Towards Global Guidance for LCIA Indicators and Methods – Pellston Workshop

After a period in which many people worked hard to make LCA easier to do and interpret, the latest developments are mostly focused at making LCA more efficient by standardization. An important initiative is the Flagship 1b project of UNEP SETAC Life Cycle Initiative, which aims at a global consensus and guidance for a limited number of life cycle impact category indicators. This article is a short overview of the progress so far.

At the beginning of this year, a one week preeminent so-called Pellston Workshop™ on “Global guidance for Life Cycle Impact Assessment Indicators and Methods” was organized in Valencia, Spain. The goal of the workshop was to reach consensus on recommended environmental indicators and characterization factors (e.g. metrics, modeling approach, units, scale and reporting framework) for global warming, particulate matter emissions, water use impacts (both scarcity and human health impacts), land use impacts on biodiversity plus cross-cutting issues and LCA-based footprints. Forty participants – who formed a well-balanced multi-regional mixture of LCA experts and experts in specific topics or areas of protection, users from industry, governments and NGOs – joined the intensive discussions. The workshop was a fruitful one, and the outcomes were brought to a broader audience at the SETAC conference in Nantes in May this year.


Outcomes from the Pellston Workshop™

Apart from tables with recommended characterization factors to operationalize the application of the recommended indicators, the following recommendations were agreed upon:



The overall framework for LCIA was slightly revised, structuring the damage categories according to three value types:

Intrinsic values Instrumental values Cultural values
Human Health

(morbidity and mortality)

Socio-economic assets

(man-made environment, e.g. built infrastructure, cash crops, etc.)

Cultural heritage

(buildings, historic monuments, artwork, etc)

Ecosystem Quality


(e.g. biodiversity loss in terms of species richness and vulnerability)

Natural resources and Ecosystem services

(e.g. mineral primary resources, ecosystem services

Natural heritage


(e.g. flora, fauna, geological elements)


Crosscutting issues

The recommended indicator for human health is the number of disability adjusted life years (DALYs) based on calculations without age weighting and without discounting (for explanation, click here). For ecosystem quality it is the potentially disappeared fraction of species (PDF) or a unit that can translated to PDF. For natural resources and ecosystem services, no decision has been made yet.


With regards to spatial differentiation, it was agreed that the choice of scale should always be reported and that the format should be standardized. Similarly, uncertainties should be made explicit and at least qualitatively included. In any case, transparent reporting is a must.


Climate change

Climate change involves a number of environmental mechanisms that affect both human health and the natural environment. Man-made climate change is caused by the emission of greenhouse gases, which absorb infrared radiation from the earth, and by other activities influencing their atmospheric concentration. In general, climate change models are developed to assess the future impact on climate resulting from different policy scenarios. The outcomes from the Pellston Workshop™ include the recommendation to use two metrics from the 5th IPCC assessment report (2013), namely Global Warming Potential 100 year (GWP-100), representing the shorter term impacts of climate change, and Global Temperature Potential 100 years (GTP-100), representing the long term climate change impacts. Furthermore, it is also recommended to use the metrics including climate-carbon cycle feedbacks for all climate forcers (so far only included for CO2) and to address the climate change impacts of near term climate forcers in sensitivity analyses.


Land use

The impact category land use reflects the damage to ecosystems due to the effects of occupation and transformation of land. Examples of land use are agricultural production, mineral extraction and human settlement. The characterization factors represent global potential species loss from land use. They are only provisionally recommended for hotspot analysis in LCA, but not for comparative assertions or eco-labelling. In order to provide full recommendation, further testing of the CFs and additional development of CFs for other land use types are required.


Water use

This impact category considers the stress on the environment and humans related to water scarcity. For now, AWaRe is the recommended midpoint indicator for water scarcity. It is based on the relative Available Water Remaining in a water shed, after the demand of humans and aquatic ecosystems has been met. For the water use impacts on human health, characterization factors that represent agricultural water deprivation impacts are recommended, as well as additional tests in LCA case studies. The first six case studies are already available on AWaRe’s website.


Particulate matter

One of the most important contributors to the global human burden of disease is fine particulate matter with a diameter smaller than 2.5 micrometer (PM2.5). Fine dust can be classified as primary or secondary, depending on its formation. Primary PM is emitted in particle form at the source, e.g. the smokestack of an electrical power plant. Secondary PM sources directly emit air contaminants into the atmosphere that form or help form PM. Examples of such PM precursors include SOx, NOx, VOCs, and ammonia. PM2.5 are the most harmful of all fine dust, because their size enables them to penetrate deeply into the lungs. The use of different models currently leads to inconsistent LCIA results. Therefore, there has been a great need for a harmonized approach for this impact category. In the recommendations, primary PM characterization factors and interim secondary PM characterization factors are established. Human health effects from PM2.5 outdoor and indoor releases are both being incorporated, and various source and exposure archetypes are being distinguished, e.g. ground level versus stack PM emissions, and rural versus urban areas.

SETAC Pellston Workshop Outcomes - Life Cycle Impact Assessment Indicators and Methods
The Pellston Workshop™ should provide a global guidance publication for a limited number of impact category indicators with recommended characterization factors | Image credit: EeBGuide



The results from the workshop including all recommendations are now being finalized in a series of scientific publications. The official launch of the Valencia Guidance on LCIA is scheduled for the Eco-balance conference 2016. In a second stage, the project will address human toxicity, ecotoxicy, acidification, eutrophication, and energy resources. Furthermore, the project aims to provide recommendations on how to integrate these individual indicators in a consistent framework, ensuring consistency of indicator selection process and assessment across impact categories. The ultimate deliverable of the Flagship 1b project would be a global guidance publication with a supporting web system that includes the limited number of 6 to 10 LCA-based environmental impact category indicators and the characterization factors for various regions. At PRé, we will do our best to make the recommended Life Cycle Impact Assessment indicators and methods available in SimaPro as soon as possible.


The results of the Pellston Workshop™ exceeded the rather high expectations of the participants. I agree with them that great progress has been made. Not only are we well on track in making LCA more efficient by standardization, the Flagship 1b project also brought us one step closer to a harmonized approach with consistent Life Cycle Impact Assessment indicators and methods, thus consistent results.


For more information on the activities of the Flagship 1b project, you can contact its co-chairs, Rolf Frischknecht and Olivier Jolliet. If you want to have a better understanding of Life Cycle Impact Assessment indicators and methods, of the implications of this and other projects towards LCA standardization, contact me or one of my colleagues. We can help answer your questions.

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