From: tomase@entek
Sent: Wednesday, May 22, 2002 12:15 PM
To: <
Subject: Re: Method Development - Limitations of Consequentia
LCA
Dear Tim and Rita,
Thanks for
your input. Patrick, Bo, and I have had this discussion since
long before the conference and it is good that other people make
their opinion heard.
Tim is correct, of course, in that our
discussion is complex and theoretical. The ideal, consequential
methodology that we discuss may not be practical or possible to
"sell". However, I think that it is important to have
a good theoretical understanding of the ideal methodology as a
basis for discussions on what simplifications are justified to
obtain a practical methodology. And a good theoretical foundation
can be a strong argument when "selling" the methodology.
I agree with
your main point that stakeholders should be involved in the choice
of methodology. As Rita indicates, it is particularly valuable
to involve the decision-makers that the LCA is intended to inform.
Different methods result in different types of information, and
different information can be relevant for different decision-makers.
However, Tim's message can be interpreted to say that stakeholders
should not be allowed to freely choose the methodology that rewards
their own products or confirm their own prejudices. If this happens,
LCA will quickly loose whatever credibility it has. Instead, I
believe that we need a structured procedure to identify, in each
case, what information is relevant to the decision-makers.
Tim mentions
the specific problem of the recycled content in consequential
LCAs. This can be solved - at least in principle - through
the use of price elasticities (see Ekvall T A
market-based approach to allocation at open-loop recycling,
RESOUR CONSERV RECY 29 (1-2): 91-109 APR 2000). The approach
presented in that paper is based on the notion that materials
are limited by supply or demand only. If the market is sufficiently
free, supply and demand are in a state of equilibrium
that is maintained through changes in price. The paper presents
not only the "ideal" methodology but also a few simplifications.
Best regards,
Tomas
-----
Original Message -----
From:
Tim Grant
Sent:
Wednesday, May 22, 2002 4:25 PM
Subject:
Re: Method Development - Limitations of Consequentia LCA
Dear Tomas, Bo
and Patrick and otehrs followng this thread
Having watch this debate over the last two days, my main
observation is the complexity of the debate and how is a
real applied LCA, you manage to "sell" the appropriate
methdology - We have trouble selling LCA at all
above just greenhouse assessments.
However in
a recent study in Australia we have stakeholders in an LCA
asking for consequential LCA as they were unhappy with
the emissions being allocated to their fuel (ethanol) from the
sugar industry in a attributional LCA approach.
But in the building industry, there is strong support for
recycled content in everything from steel through to plastics
and concrete. The consequential LCA approach would suggest
this suppport was misplaced, but this is not a welcome message.
- also some materias are on the border between supply limited
and demand limited in recycled material - and may shift back and
forth.
My main point here really
is that the decision on the methodology should involve the
stakeholders and would be undertaken with condideration of the
sector, the aims of the LCA, and maybe dare I say it consideration
to the simplicity in the modellling and subsequent communication
and verification of the results - these assumptions will
generally need to become more explicit.
regards
Tim Grant
============================================
Tim Grant, BAppSci, MEng
Program Manager- Life Cycle Assessment
Centre for Design at RMIT
GPO Box 2476V, Melbourne, Victoria 3001, Australia
Ph: 61 (0)3 9925 3490
Fax: 61 (0)3 9639 3412
Mobile: 0408 104 977
URL:
http://www.cfd.rmit.edu.au
============================================