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ABSTRACT: It is expected that biodiesel production in the EU will remain the dominant contributor as part of a 10% minimum binding target for biofuel in transportation fuel by 2020 within the 20% renewable energy target in the overall EU energy mix. Life cycle assessments (LCA) of biodiesel to evaluate its environmental impacts have, however, remained questionable, mainly because of the adoption of a traditional process analysis approach resulting in system boundary truncation and because of issues regarding the impacts of land use change and N(2)O emissions from fertilizer application. In this study, a hybrid LCA methodology is used to evaluate the life cycle CO(2) equivalent emissions of rape methyl ester (RME) biodiesel. The methodology uses input-output analysis to estimate upstream indirect emissions in order to complement traditional process LCA in a hybrid framework. It was estimated that traditional LCA accounted for 2.7 kg CO(2)-eq per kg of RME or 36.6% of total life cycle emissions of the RME supply chin. Further to the inclusion of upstream indirect impacts in the LCA system (which accounted for 23% of the total life cycle emissions), emissions due to direct land use change (6%) and indirect land use change (16.5%) and N(2)O emissions from fertilizer applications (17.9%) were also calculated. Structural path analysis is used to decompose upstream indirect emissions paths of the biodiesel supply chain in order to identify, quantify, and rank high carbon emissions paths or 'hot-spots' in the biodiesel supply chain. It was shown, for instance, that inputs from the 'Other Chemical Products' sector (identified as phosphoric acid, H(3)PO(4)) into the biodiesel production process represented the highest carbon emission path (or hot-spot) with 5.35% of total upstream indirect emissions of the RME biodiesel supply chain.
Environmental Science & Technology 02/2011; 45(6):2471-8. · 4.80 Impact Factor
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ABSTRACT: In recent years there have been a number of attempts to develop a more comprehensive approach to the issue of measuring resource use and/or pollution generation embodied in trade flows, including contributions that combine input–output techniques and Ecological Footprint analysis. In this two-part paper we describe how to enumerate the resource and/or pollution content of inter-regional and inter-national trade flows (Part 1) and we present a literature review of recent methodological and empirical developments (Part 2). It is straightforward in principle to extend the basic input–output approach to capture international trade flows. However, in practice, problems of data availability and compatibility, and of computability of extended input–output matrices, mean that simplifying assumptions are generally applied, but with the implications of these assumptions often not made fully explicit. What appears to be absent from previous applications is an account of the analytical method by which Ecological Footprints should ideally be estimated in an international input–output accounting analysis. This allows an explicit analysis of the problems that prevent the application of the full method and identification of the most appropriate short-cut methods in a transparent way. The objective of this paper is to provide such an account.
Ecological Economics 02/2007; · 2.71 Impact Factor
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ABSTRACT: This paper offers a detailed review of recently described single- and multi-region input–output models used to assess environmental impacts of internationally traded goods and services. It is the second part of a two-part contribution. In Part 1 [Turner, K., Lenzen, M., Wiedmann, T. and Barrett, J. in press. Examining the Global Environmental Impact of Regional Consumption Activities — Part 1: A Technical Note on Combining Input–Output and Ecological Footprint Analysis; Ecological Economics.] we describe how to enumerate the resource and pollution content of inter-regional and inter-national trade flows with the aim to illustrate an ideal accounting and modelling framework for the estimation of Ecological Footprints.A large number of such environment-economic models have been described but only in the last few years models have emerged that use a more sophisticated multi-region, multi-sector input–output framework. This has been made possible through improvements in data availability and quality as well as computability. We identify six major models that employ multi-sector, multi-region input–output analysis in order to calculate environmental impacts embodied in international trade. Results from the reviewed studies demonstrate that it is important to explicitly consider the production recipe, land and energy use as well as emissions in a multi-region, multi-sector and multi-directional trade model with global coverage and detailed sector disaggregation. Only then reliable figures for indicators of impacts embodied in trade, such as the Ecological Footprint, can be derived.
Ecological Economics 01/2007; 61(1):15-26. · 2.71 Impact Factor
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Ecological Economics 01/2007; 61(1):15-26. · 2.71 Impact Factor
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ABSTRACT: We present and discuss a method that allows the disaggregation of national Ecological Footprints by economic sector, detailed final demand category, sub-national area or socio-economic group. This is done by combining existing National Footprint Accounts with input–output analysis. Calculations in the empirical part are carried out by using supply and use tables for the United Kingdom, covering the reporting period 2000. Ecological Footprints are allocated to detailed household consumption activities following the COICOP classification system and to a detailed breakdown of capital investment. The method presented enables the calculation of comparable Ecological Footprints on all sub-national levels and for different socio-economic groups. The novelty of the approach lies in the use of input–output analysis to re-allocate existing Footprint accounts, in the detail of disaggregation by consumption category and in the expanded use of household expenditure data. This extends the potential for applications of the Ecological Footprint concept and helps to inform scenarios, policies and strategies on sustainable consumption. The method described in this paper can be applied to every country for which a National Footprint Account exists and where appropriate economic and environmental accounts are available. The approach helps to save time in data collection and improves the consistency between Ecological Footprint estimates for a particular human society from different researchers. For these reasons, the suggested methodology includes crucial steps on the way towards a standardisation of Ecological Footprint accounts.
Ecological Economics 02/2006; 56(1):28-48. · 2.71 Impact Factor
