A circular food system recovers nutrients from food waste via composting and returns them to farmland, reducing the need for synthetic (fossil-fuel-derived) fertilizer and methane-emitting landfill decay.
nutrients_recovered = diversion_rate × compost_efficiency × waste_mass
synthetic_input_needed = demand × (1 - fert_offset_from_compost)
landfill methane risk ∝ (1 - diversion_rate)
- Food waste diversion — fraction of discarded food routed to composting instead of landfill.
- Compost efficiency — how much of the diverted organic matter's nutrients are actually recovered as usable compost (losses occur as heat, CO2, leachate).
- Population demand — how fast food units are produced and consumed, scaling the whole loop's throughput.
- Synthetic fertilizer use — baseline reliance on external fertilizer; recovered compost nutrients reduce how much of this is actually needed.
Real-world application: municipal food-waste composting and farm-to-fork nutrient cycling (e.g. anaerobic digestion, urban compost programs) cut landfill methane emissions and synthetic fertilizer demand simultaneously.