Overview
- The University of Oxford paper published Wednesday calculated that a switch to fully organic free‑range egg production would emit about 2,316,000 tonnes of CO2 a year versus 1,184,000 tonnes for caged production, a roughly 60% rise.
- On a per‑kilogram basis the study reports free‑range organic eggs generate about 3.52 kg CO2 per kg, compared with roughly 2.1–2.8 kg CO2 per kg for caged, furnished‑cage and non‑organic systems.
- The authors attribute most of the difference to feed: organic free‑range flocks require more feed per egg and organic feed crops have lower yields, making feed production the dominant source of emissions.
- The study highlights a welfare‑environment trade‑off: organic free‑range systems score better on some welfare measures but showed higher mortality (about 8%) than enriched cages (about 2.5%) and barns (about 3.5%).
- The paper uses UK farm data from 2009–2010 and the authors warn practices have changed since then, so they call for updated data and improvements in genetics, nutrition, feed supply and farm management before making policy or consumer recommendations.