In the recent Bloomberg View article posted at startribune.com/opinion (“Why Starbucks won’t reliably recycle your paper coffee cup” — http://tinyurl.com/kyhh4lc), the author states that “[c]omposting keeps the cups out of landfills, but it generates greenhouse gases.” Composting in fact reduces greenhouse gases.
Environmental Protection Agency and U.S. Composting Council studies conclude that aerobic composting does not contribute to CO2 emissions, the main contributor to global warming. Any emissions from aerobic composting are considered part of the natural carbon cycle.
Composting eliminates methane and nitrous oxide production. Aerobic compost creates a “sink,” helping to reduce emissions in the atmosphere by sequestering (locking up) the carbon in the soil. Composting also encourages greater microbial activity for further carbon sequestering.
It is when food scraps and paper products are thrown into landfills that they decompose anaerobically (without oxygen), creating methane, the powerful greenhouse gas with 70 times greater heat-trapping capabilities than carbon dioxide. Burning is no better. When waste is burned, incinerators emit carbon dioxide and nitrous oxide, a greenhouse gas 310 times more powerful in atmospheric warming than carbon dioxide.
A zero-waste approach is one of the fastest, cheapest and most effective strategies we can use to protect the climate and the environment. If all Americans recycled and composted, it would reduce greenhouse gases by an amount equivalent to closing one-fifth of our coal-fired plants.
Felicity Britton, Minneapolis