Worked example · food

Chicken

Two pounds of edible chicken meat represents approximately:

17 lbCO₂e across cradle-to-retail supply chain
7 lbfeed input, working value
~140 galfreshwater consumption, cradle-to-farm-gate
~5.0 m²·yrland occupation, mostly feed cropland

What this means

The public unit is two pounds of edible chicken meat; the formal functional unit and boundary still control the measurement. The source literature may report chicken as live weight, carcass weight, edible weight, or retail product, so the unit matters. For the related continuous animal product, see eggs.

Formal measurement basis

Item measuredChicken meat
Formal functional unit1 kg edible chicken meat
Reader-facing unit2 pounds of edible chicken meat
Primary boundaryCradle-to-retail where available
Secondary boundaryCradle-to-farm-gate or live-weight production where source requires it
Source reviewVersion 2 source review, 2026

Full measurement table

Physical quantityWorking valueLiterature rangeUnitBoundary note
GHG emissions8.52.6–20kg CO₂e / kg edible weightCradle-to-retail chicken meat, GWP100 basis where source supports it
GHG emissions, 2-lb reader unit~17.0~5.2–40.0lb CO₂e / 2 lb edible chickenConverted from edible-weight values
Feed input~3.5Range pending hardeningkg feed / kg edible chickenDerived from commercial broiler feed conversion on live-weight basis, converted to edible weight
Feed input, 2-lb reader unit~7.0Range pending hardeninglb feed / 2 lb edible chickenReader-facing conversion
Water consumption~590Range pending broader hardeningL / kg edible chickenCradle-to-farm-gate freshwater consumption; includes feed irrigation. Converted from ~300 L / kg live weight (Beal et al. 2023 baseline) using an approximately 0.51 edible-to-live ratio
Water consumption, 2-lb reader unit~140Range pending broader hardeninggallons / 2 lb edible chickenReader-facing conversion
Land occupation~5.5Range pending broader hardeningm²·year / kg edible chickenDominated by feed cropland. Converted from 2.83 m²·year / kg live weight (Beal et al. 2023 baseline)
Land occupation, 2-lb reader unit~5.0Range pending broader hardeningm²·year / 2 lb edible chickenReader-facing conversion

What is included

The working GHG value uses a cradle-to-retail edible-weight boundary. Feed input is included as an item-specific production input because it is central to chicken production. It is not treated as a framework-level category across all items.

The water and land working values use a narrower cradle-to-farm-gate boundary from a U.S. broiler LCA: feed production and on-farm operations are included, but processing, distribution, and retail are not. The two boundaries are individually defensible under their stated system boundaries.

What is excluded

Why values vary

Chicken values vary by feed composition, production system, region, electricity source, feed conversion, mortality, processing boundary, and whether the functional unit is live weight, carcass weight, edible weight, or retail weight.

Source notes

The GHG working value uses the midpoint of a typical cradle-to-retail edible-weight range reported by WWF/Moberg. The feed-input value is plausible on an edible-weight basis but still needs a hardened range. The water and land working values are derived from Beal et al. (2023), a peer-reviewed U.S. broiler LCA in Poultry Science that reports a 2020 baseline case of 0.30 m³ (~300 L) freshwater consumption and 2.83 m²·year land occupation per kg live weight, under a cradle-to-farm-gate boundary. Values are converted to a per-kg-edible-chicken basis using an approximately 0.51 edible-to-live ratio, consistent with the feed-input conversion used elsewhere on this page. Literature ranges for water and land remain to be hardened.

Sources

  1. World Wildlife Fund / Moberg, Measuring and Mitigating GHGs: Chicken. Used for: cradle-to-retail GHG working value, GHG range, edible-weight basis, and feed-conversion explanation.
  2. Resilience Services / National Chicken Council, Broiler Production System Life Cycle Assessment: 2020 Update. Used for: U.S. broiler LCA categories, including land use, global warming, water consumption, fossil resource scarcity, and particulate matter formation.
  3. FAO, Greenhouse Gas Emissions from Pig and Chicken Supply Chains: A Global Life Cycle Assessment. Used for: poultry supply-chain methodology and global context.
  4. Beal et al., Economic and environmental assessment of U.S. broiler production: opportunities to improve sustainability, Poultry Science, 2023. Used for: cradle-to-farm-gate baseline freshwater consumption (0.30 m³ / kg live weight) and land occupation (2.83 m²·year / kg live weight) working values for U.S. broiler production.