LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PARALLEL SESSION 2A: LAND USE 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
Development of an integrated indicator for land use based on the
economic value of ecosystem services
Viêt Cao 1,2,* , Manuele Margni 2 , Basil D. Favis 3 , Louise Deschênes 1
1
CIRAIG, Department of Chemical Engineering, Polytechnique Montréal, P.O. Box 6079, Station Centre-ville, Montréal, Québec
H3C 3A7, Canada 1
2
CIRAIG, Department of Mathematical and Industrial Engineering, Polytechnique Montréal, P.O. Box 6079, Station Centre-ville,
Montréal, Québec H3C 3A7, Canada
3
CRÉPEC, Department of Chemical Engineering, Polytechnique Montréal, P.O. Box 6079, Station Centre-ville, Montréal, Québec
H3C 3A7, Canada
*
Corresponding author. E-mail: viet.cao@polymtl.ca
ABSTRACT
Soils are one of Earth's essential natural resources, supporting nearly all terrestrial life. In life cycle impact assessment (LCIA), potential
impacts due to land use are calculated as the product of surface occupied (or transformed), occupation (or transformation) time
and a parameter describing the land quality loss (ΔQ) (Mila iCanals et al., 2007). In current LCIA methodologies, the only operational
endpoint level indicator for the land quality loss is solely related to terrestrial biodiversity (PDF.m 2 .year, PDF being Potential
Disappeared Fraction of species) and is not representative of all impacts that originate from land use as shown by a recent project
named LULCIA (2008-2012), conducted under the aegis of the UNEP/SETAC Life Cycle Initiative (Koellner et al., 2012; de Baan et
al., 2012; Saad et al., 2011; Brandão and Mila iCanals, 2012; Müller-Wenk and Brandão, 2010).
This project expanded the scope of land use assessment, going beyond the biodiversity assessment. This method relates land use to
six additional indicators: biotic production potential (BPP), erosion regulation potential (ERP), fresh water regulation potential
(FWRP), (mechanical and physico-chemical) water purification potential (WPP) and carbon sequestration potential (CSP), which
represent provision and regulation services from ecosystems, as defined in the Millennium Ecosystem Assessment (MEA) (2005).
Although the LCIA methodology becomes more comprehensive for relevant pathways linked to land use, this development potentially
reduces the capacity of LCA as a decision support system, providing seven midpoints for the land use impact category alone.
This project aims to develop a new method to value the reduction of ecosystem services provided to human society. The method
consists in converting the above mentioned midpoint indicators in monetary terms, using economic valuation of the reduction of a
given ecosystem service. BPP is estimated with productivity loss while CSP thanks to carbon social cost: less sequestration by soils
is equivalent to emission. The other regulation services are estimated through current compensation costs, as they are considered
essential (conservative approach).
This method is applied on a case study, the comparative LCA of bio-based polymers. Results show that impact scores are not only
influenced by the bio-geographical variability of systems under study (e.g. crop yield in the inventory flow, the land location for the
impact characterisation), but also by the socio-economical availability and typology of the compensation systems taken into account.
Uncertainties and economic valuation assumptions are further discussed in the paper.
Overall this work shows the feasibility to translate all the midpoints indicators proposed by the LULCIA land use impact assessment
framework into economic values, bringing a new level of interpretation for the decision maker. The converted indicators can be
summed into an integrated indicator expressing potential impacts and they must be interpreted as the loss of natural (capital of) ecosystem
services. It also potentially allows LCA to assess other impacts related to land use, such as aesthetics and recreational aspects
(as they are conceptualised as cultural services in the MEA framework).
Keywords: land use, integrated indicator, ecosystem services, economic valuation, impact assessment
1. Introduction
In life cycle impact assessment (LCIA), midpoint potential impacts due to land use are calculated as the
product of surface occupied (or transformed), occupation (or transformation) time and a parameter describing
the land quality loss (ΔQ) (Mila i Canals et al., 2007). So far, this latter is solely related to terrestrial
biodiversity (PDF.m 2 .year, PDF being Potential Disappeared Fraction of species), which is certainly not
representative of all impacts caused by human interventions, that originate from land use as shown by a recent
project named LULCIA (2008-2012), conducted under the aegis of the UNEP/SETAC Life Cycle Initiative
(Koellner et al., 2012; de Baan et al., 2012; Saad et al., 2011; Brandão and Mila iCanals, 2012; Müller-
Wenk and Brandão, 2010) and also partly assessed by the European Commission JRC ILCD handbook
(2010).
Soil quality is both an important and difficult ecosystem component to assess, because of the variety of
both soil quality definitions and approaches possible (Garrigues et al., 2011). The “quest” for a synthetic
indicator is even more difficult with both the different intended meaning and public possible.
This method relates land use to six new indicators in addition to biodiversity: biotic production (BPP),
erosion regulation (ERP), fresh water regulation (FWRP), mechanical and physicochemical water purification
(MWPP and PCWPP) and carbon sequestration (CSP) potentials, which represent provision and regulation
ecosystem services, as defined in the Millennium Ecosystem Assessment (2005). Ecosystem service is a
relative new concept, which makes the link between ecological functions and the service they provide to by
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