GLAM: global guidance for LCIA indicators and methods
Life cycle impact assessment (LCIA) translates life cycle inventory results into indicators of potential environmental impacts. However, the diversity of methods, characterisation factors and assumptions can make studies difficult to compare and results harder to interpret.
The GLAM initiative (Global Guidance for Life Cycle Impact Assessment Indicators and Methods) was launched by the Life Cycle Initiative to promote stronger scientific consensus and global guidance on LCIA indicators and methods.
From category-specific harmonisation to a comprehensive method
The early phases addressed specific impact categories, including climate change, particulate matter, water use, land use, acidification, eutrophication, toxicity and resources. The third phase aimed to move towards a more comprehensive framework covering classification, midpoint and endpoint indicators, normalisation and weighting.
The development process involved experts from different regions and consultations with the scientific community and other stakeholders. The aim is not to stop research or methodological development, but to provide a coherent global foundation supported by scientific evidence and transparent documentation.
What has changed since the 2021 publication?
The work has progressed well beyond the phase described in the original article. Following development and expert consultations, beta factors were presented for discussion in 2024 and GLAM 1.0 was launched in October 2024. Further feedback was gathered in 2025 to prepare a comprehensive update. The stewardship phase, beginning in 2026, is intended to maintain the method as a living scientific reference.
Why does this matter to LCA practitioners?
Global guidance can support method selection, documentation of choices and interpretation of results. Nevertheless, the suitability of an indicator depends on the study goal and scope, data quality, and the environmental and geographical relevance of the category being assessed.
GLAM is an important step towards more consistent LCIA, but it does not remove the need for methodological transparency or critical review by practitioners.