Make Composting Your Next Sustainable Project

Dinner clean-up just became a bit more complicated in California. As of January 1, 2022, residents in California are required to compost food waste as part of the state's strategy in reducing greenhouse emissions.

California is the second state, after Vermont, to prohibit residents from tossing food scraps into the trash. Organic waste in landfills emits 20% of the state's methane, a pollutant 84 times more potent than carbon dioxide, according to the California Department of Resources Recycling and Recovery.

Lawmakers hope this new mandate will cut down on the pollutants that contribute to the climate crises Californians experience firsthand. Compost also significantly improves contaminated soil and enhances water retention in soil, which can increase crop yields and aid reforestation efforts.

Methane is a greenhouse gas that comes from livestock, natural gas, and landfills. At the 2021 United Nations Climate Change Conference, more than 100 countries signed a pledge to reduce methane emissions at least 30% by 2030.

"Food scraps are going to break down either way, whether they're composted or in a landfill," Natalie Hoidal, MS, a vegetable and local foods educator at the University of Minnesota, told Verywell that food scraps are going to decompose whether they've been composted or gone to a landfill. But landfills account for around 15% of human-related methane emissions—the third-largest source—in the United States.

"Landfills are more likely to be anaerobic environments, so places where oxygen is limiting," Hoidal said. "Under those conditions, you're more likely to get methane as the output versus carbon dioxide."

Whether you live in an area that mandates organic recycling or you have a personal goal to start composting this year, getting started is easier than it seems.

"It doesn’t have to be expensive or fancy, anyone can compost," Hoidal said.

How Do You Start Composting?

Hoidal explained that composting is "the breakdown of organic materials into a more stable form."

The term "compost" can refer both to the actual breakdown process and the final product, she said. This broken-down organic matter provide nutrients, such as nitrogen and potassium, for the soil.

However, the amount and type of nutrients may depend on the materials used to make the compost. It can also take a few years for compost to actually add these nutrients to the soil.

To start composting, think about the space and resources you have. Look into your community's composting options. Some areas offer curbside compost pickup and others have sites where you can drop off food scraps weekly.

For an indoor system, find a container with a lid that you can keep on your counter, fridge, or freezer. There are plenty of compost bins online, but you can use a recycled plastic container or even a brown paper bag. If you plan to bring your compost to a community drop-off site, double-check to confirm what materials are accepted before you start adding to your compost bin.

If you have an outdoor space for composting, first decide where to keep your organic waste. The Environmental Protection Agency (EPA) recommends a "dry, shady spot near a water source" for composting. Once you've found the location, decide if you want to build a pile or use a bin. Consider using pallets or wire to create a fence around your pile.

Depending on where you live, a bin with a lid may be the best option to keep animals out of your compost. You can purchase an outdoor compost bin or build your own container. A large plastic bucket, garbage can, or bin could work. Be sure to drill a few holes in the bottom to allow for drainage.

"One of the best systems is to have multiple piles. You can add things to one pile, when that pile starts to get full leave it alone and start adding to your next pile," Hoidal said. "If you're constantly adding new material it's hard to get to a point where it's all broken down."

It's important to turn the compost pile every couple of weeks, she added. Unlike in a landfill, aerated compost piles have enough oxygen so they don't produce high amounts of methane. You can purchase a rotating composting bin that you can crank by hand to aerate the pile. Otherwise, use a pitchfork or shovel to turn over the pile.

A successful outdoor compost system needs green and brown organic materials, air (from rotating the pile), and water. Organic materials that can be composted are grouped into two categories: green and brown materials.

"There's no perfect compost system, but typically you want about three parts brown materials to one part green," Hoidal said.

Once you add green and brown materials to your pile, mix in some water to keep everything moist. Use the "squeeze test" to determine the right amount of moisture. Experts say compost piles should be about 60% moisture. To test your compost pile, grab a handful of the organic material and squeeze. Ideally, just a few drops of water will come out. If your pile seems too wet, add in more brown materials. And add more water if the pile seemed too dry.

Moisture helps the organic materials break down. However, the entire process of creating usable fertilizer out of compost for a garden can take anywhere from two months to two years.

Does an At-Home Compost Pile Really Make a Difference?

While one at-home compost bin might not solve the climate crisis, experts say it can make a difference.

"If you do it well, certainly. Especially if you don’t have municipal collection and composting available," Sally Brown, PhD, a research professor with the University of Washington's School of Environmental and Forest Sciences, told Verywell.

Seattle, Washington has required organic recycling for decades. Starting in 1988, the city prohibited yard waste to be thrown away. In 2015, the city started to require residents to keep food scraps out of the garbage.

When Seattle launched its composting program to include food waste in addition to yard trimmings, Brown said, some residents were concerned that the piles would attract rats. But it didn't happen.

For an at-home compost system to make a difference, composting tools and educational materials should be more accessible. Food companies could also help facilitate change by using compost-friendly materials.

Brown suggested that improving food containers and packaging would make it easier for people to develop the habit of composting, such as removing the non-compostable stickers on produce.

Composting, even small-scale piles or bins, keeps organic materials out of landfills and helps reduce greenhouse gas emissions. According to the EPA, Americans composted 25 million tons of waste in 2018. Composting, along with recycling and other landfill alternatives saved over "193 million metric tons of carbon dioxide equivalent." The EPA said this is similar to removing "42 million cars off the road in a year."

"Reducing [methane] emissions now buys us more time for the more drastic changes that need to take place," Brown said.