Bárbara María Civit

UNEP-SETAC guideline on global land use impact assessment on biodiversity and ecosystem services in LCA

PurposeAs a consequence of the multi-functionality of land, the impact assessment of land use in Life Cycle Impact Assessment requires the modelling of several impact pathways covering biodiversity and ecosystem services. To provide consistency amongst these separate impact pathways, general principles for their modelling are provided in this paper. These are refinements to the principles that have already been proposed in publications by the UNEP-SETAC Life Cycle Initiative. In particular, this paper addresses the calculation of land use interventions and land use impacts, the issue of impact reversibility, the spatial and temporal distribution of such impacts and the assessment of absolute or relative ecosystem quality changes. Based on this, we propose a guideline to build methods for land use impact assessment in Life Cycle Assessment (LCA).ResultsRecommendations are given for the development of new characterization models and for which a series of key elements should explicitly be stated, such as the modelled land use impact pathways, the land use/cover typology covered, the level of biogeographical differentiation used for the characterization factors, the reference land use situation used and if relative or absolute quality changes are used to calculate land use impacts. Moreover, for an application of the characterisation factors (CFs) in an LCA study, data collection should be transparent with respect to the data input required from the land use inventory and the regeneration times. Indications on how generic CFs can be used for the background system as well as how spatial-based CFs can be calculated for the foreground system in a specific LCA study and how land use change is to be allocated should be detailed. Finally, it becomes necessary to justify the modelling period for which land use impacts of land transformation and occupation are calculated and how uncertainty is accounted for.DiscussionThe presented guideline is based on a number of assumptions: Discrete land use types are sufficient for an assessment of land use impacts; ecosystem quality remains constant over time of occupation; time and area of occupation are substitutable; transformation time is negligible; regeneration is linear and independent from land use history and landscape configuration; biodiversity and multiple ecosystem services are independent; the ecological impact is linearly increasing with the intervention; and there is no interaction between land use and other drivers such as climate change. These assumptions might influence the results of land use Life Cycle Impact Assessment and need to be critically reflected.Conclusions and recommendationsIn this and the other papers of the special issue, we presented the principles and recommendations for the calculation of land use impacts on biodiversity and ecosystem services on a global scale. In the framework of LCA, they are mainly used for the assessment of land use impacts in the background system. The main areas for further development are the link to regional ecological models running in the foreground system, relative weighting of the ecosystem services midpoints and indirect land use.

Principles for life cycle inventories of land use on a global scale

PurposeTo assess the diverse environmental impacts of land use, a standardization of quantifying land use elementary flows is needed in life cycle assessment (LCA). The purpose of this paper is to propose how to standardize the land use classification and how to regionalize land use elementary flows.Materials and methodsIn life cycle inventories, land occupation and transformation are elementary flows providing relevant information on the type and location of land use for land use impact assessment. To find a suitable land use classification system for LCA, existing global land cover classification systems and global approaches to define biogeographical regions are reviewed.Results and discussionA new multi-level classification of land use is presented. It consists of four levels of detail ranging from very general global land cover classes to more refined categories and very specific categories indicating land use intensities. Regionalization is built on five levels, first distinguishing between terrestrial, freshwater, and marine biomes and further specifying climatic regions, specific biomes, ecoregions and finally indicating the exact geo-referenced information of land use. Current land use inventories and impact assessment methods do not always match and hinder a comprehensive assessment of land use impact. A standardized definition of land use types and geographic location helps to overcome this gap and provides the opportunity to test the optimal resolution of land cover types and regionalization for each impact pathway.Conclusions and recommendationThe presented approach provides the necessary flexibility to providers of inventories and developers of impact assessment methods. To simplify inventories and impact assessment methods of land use, we need to find archetypical situations across impact pathways, land use types and regions, and aggregate inventory entries and methods accordingly.

Determination of regional acidification factors for Argentina

PurposeIn the last decade, the use of life cycle assessment (LCA) as a tool for selection between different technologies or products fulfilling the same function has spread rapidly in Latin American countries. However, this accelerated growth in the use of LCA has not always been supported with progress in construction of local inventories or the development of impact assessment methods that consider local and regional characteristics of the sites where technologies, products, and activities or services are being produced or developed. The aim of this study is to propose a local methodology to estimate regional factors for the terrestrial acidification impact category in Argentina based on the critical load exceedance in sensitive areas.Material and methodsAcidification factors for ecological regions in Argentina were calculated following a procedure that compares acidic deposition with critical loads, using a linear function to represent the damage, when the deposition is above the soil buffering capacity. The acidic deposition in the study area was estimated using the air transport model wind trajectory model, with emissions from the global inventory EDGAR. Detailed soil maps were used in order to include the acidification sensitivity of the receiving ecosystems. Also, an application case of the calculated factors is presented in order discuss the relevance of the regional factors implementation in local studies.Results and discussionDeposition fluxes were estimated for different ecoregions in Argentina. The regional factors calculated differ from site-generic factors used commonly to estimate potential impacts, demonstrating that their use in local studies could lead to erroneous outcomes. This was more evident in the application case, where the potential impact calculated was very different, depending on the impact factor used.Conclusions and recommendationsThe model presented in this study allows the assessment of the impact caused by deposition of acidifying substances emitted during the life cycle of a product or process, taking into account the local characteristics where the intervention occurs, and it is the first development of a regional model for acidification within the LCA context carried out in Argentina. The obtained results highlight the importance of developing regional characterization factors for local or regional impacts referred to a definite region.