Introduction
Composting as a Public Health Strategy
What is Composting?
Composting and Climate: Recent Policy and Global Trends
Access and Equity: Who Gets to Compost?
Call to Action
Links to Community Composting Programs, Government Resources, and Zero-Waste Guides
References
By turning kitchen scraps and yard waste into valuable compost, communities can curb deadly methane emissions, support healthier soils, and drive climate resilience, making composting a powerful public health intervention for a greener, fairer future.
Image Credit: Viktor Sergeevich / Shutterstock.com
Introduction
Nearly half of all waste is organic and compostable. When unmanaged, this waste releases methane, a powerful greenhouse gas (GHG) and potent air pollutant, that contaminates ecosystems and causes one million premature deaths annually.1,3,4,8
Composting transforms organic waste into nutrient-rich soil, offering a sustainable alternative to harmful synthetic fertilizers. Compost material also enhances soil health, biodiversity, and air quality while reducing landfill waste and pollution.
Recognizing these benefits, governments worldwide are adopting composting laws and programs, which has allowed this practice to become a growing global strategy for climate action and public health protection.1-3,5,6
Composting as a Public Health Strategy
Mismanaged organic waste in landfills produces methane, a GHG over 80 times more potent than carbon dioxide (CO2) in trapping heat in the atmosphere. The release of methane accelerates the depletion of the ozone layer and global warming, which worsens heat waves and increases the risk of contracting and severity of heat-related illnesses, asthma, and spread of vector-borne diseases like malaria.4,8
Moreover, decomposing waste generates leachate, a toxic liquid that can contaminate groundwater with heavy metals and pathogens, thus posing serious health risks, especially to nearby low-income communities. Composting minimizes leachate generation while also diverting organic waste from landfills.4,5
Organic waste in mixed trash also attracts pests such as rats and flies, which are often hosts to zoonotic diseases like leptospirosis and salmonella. Diverting organic waste by composting reduces pest populations, thereby lowering disease transmission.
Taken together, composting is an effective waste management practice and crucial public health strategy that addresses climate impacts, water safety, and disease prevention to build healthier and more sustainable communities.7
What is Composting?
Composting is a controlled, primarily aerobic, natural decomposition process during which organic waste, such as food scraps, yard trimmings, and paper, is broken down by microorganisms into a nutrient-rich, stable, carbon-rich substance called humus.
These microbes include bacteria like Gamma-Proteobacteria and Bacteroidetes, as well as fungi such as Actinomycetes, Phycomycetes, and Ascomycota. Trichoderma harzianum is used commercially in countries like China to improve plant health through its interactions with soil and roots. In some systems, earthworms stabilize organic residues through a process known as vermicomposting.2-7
Composting generates a valuable resource from food waste that improves soil fertility and fosters a healthier soil microbiome. Composting also enriches soil with essential nutrients like nitrogen, phosphorus, and potassium (NPK), while supporting soil biodiversity and microbial activity. The resulting improvements in soil structure and organic carbon content help prevent erosion, retain moisture, and reduce reliance on chemical fertilizers, all of which are vital for long-term soil and food system health.4
Successful composting relies on a mixture of nitrogen-rich materials like vegetable peels, coffee grounds, and grass clippings, as well as carbon-rich brown materials such as dried leaves, paper, and wood chips. Importantly, pet waste, plastics, polythene bags, dairy, meat scraps, oily foods, diseased plants, and chemically treated yard waste can attract pests or introduce harmful pathogens and pollutants.3,4
Composting also serves urban environments in transformative ways, as it enhances the quality of green infrastructure like rain gardens, parks, and community farms. Moreover, composting can be used to cool urban heat islands, improve air quality, and support food security, particularly in underserved communities.
Composting supports plant life and contributes to pollution prevention, bioremediation, and plant disease control. Thus, composting is a foundational practice for soil regeneration, climate resilience, and community health.4
Composting and Climate: Recent Policy and Global Trends
Throughout the United States, cities and states are increasingly implementing aggressive composting mandates to reduce landfill-bound organic waste and prevent the excessive release of methane gas. For example, California’s Senate Bill 1383 requires a 75% reduction in organic waste disposal and 20% increase in edible food recovery by 2025.
Targeting methane, SB 1383 positions composting as a frontline strategy in the state’s climate action and drought resilience efforts. Cities like San Francisco have already diverted over 80% of their waste through mandatory composting programs, while Vermont rolled out a statewide composting mandate in 2020.
The United Nations, through agencies like the UN Environment Programme (UNEP) and Economic and Social Commission for Asia and the Pacific (ESCAP), emphasize the importance of leveraging new technologies, shifting toward plant-rich diets, and consuming alternative sources of protein to reduce GHG emissions from livestock cultivation and agricultural practices. These efforts have the potential to limit global warming to 1.5°C, which is the primary target of the Paris Agreement.8
Global recommendations include decentralized composting, separating organic waste at the source, and using static piles, aerated piles, and windrows. Appropriate mixtures of carbon- and nitrogen-rich materials, along with proper moisture, temperature, and aeration, enhance composting efficiency. Education and awareness campaigns are also encouraged to increase compost adoption globally.8
The Sixth Assessment Report published by the Intergovernmental Panel on Climate Change (IPCC) urges countries to improve waste collection, invest in composting and anaerobic digestion, as well as reduce biodegradable waste in landfills. Each of these strategies are currently being adopted in national climate plans under the Paris Agreement.9,10
Urban planners are also incorporating compost into green stormwater systems, parks, and urban farms to manage runoff, restore soil health, and cool city temperatures. Compost-enriched soils absorb more water during heavy rainfall, retain carbon, and support food production, especially in underserved communities vulnerable to both climate and health disparities.
Why is Composting Good for the Environment?
Access and Equity: Who Gets to Compost?
Despite health and environmental benefits, composting remains inaccessible for several low-income communities. These areas often lack basic infrastructure such as curbside collection, local drop-off points, or safe spaces for home composting. Knowledge gaps, limited outreach, and language barriers further restrict participation.
The communities most vulnerable to pollution and climate impacts stand to gain the most.Community composting programs in schools, housing complexes, and urban gardens teach sustainability to reduce food waste and empower residents. School-based initiatives also integrate composting into education, nurturing environmental awareness early on.
Inclusive environmental policies are essential to make composting a truly equitable climate and public health solution. Health authorities and organizations must prioritize underserved areas for funding, provide multilingual educational support, and empower local leadership. All individuals, regardless of income or neighborhood, deserve the chance to turn waste into wellness.
Call to Action
Composting is a simple yet powerful tool to protect global climate and health. By recycling food scraps and yard waste into nutrient-rich compost, individuals can reduce landfill methane emissions, improve air and water quality, as well as support healthier, more sustainable soils and food systems.
Small efforts can yield considerable benefits such as cooling the planet, preventing disease, and reducing reliance on synthetic fertilizers. To fully realize these benefits, individuals must view food waste as a public health issue, not a nuisance. Composting is more than environmental responsibility; it’s a vital health intervention.
Now is the time to act. Start a backyard compost pile, join a local composting program, advocate for better local composting infrastructure, or use indoor composting tools. Treat composting as a public health priority and help turn everyday waste into a resource that heals communities and the planet.
Links to Community Composting Programs, Government Resources, and Zero-Waste Guides
References
- Geng Y, Cao G, Wang L, Wang S. (2019). Effects of equal chemical fertilizer substitutions with organic manure on yield, dry matter, and nitrogen uptake of spring maize and soil nitrogen distribution. PLoS One, 14(7):e0219512. DOI: 10.1371/journal.pone.0219512, https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0219512
- Ye L, Zhao X, Bao E, Li J, Zou Z, Cao K. (2020) Bio-organic fertilizer with reduced rates of chemical fertilization improves soil fertility and enhances tomato yield and quality. Sci Rep, 13;10(1):177. DOI: 10.1038/s41598-019-56954-2, https://www.nature.com/articles/s41598-019-56954-2
- Neher DA, Weicht TR, Bates ST, Leff JW, Fierer N. (2013). Changes in bacterial and fungal communities across compost recipes, preparation methods, and composting times. PLoS One, 21;8(11):e79512. DOI: 10.1371/journal.pone.0079512, https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0079512
- Modupe Stella Ayilara, Oluwaseyi Samuel Olanrewaju, Olubukola Oluranti Babalola, and Olu Odeyemi. (2020). Waste Management through Composting: Challenges and Potentials. Sustainability, 12, 4456; DOI:10.3390/su12114456, https://www.mdpi.com/2071-1050/12/11/4456
- Alejandra Cerda, Adriana Artola, Xavier Font, Raquel Barrena, Teresa Gea, Antoni Sánchez. (2018). Composting of food wastes: Status and challenges. Bioresource Technology, 248, Part A, 57-67, DOI: 10.1016/j.biortech.2017.06.133, https://www.sciencedirect.com/science/article/abs/pii/S0960852417310374
- Maria Pergola et al. (2018). Composting: The way for sustainable agriculture. Applied Soil Ecology, 123, 744-750, DOI: 10.1016/j.apsoil.2017.10.016, https://www.sciencedirect.com/science/article/abs/pii/S0929139316306928
- Kumar, S. (2010). Composting of municipal solid waste. Critical Reviews in Biotechnology, 31(2), 112–136, DOI: 10.3109/07388551.2010.492207, https://www.tandfonline.com/doi/full/10.3109/07388551.2010.492207
- Methane emissions are driving climate change. Here’s how to reduce them. UN Environment Programme, Accessed on 3 June 2025, https://www.unep.org/news-and-stories/story/methane-emissions-are-driving-climate-change-heres-how-reduce-them
- Bogner, J. et al. (2007). Waste Management In Climate Change Mitigation. Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change, Cambridge University Press, Accessed on 3 June 2025, https://www.ipcc.ch/site/assets/uploads/2018/02/ar4-wg3-chapter10-1.pdf
- Sixth Assessment Report, IPCC, Accessed on 3 June 2025, https://www.ipcc.ch/assessment-report/ar6/