Environmental impacts of coffee, methodological bottlenecks and practical levers

Rationale: Coffee is one of the world's most consumed beverages and traded commodities 1. Grown in the tropics and consumed globally—especially in Europe (54%) 2 —coffee is part of diverse supply chains. Meeting rising demand may require doubling production by 2050, potentially causing land use change (LUC) and contributing to biodiversity loss and climate change. Life Cycle Assessment (LCA) can assess environmental impacts, but variability in methods and data hinders clarity. This paper explores sources of variability and uncertainty in coffee LCA studies. Methods: We performed a systematic review of coffee-related LCA literature 3 using the keywords: “coffee (Topic) AND LCA OR life cycle a* (Topic).” After removing duplicates and screening for relevance, 227 documents remained, from which 39 studies were selected based on scope and methodological robustness. We analysed methods and results to identify sources of variability, uncertainty, and consistent impact drivers. Results: LCA study variability reflects both diversity in coffee systems and inconsistent data and assumptions. Median GHG emissions for coffee drinks were 8.8 CO₂eq/kg (range: 2–23); for green coffee, 3.6 CO₂eq/kg (range: 0.15– 14.5). Two key discrepancies emerged: i) LUC assessment methods and carbon stock estimates; ii) treatment of wet processing. LUC impacts are significant when forests are cleared for coffee. Agroforestry and replanting may reduce emissions through increased carbon storage, though timelines and assumptions varied. Wet processing was often omitted due to lack of data, though untreated wastewater can emit methane and significantly raise GHG. Synthetic fertilisers are a major driver of various impacts. Organic alternatives may reduce impacts, but outcomes depend on their source and composting emissions. Recycling residues like husks near farms can help, but composting impacts must be accounted for. Many studies lacked quantitative data on organic amendments. Cup-level analysis also showed data gaps. Green coffee production often contributes over half of GHG impacts, but many studies used secondary datasets that poorly reflect actual sourcing. Water and energy assumptions varied, especially regarding wasted coffee. Conclusions & Perspectives: Variability and uncertainty stem from both system differences and inconsistent data or methods. Although LCA standards exist, methodological choices and data quality vary. More primary data are needed—especially on agroforestry interactions and emissions from organic fertilisers. Finally, incorporating sensory qualities into LCA's functional unit may improve the relevance of impact comparisons among coffee types.