Assessing potential desertification environmental impact in life cycle assessment

Abstract

Background, aim and scope Life cycle assessment (LCA) enables the objective assessment of global environmental burdens associated with the life cycle of a product or a production system. One of the main weaknesses of LCA is that, as yet, there is no scientific agreement on the assessment methods for land-use related impacts, which results in either the exclusion or the lack of assessment of local environmental impacts related to land use. The inclusion of the desertification impact in LCA studies of any human activity can be important in high-desertification risk regions.Main features This paper focuses on the development of a methodology for including the desertification environmental impact derived from land use in LCA studies. A set of variables to be measured in the life cycle inventory (LCI), their characterisation factors (CFs) and an impact assessment method for the life cycle impact assessment (LCIA) phase are suggested. The CFs were acquired using a geographical information system (GIS). Results For the LCI stage it is necessary to register information on: (1) the four biophysical variables of aridity, erosion, aquifer overexploitation and fire risk, with a created scale of values; (2) the geographical location of the activity and (3) the spatial and temporal extension of the activity. For the CFs, the four LCI biophysical variables in (1) were measured for the main terrestrial natural regions (ecoregions) by means of GIS. Discussion Using GIS, calculation of the CF for the aridity variable shows that 38% of the world area, in eight out of 15 existing ecoregions, is at risk of desertification. The most affected is the tropical/subtropical desert. The LCIA model has been developed to identify scenarios without desertification impact. Conclusions The developed method makes possible the inclusion of the desertification impact derived from land use in LCA studies, using data generally available to LCA users. Recommendations and perspectives While this LCIA model may be a simplified approach, it can be calibrated and Responsible editor: Llorenç Milà i CanalsPreamble In this series of two papers, methodological aspects related to the assessment of desertification environmental impact in life cycle assessment (LCA) are discussed (Part 1), and the operational method and characterisation factors suggested are put into practise in a case study of energy crops in different regions worldwide (Part 2).

Preface

“…Finally, from a methodological perspective, the region lacks experience when it comes to developing specific characterization factors at a local and regional level, although certain experiences have already been developed for desertification (Núñez et al 2010). Nevertheless, global assessment methods, such as the Impact World + method (Boulay et al 2011;Helmes et al 2012), have recently included regional characterization factors for different regions at a global level.…”

Why Include Impacts on Biodiversity from Land Use in LCIA and How to Select Useful Indicators?

“…Mila i Canals et al [87] focus on water availability as a typical example (included in Table 1). Other examples are Maes et al [55] focusing on water supply, Nuñez et al [121] addressing desertification and Mila i Canals et al [122] focusing on soil organic matter. Even though several of these aspects are relevant for biodiversity [123], no link between these aspects and the actual rate of pressure on biodiversity is proposed in the papers, and consequently, these proposals cannot be used as they are to quantify changes in biodiversity.…”

Coupling GIS and LCA for biodiversity assessments of land use

“…To assess desertification potential, Núñez et al (2010) used GIS to calculate a score as an elementary flow along with ecoregion-specific characterization factors. Combining these values with the area of the process and the area of the ecoregion determined the impact.…”