Why and how to compost: climate solutions at work
Here's a science lesson for us: When organic scraps like banana peels or coffee grounds end up in landfills, they decompose “anaerobically”— without the presence of oxygen. Anaerobic decomposition releases methane, a greenhouse gas (GHG) with a warming potential ~25-30 times more than carbon dioxide over a 100-year period, and over 80 times more over the first 20 years. In other words, the heating effect of methane is way more intense than carbon but dissipates faster.
Waste from landfills is still burned in 72 incinerators across the country. They release greenhouse gases and toxins into the air — including byproducts of medical waste — mostly in low income and BIPOC communities.
We need to stop incinerating trash, and we can also create less of it by sending organics through aerobic composting, which decomposes organic waste in the presence of oxygen. Methane is not a major byproduct. Composting is an ancient tradition that slows down the growth of our ever expanding landfills (by 28%!!) and enriches soil — which reduces reliance on artificial fertilizer. It also sequesters carbon and improves the ability of soil to hold water by 2.5 times. It is one of the many wisdoms that we lost as a result of global industrialization. But it is not gone!
“As temperatures heat up everywhere, we can all take steps to help mitigate resulting changes. Composting at the community level helps close consumption loops and do so locally, which distributes the burden of waste processing more evenly, helps our local soils by reinvigorating them with locally made compost, and helps us all think more critically about our waste at different levels.”
How do scraps become compost?
Organizations and homes set aside organics like vegetable peels, fruit peels, coffee grounds, eggshells, grass clippings, leaves, small branches from all other kinds of trash.
Scraps get to a composting center, where they might be sorted further to remove contaminants.
Large pieces of material are shredded or ground to accelerate decomposition.
Sometimes, materials like wood chips or straw are added to balance the carbon-to-nitrogen ratio that best serves decomposition. Moisture is balanced, too.
The material is piled and turned to aerate (aerobic!) its insides while still generating enough heat — about 130-160°F — to kill pathogens and weed seeds.
The compost cools and cures while it finishes decomposing. Large particles are removed.
The compost is then used for horticulture, landscaping, erosion control, land reclamation, and more.
How do we get started?
Composting is basically a no-brainer, but our systems are not yet set up to make it easy for us, and in some ways they even make it hard. If you're interested in bringing this practice into your home, start by asking the internet and your local family, friends, community centers, and grocery stores who’s collecting organic scraps. The good news is that composting is also community and policy: you'll probably get to know new people and learn more about public systems on the way.
