenhouse gas that is 21 times more potent than carbon dioxide.

While it is true that some landfills try to capture the methane and use it as energy, many studies have shown that most of the methane gas from landfills is released before it is captured and capture rates are at most 46% in the best-case scenario (Institute for Local Self Reliance, Environmental Protection Agency). Landfills are the single largest human source of methane emissions in the world. Even with the best technology, most of the methane from landfills is released into the atmosphere.

By composting, the generation of greenhouse gases, particularly methane, is avoided. A well-run composting operation will produce negligible greenhouse gas emissions, mostly from the operation of tractors and other equipment.

Compost improves the quality of our soil and reduces the need for chemical fertilizers and pesticides. The end product of your efforts to compost food scraps and paper products is a nutrient rich soil. When this compost is used on fields it has many benefits:

• It replaces chemical fertilizers and pesticides, avoiding greenhouse gases related to their production. The application of synthetic nitrogen to fields is a significant portion of nitrous oxide (N2O) emissions. N20 is a powerful greenhouse gas, about 310 times more potent than carbon dioxide. Compost reduces the use of NO2 and other energy intensive fertilizers and pesticides. "In fact, a single 40-pound bag contains the equivalent of 2.5 gallons of gasoline. In addition to their oil base, synthetic fertilizers are spiked with concentrated forms of nitrogen and phosphorus, which are harder for plants to absorb than their naturally occurring counterparts. The excess phosphorus and nitrogen not absorbed by plants runs off into storm drains that feed into rivers and streams, contributing to algae blooms that deprive waterways of oxygen and kill off aquatic life." From the Green Guide, National Geographic http://www.thegreenguide.com/products/print_pr.mhtml?id=308
• It improves tilth and workability of soils, resulting in less fuel consumption to till the soil.
• It helps soils hold or sequester carbon dioxide.

In addition to significantly reducing the production of greenhouse gas emissions, compost replenishes and revitalizes exhausted farm soils by replacing trace minerals and organic material, reduces soil erosion and helps prevent storm water runoff.

Not all composting is the same….there is no place like home to compost. Composting your materials at home in your backyard or right at the source are the best ways to get the most environmental benefits from composting. Collecting and hauling compostable materials, and processing them at a facility, requires fuel and energy. How much this offsets the environmental benefits of composting can only be calculated using the specifics of a particular program. However, that said, the overall environmental benefits of composting compared to the alternatives of burning or burying compostable material as waste are far superior.

Compost collection is an excellent supplement for at-the-source composting and allows for more materials to make their way from the waste stream into soil. For people who cannot compost at home (because they have limited space or no yard, for example) curbside composting provides the opportunity for them to compost, too. Composting on-site at businesses is rarely feasible, so compost collection provides a way for restaurants and grocers to reap the environmental benefits of composting. Large scale commercial composting facilities are carefully monitored and can handle materials that we would not easily compost in a backyard compost pile. For example, sustained high temperatures allow for the safe composting of meat and dairy products, as well as non-recyclable food packaging like waxed boxes, egg cartons, cotton balls, paper plates, and more.

Quantifying the environmental benefits of composting. Eureka Recycling has worked closely with the Center for Energy and the Environment to quantify the environmental benefits of both recycling and composting using the most recent research and analysis available about the life cycle of composting. These benefits have been posted on the Minnesota Energy Challenge website so you can calculate the benefits of your efforts to recycle and compost.

For more information about the environmental benefits of composting, please contact Eureka Recycling at 651-222-7678 or www.eurekarecycling.org