EIPOT Final Project Report - Stockholm Environment Institute

ERA-NET SKEP Project EIPOT (www.eipot.eu)
“Development of a methodology for the assessment of global environmental impacts of traded goods and services”
Hybrid LCA can be used to estimate the embodied impacts of traded goods and services. While
national SRIO hybrid LCA studies have been described in the literature, no trade specific analysis has
yet been published. However, it is conceivable that process-based analyses of international supply
chains could be combined with data from MRIO models. Such a method would especially be suited to
complex commodities.
From a statistical point of view, process LCA data play three roles: firstly, to provide "disaggregation
factors" that allow representation of NAMEA data at a lower aggregation level than allowed by the
confidentiality restrictions on the original NAMEA data, and at lower levels than possible from the way
NAMEA data are collected. Secondly, process-specific emission factors can help to replace or qualify
average emission intensities of IO sectors. And thirdly, Life Cycle Impact Assessment (LCIA) provides
characterisation factors needed to express environmental pressures as impacts (see Section 4.5.1).
Below we provide several examples of recent hybrid LCA studies 17 to demonstrate the feasibility
and usefulness of such approaches, even if they do not explicitly deal with traded goods and services.
Benders et al. (2001) developed a tiered hybrid analysis tool for determining energy use and
greenhouse gas emissions related to household consumption items focussing on reduction in energy
use and greenhouse gas emissions. This tool, the energy analysis program (EAP), is a computer
program that consists of a number of fill-in screens corresponding to steps in a hybrid method
(developed by van Engelenburg et al. 1994) in which some main steps are covered with LCA data and
some minor steps with input-output data. One of the applications of the program concerns the
calculation of the total energy requirement of Dutch households by combining household budget data
with energy intensities of about 350 products and services (Biesiot and Moll 1995).
The environmental assessment study of Swedish agriculture presented by Engström et al. (2007) is a
classical example of tiered hybrid analysis where SRIO model data are extended or replaced with
process LCA data. This is done for the purpose of specifying emission intensities (such as for N 2 O
emissions from the production of nitrogen fertilizers which fall under the broad IO sector of 'chemical
products) or for extending pressure variables to LCA impact categories such as global warming,
acidification, eutrophication and so on.
Similar tiered hybrid analyses have been run by Kofoworola and Gheewala (2008) for the life cycle
assessment of an office building in Thailand or by Junnila (2008) for the life cycle management of
energy-consuming products. In these cases LCA data describe site-specific processes that replace IO
data or augment these by adding downstream life cycle impacts to the system.
The quantification of impacts from international transportation is an important area for tiered hybrid
analysis using process data. The main question is how to assign emissions from the combustion of
fuels from bunkers for international aviation and shipping. From a production perspective (such as
when following SNA93 principles; United Nations Statistics Division 1993), bunker emissions should
be assigned to ship or plane operators’ country of domicile and – in the case of passenger transport –
counted as exports if passengers are non-resident, otherwise as domestic consumption. From a
consumption perspective (as taken by an EIPOT MRIO model), emissions of residents using
international passenger transport should be counted as consumption emissions of their country. For
goods, bunker emissions from imports are allocated to country of import and bunker emissions from
exports are not counted. In any case a bottom-up approach using process data is needed, which
requires the following information:
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The selection is non-exhaustive.
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