Turning Australia’s food waste into a climate solution
image: Food waste to biochar; a potential sustainable solution for Australia: a comprehensive review
Credit: Piyal Chowdhury, Tamal Chowdhury, Hemal Chowdhury & Elza Bontempi
A new review published in Carbon Research highlights an innovative way for Australia to confront its food waste crisis while cutting greenhouse gas emissions: transforming food scraps into biochar.
Each year, Australia generates roughly 31 million tonnes of food waste, costing the economy over 36 billion AUD and contributing to three percent of national greenhouse gas emissions. Most of this waste comes from food processing industries, agriculture, and households, much of it ending up in landfills where it releases methane, a potent climate pollutant. Conventional waste management methods such as composting and anaerobic digestion remain limited, either by cost or land requirements.
The research team led by Piyal Chowdhury, Hemal Chowdhury, Tamal Chowdhury, and Elza Bontempi compiled and analyzed global and Australian data on food‑waste processing technologies and identified pyrolysis, a controlled heating process that converts organic material into stable, carbon‑rich biochar, as a promising alternative. “Food waste can be turned from a burden into a resource that locks carbon in soil for centuries,” said Hemal Chowdhury of the University of New South Wales.
Unlike compost, biochar is highly stable and can vastly improve Australia’s nutrient‑poor soils. Rich in carbon, biochar enhances water retention, stimulates microbial activity, and reduces reliance on chemical fertilizers that release greenhouse gases. Studies show that adding biochar to soil can increase organic carbon content by as much as 90 percent and lower emissions of methane and nitrous oxide from croplands.
Beyond farming, the study notes that biochar can serve as an ingredient in construction materials, electrode components for batteries, and adsorbents for water purification. Integrating biochar production into Australia’s circular economy can turn food waste into valuable industrial and environmental products.
However, the review also cautions that challenges remain. High moisture content in food waste complicates drying and handling, while large‑scale pyrolysis facilities are still scarce in Australia. The authors recommend policy incentives, industry investment, and research into scalable, solar‑powered pyrolysis systems to take advantage of the country’s rich renewable‑energy potential.
By pairing waste reduction with biochar technology, Australia could make significant progress toward its national goal of halving food waste by 2030. “This approach unites circular‑economy thinking with climate action,” said Elza Bontempi of the University of Brescia. “Biochar offers a tangible pathway to cleaner air, healthier soils, and a more sustainable future.”
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Journal Reference: Chowdhury, P., Chowdhury, T., Chowdhury, H. et al. Food waste to biochar; a potential sustainable solution for Australia: a comprehensive review. Carbon Res. 4, 41 (2025). https://doi.org/10.1007/s44246-025-00207-7
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About Carbon Research
The journal Carbon Research is an international multidisciplinary platform for communicating advances in fundamental and applied research on natural and engineered carbonaceous materials that are associated with ecological and environmental functions, energy generation, and global change. It is a fully Open Access (OA) journal and the Article Publishing Charges (APC) are waived until Dec 31, 2025. It is dedicated to serving as an innovative, efficient and professional platform for researchers in the field of carbon functions around the world to deliver findings from this rapidly expanding field of science. The journal is currently indexed by Scopus and Ei Compendex, and as of June 2025, the dynamic CiteScore value is 15.4.