Methodology

Quick introduction into ReCiPe LCIA Methodology

Life cycle assessment (LCA) is a methodological tool used to quantitatively analyse the life cycle of products/activities. ISO 14040 and 14044 provide a generic framework.

After goal and scope has been determined, data has been collected, an inventory result is calculated. This inventory result is usually a very long list of emissions, consumed resources and sometimes other items. The interpretation of this list is difficult. An LCIA procedure, such as the ReCiPe method is designed to help with this interpretation.

 Indicators

The primary objective of the ReCiPe method, is to transform the long list of Life Cycle Inventory results, into a limited number of indicator scores. These indicator scores express the relative severity on an environmental impact category. In ReCiPe we determine indicators at two levels:
  • 1. Eighteen midpoint indicators
  • 2. Three endpoint indicators

ReCiPe uses an environmental mechanism as the basis for the modelling. An environmental mechanism can be seen as a series of effects that together can create a certain level of damage to for instance, human health or ecosystems. For instance, for climate change we know that a number of substances, increases the radiative forcing, this means heat is prevented from being radiated from the earth to space. As a result, more energy is trapped on earth, and temperature increases. As a result of this we can expect changes in habitats for living organisms, and as a result of this species may go extinct.

From this example it is clear that the longer one makes this environmental mechanism the higher the uncertainties get. The radiative forcing is a physical parameter, that can be relatively easily measured in a laboratory. The resulting temperature increase is less easy to determine, as there are many parallel positive and negative feedbacks. Our understanding of the expected change in habitat is also not complete, etc.


Figure 1: Example of a harmonised midpoint-endpoint model for climate change, linking to human health and ecosystem damage.

So the obvious benefit of taking only the first step is the relatively low uncertainty.


Combining mid- and endpoints

In ReCiPe we indeed calculate eighteen of such midpoint indicators, but also calculate three much more uncertain endpoint indicators. The motivation to calculate the endpoint indicators, is that the large number of midpoint indicators are very difficult to interpret, partially as there are too many, partially because they have a very abstract meaning. How to compare radiative forcing with base saturation numbers that express acidification? The indicators at the endpoint level are intended to facilitate easier interpretation, as there are only three, and they have a more understandable meaning

 The idea is that each user can choose at which level it wants to have the result:
  • Eighteen robust midpoints, that are relatively robust, but not easy to interpret
  • Three easy to understand, but more uncertain endpoints:
  • Damage to Human health
  • Damage to ecosystems
  • Damage to resource availability

 The user can thus choose between uncertainty in the indicators, and uncertainty on the correct interpretation of indicators.

   

 The figure below provides the overall structure of the method:


Figure 2: Relationship between LCI parameters (left), midpoint indicator (middle) and endpoint indicator (right) in ReCiPe 2008.


Posted comments:

Phil Henshaw says:
As now designed, ReCiPe produces an inclusive "answer". What is most missing from decision maker understanding of natural and economic systems is good "questions" about their surprising independent developments and reactions to change. The modeling problem is that environments are full of independently changing actors. I'd like to discuss my methods for generating environmental system questions of that kind, and a way to tag ReCiPe lists with them. One way would be to include a list of high level alarms for approaching thresholds of instability for 'forcing factor responses', say in a footnote. Those are implied for any escalating factor not accompanied by an exit strategy, for example. Divergent progressions generally reflect the development of unstable environmental systems, and LCA can be used to flag the ones connected to its measures. edited 15:05, 7 Apr 2009
Posted 14:59, 7 Apr 2009

Johan Braet? says:
I'm used to teach ECO-INDICATOR to my applied economics last year master students, so that in their further career they could rely on a quick method for estimating environmental impacts of products and services. Of course we were well informed about the shortcomings of the mthod, but for most of us those were largely compensated by the ease of use and the avaiablity of data concerning processes and products. How (fast) will we have access to a sortlike convenience in the new method? edited 13:37, 22 Jul 2009
Posted 13:35, 22 Jul 2009

Jungbluth says:
I have evaluated different LCIA methods. For ReCiPe I found the result that electricity from nuclear energy is quite favorable compared to all other types of electricity production (be it fossil, or renewable). This seems to be even more pronounced than in the former Eco-indicator method. From a Swiss perspective this is somehow surprising. Therefore I identified two issues. - The volume of final deposits is not taken into account as a issue of a limited resource. From a political point of view this is a major issue in many countries without a final solution yet. Within the ecological scarcity method this has been considered by accounting for the volume as a limited resource. For me it would seem reasonable to account at least for the future price to be paid for such deposits. - Uranium resource is evaluated in ReCiPe by the future price. Other methods assess energy carriers by the primary energy content of the resource and thus come to more similar results at least for comparing fossil and nuclear energy. So with a methodological choice uranium has been treated separately from other nonrenewable energy carriers which might lead to biased results. Other methods like the ecological footprint or the Swiss environmental scarcity method gave a higher weight to theses issues and thus show less favorable results for nuclear power. Each of these approaches seems to be reasonable within its own logic. But, for me it seems as if each assessment on nuclear power is also a matter of choice and personal opinion and less on broadly accepted scientific foundations. So there are good scientists who have a positive picture while others have a quite negative image which is finally also shown in their judgment (in which they will weight different aspects quite differently). The opinion about this does not seem to be so much influenced by the amount of knowledge someone has about it. Has the issue of the results for nuclear power been discussed within your whole project group and is it a consensus that some issues like the final deposits are not taken into account? Is it also a general consensus within the Netherlands to consider nuclear power as the best option from an environmental point of view or are there also two groups of people one strongly in favor and one strongly against nuclear power? In my understanding you see ReCiPe as a worldwide usable method. So do you have the perception that it would be possible to get a global consensus on this issue? For me this seems to be a question that should be included somehow in the cultural perspectives used in the weighting. But after evaluating the results with the three main perspectives I also do not see a substantial different results of the assessment within the three perspectives. Have you thought about defining a perspective that would consider e.g "scarcity of final deposits for nuclear waste", "long-term risks" or "low risk of extreme accidents" as more serious? I would be interested to hear your opinion and maybe something about the discussion you had on this issue.
Posted 07:58, 8 Dec 2009

Mark says:
Dear Niels Jungbluth, Nuclear energy is indeed a debated issue, but we did not debate this in the project team. While developing ReCiPe, policy makers here in the Netherlands showed zero interest in such things. The reason why uranium is treated as a mineral and not as a fuel, is simply because it is a mineral, like a metal. Minerals were distributed in the earth crust while it was cooling down. From a geological perspective, it is distributed as a metal, and the most important parameter is the ore grade, so we can only model it as a metal. Fossil fuels were formed between 400 and 200 million years ago, and their distribution follows a completely different pattern. The "grade"of a fuel has no meaning, and this meant we had to develop a different model, in which uranium simply does not fit. Your suggestion to model the final disposal costs as part of the depletion costs in an interesting one, but It would not be realistic to do this for uranium alone, also for toxic metals, and in fact for CO2, a similar problem occurs. Many people have already commented that this is a flaw in LCA, we double count the problem of depletion with CO2, while in fact they are two sides of the same coin. It would be interesting though to try to estimate the future nuclear waste storage costs and add that to the surplus costs defined for Uranium, and see if they would change the verdict ReCiPe implies. Mark Goedkoop
Posted 14:18, 16 Dec 2009







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