Arnold Tukker

Surrey (UK), 3 September 2015 – The development of an integrated resource index of nations has been the theme of a scientific expert session organized back-to-back with the International Society for Industrial Ecology Conference 2015, in Surrey, Monday 6 July. The session has been organized by CML, Leiden University and the WRF Secretariat. After a welcome and introduction by Bas de Leeuw, WRF Managing Director, Arnold Tukker briefly presented the discussion document ‘Towards a resource index of nations’ (Arnold Tukker, CML, Leiden University and TNO, Netherlands). A panel composed by Stephanie Hellweg (ETH), Mark Huijbregts (Nijmegen), Francesca Verones (NTNU) reacted on the document and on the open questions. This was then followed by a general discussion with the audience.

Main outcomes of the workshop are:

1. At least materials, water and land should be included in the index. Inclusion of carbon is controversial, since not a resource in strict terms but related to impacts. It has been suggested to consider energy instead of GHG emissions. The Swiss Federal Office of the Environment (FOEN) in a note sent to WRF suggested also including air and biodiversity.
2. Both a consumption- as production perspective is relevant.
3. Data-mining is becoming quite robust and a consensus is being reached on the methodology. For water, a reasonable consensus exists how to create an index that takes into account water scarcity at the point of extraction (most notably in the form of the water stress index proposed by Pfister et al.). For land use and materials only moderate to low consensus exists of how to aggregate within these resource categories. No consensus has been found in relation to this point. The question on how to aggregate land use and materials remains open.
4. There is also low consensus about weighting/aggregating across resource categories. Options to consider include panel methods or methods converting individual resource use values for water, land and materials to indices between 0 and 1 followed by multiplication and taking the cube root of the 3 indices to come to a single indicator, as done e.g. in calculating the Human Development Indices from 3 other partial indices. This is a very basic way of aggregating indicators. Would a more complex method bring better results? Would outcomes still be understandable by the broad public? A balance should be found between simplicity and soundness of results (i.e. which will help tracking measures taken at the country level and which should not bring to rebound effects). What about not aggregating the various indicators (i.e. having an indicator for water, land, material and energy but not a single number)?
5. It is utterly important to identify which is the aim of decision-makers (e.g. reducing environmental impacts all along the whole life cycle of materials) and what do they need to know in order to act. Only then can be identified the underlying scientific research questions that can be addressed to help decision-makers in their work.

Surrey workshop participants

The following next steps were suggested:

• Keep it simple: use on of the existing MR EE IO databases (WIOD, EORA, EXIOBASE) to calculate footprints, or maybe all of them
• Use the following ways of aggregation within resource categories:

– Water: Pfister et al., 2009

– Land: t.b.a. (use pragmatically an LCIA method well accepted)

– Materials: t.b.a.(use pragmatically an LCIA method well accepted)

• Use explicit weighting:

– Existing panel values

– New panel values

• or copy the HDI weighting method (which would require normalisation on minimal and maximum footprints per capita, which is a discussion in itself)

The discussion will be continued at WRF 2015. For more information, see the presentation given by Arnold Tukker. Feel free to write your comments on this article to Cecilia Matasci (cecilia.matasci@wrforum.org).