Composting

Mindset of Change

Most people probably know what composting is: the practice of decomposing organic scraps from your kitchen or backyard and using it as fertilizer. However, you are probably less aware of why it matters so much for the climate...and also our health.

Why composting matters for the climate

Whenever organic matter decomposes, it creates two types of greenhouse gases - carbon dioxide (CO2) and methane (CH4). This is normal. However, the ratio of methane to carbon dioxide created can vary greatly, and methane's Global Warming Potential (GWP) is about 28-36 times as high as carbon dioxide. In essence, methane heats up the atmosphere much faster.

The ratio of methane to carbon dioxide created by decomposing matter depends on how much oxygen is available while it breaks down. This is called aerobic (with oxygen) vs anaerobic (without oxygen) composting. When organic matter breaks down in the presence of oxygen, it produces primarily carbon dioxide. When it decomposes without oxygen, it produces more methane (nature.com).

When organic matter breaks down in a forest, or at the side of the road, or in your backyard compost heap, it has oxygen. Thus, it produces less methane and warms the planet less. But when it breaks down in a landfill (where it goes when you throw it in the trash), it's buried under tons and tons of other trash, especially plastic (like your trash bags), where it can't get oxygen. Thus, it produces a lot of methane and warms the planet more. This is especially relevant, because in the US approximately 50% of trash is compostable material that will create methane in a landfill.

Why it matters for our health

Our food has a nutrition problem. Although most fruits, vegetables, and grains look bigger and better than ever, on average they have 25-50% less nutrients than they did 70 years ago. That means on average we have to eat more (and more varied) foods to get the same amount of protein and essential vitamins and minerals (nationalgeographic.co.uk).

Among others, one of "the principal causes of the nutrient decline [is] the degradation of the soil in which crops are grown..." (Foods, 2024, Bhardwaj et al). While many things have contributed to the degraded quality of the soil – especially mono-crop agriculture (growing the same thing over and over again in the same soil) and relying on chemical fertilizers to compensate – a big one is that we don't return the nutrients taken from the soil.

This is where composting comes in. By composting our food scraps and using it to rebuild soil health, we are returning nutrients back to the soil. This makes our food more nutritious in turn. Also, its essentially free fertilizer for home gardeners.

Starting to compost

Now, composting may sound like a no brainer, but unfortunately, it's not always so easy. If you're lucky enough to live in a state where municipal composting is widely available and free, hurray! all you have to do is use it diligently! If you don't, well then, its time to consider your options.

1. If you have a backyard or outdoor space to do so, you can compost at home. This does have some restrictions (or at least some complications) in terms of the kind of food scraps you can safely use, but it's a pretty easy option. Checkout mindbodygreen.com for a setup guide.
   1. And when you're ready for the next level, check out vermicomposting or bokashi - not for the faint of heart.
2. If you don't have a backyard, then no worries! You still got options:
   1. See if there is a community garden or neighbor's bin that you can use near you. MakeSoil is a good way to find these composting sites!
   2. Use a paid compost service. Now, I know it seems mighty unfair to have to pay to do a good deed, but some of these services also have soil exchange programs for your window flower bed or potted herbs! And many of them contribute to local agriculture, which contributes to better nutrition. Check out some options at Litterless or GoodStartPackaging.
   3. Use an indoor composting machine. This one ranks last on my list because a lot of indoor composters don't actually create compost (they just freeze dry your food scraps) and/or require you to ship the scraps to them to be composted (adding carbon emissions). They also tend to be pretty expensive. But, a lot of people really like them! Check out the cream of the crop on Wired.
3. Or, you could try multiple options! I have both an at-home compost bin and a composting service (mostly because my compost bin freezes over in winter). My composting service also partners with my CSA for full cycle community agriculture - shout out to Urban Canopy!

A few tips

1. When in doubt about what you can compost, stick to just plant-based scraps. Health of the compost heap largely depends on the ratio of composted materials (plus microbes). Most often this is referred to as the ratio of browns (yard scraps) and greens (food scraps). Meat, dairy, clothing, wet wipes, bio-plastics etc. tend to be finicky. Some things (like bioplastics) are compostable only in certain types of municipal composting facilities. Some things (like meat and dairy) only with vermicomposting or bokashi at home. And some (like wet wipes and clothing) depend on the composition of the item and also how much of it is going into a batch of compost. When you're first starting, take it easy on yourself. Vegetable scraps and yard scraps are a good place to start.
2. If pests (ants, cockroaches, rats) are a problem in your neighborhood, consider freezing your compost. I actually freeze all my good vegetable scraps for stock anyway before they go into the compost. This serves to keep them non smelly and safe from my pests (cats).
3. Compost actually shouldn't be super smelly. Although there can be a shift in smell when you add new stuff - especially if you are incorporating bokashi or some dairy - overall, it should smell like rich dirt. If it doesn't, check out this compost guide to adjust your ratios.
4. Turn the compost! Remember, healthy compost needs air, so make sure you turn it.
5. Consider the bin! Some composting bins (like mine) are barrels that are easy to turn, so if you don't feel like shoveling, I suggest putting a little upfront thought into your bin! Also, consider the location for optimum accessibility.
6. When cooking, get out a big bowl to put all your vegetable scraps into. Then take the bowl to the bin. Save yourself some time and keep a clean cutting board!

Happy composting!

If you're a home gardener too, check out one of my favorite compost / garden techniques - the hugelkulture!