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Memory lane

September 7, 2016 by Bo Weidema

I was recently asked to tell about the experiences we have at 2.-0 LCA consultants with consequential LCA. That question sent me on a long trip down memory lane…..

You will therefore find the format of this blog-post a bit unusual, with a ‘fat’ bibliography and a focus on our contributions to the field. I hope you will anyway find it worthwhile to read.

All practical applications of LCA are ultimately concerned with potential improvements of the analysed systems. Therefore, LCA is designed to model the physical consequences of a change, tracing the physical and economic causalities that result from a decision. This type of modelling is is often referred to as consequential LCA, as opposed to attributional modelling that a trace specific aspect of a value chain or supply chain back to its contributing unit processes, and that cannot say anything about the consequences of changing the analysed system.

The idea of LCA as a model of changes was initially suggested by Heintz & Baisnée (1992) and Weidema (1993), pointing out that to determine what processes to include in a product system, it is necessary to use information on how markets react to changes in demand and supply. The consequential modelling principles were later built into the ISO standards on LCA, published in 1998 (ISO 14040, 14044 and 14049; see Consequential-LCA 2015) and supported by a number of scientific publications, notably Weidema et al. (1999) and Weidema (2001a), and summarized in Weidema (2003a).

Due to the lack of flexible and geographically differentiated background databases, the initial application of the consequential modelling principles was limited to specific parts of the foreground systems. Examples of early applications can be found for metals (ISII 1997, Weidema 1999a, Weidema & Norris 2004), renewable materials (Weidema 1999b), electricity and nitrogen fertiliser (Weidema 2001b), and fish (Thrane 2004).

That a consistent consequential model could be implemented in a background database based on the introduction of flexible market activity datasets was put forward in Weidema (2003b) but not implemented in practice until ten years later, in the ecoinvent database (Weidema et al. 2013).

That marginal modelling is also applicable in IO-LCA (LCA using input-output data from the national accounts) was already pointed out in Nielsen & Weidema (2001) and consequential procedures to handle co-production have already long been in use in IO modelling (Stone 1961; see also the discussion of the parallel but isolated developments of IO and LCA modelling in Suh et al. 2010). This parallel model structure allows current consequential LCA practice to combine the advantages of both process-based data (high degree of detail) and IO-data (economy-wide completeness).

The increasing global trade and the corresponding availability of geographically differentiated LCA data have increased the relevance of identifying the geographical location of marginal suppliers to the global markets; see examples for aluminium (Schmidt & Thrane 2009), pulp wood (Reinhard et al. 2010), biomass production capacity (Schmidt et al. 2015).

For changes that liberate or bind scarce resources, a consistent analysis requires inclusion of the marginal rebound effects of this change in resource availability (Weidema 2008). The most well-known rebound effect is the effect of price differences that change the availability of money for alternative consumption (see Thiesen et al. 2008 for an example of how to estimate this), but also other rebound effects can be of importance; see Weidema et al. (2008) for an example of systematic inclusion of rebound effects.

Because market reactions to changes in demand and supply can lead to both increases and decreases in environmental impacts, results of consequential studies may often be unexpected and counterintuitive compared to a more static analysis that ignore such market reactions. Examples of such initially counterintuitive and possibly even controversial findings are that:

• Field application and emissions of manure are not related to crop production but related to (caused by) the animal husbandry, and the marginal crop production therefore needs to cover its full fertilisation need by artificial fertilisers exclusively (Dalgaard et al. 2014);
• Bio-based and biodegradable products often have more environmental impact than the fossil-based products they are intended to substitute (Schmidt & Brandão 2013);
• Intensive agriculture and plantation forestry often have less environmental impact than less efficient practices that initially appear more benign (Weidema 2013). An exception is dairy farming where further intensification is harmful due to the reduced displacement of stand-alone high-impact meat production (Weidema et al. 2008).

When specific data used in a consequential model are counterintuitive, controversial, or particularly important for the outcome of the analysis, the requirements to documentation of the data acquisition increases, and additional efforts and techniques may be required for data acquisition, for example the use of equilibrium models to identify the specific farm types that provide the marginal supply of different agricultural products (Jensen & Andersen 2003), and exhaustive uncertainty assessment (Weidema 2011).

Examples of companies that put particular emphasis on open and transparent reporting of the assumptions and data used are Novozymes (see Weidema & Wesnæs 2005, Wesnæs & Weidema 2006) and Arla Foods (Dalgaard et al. 2016). Examples of very structured and well-documented applications of the consequential procedures are Schmidt (2015) for the identification of the determining output of five oil crops and Schmidt et al. (2011) for country-specific consequential electricity mixes. Sharing well-documented consequential data has become easier with the recent availability of the community website consequential-lca.org.

References

Consequential-LCA (2015). The ISO 14040 standards for consequential LCA. http://consequential-lca.org/clca/why-and-when/the-iso-14040-standards-for-consequential-lca/

Dalgaard R, Schmidt J H, Flysjö A (2014). Generic model for calculating carbon footprint of milk using four different LCA modelling approaches. Journal of Cleaner Production 73:146‑153 https://lca-net.com/p/580

Dalgaard R, Schmidt J H, Cenian K (2016). Life cycle assessment of milk ‐ National baselines for Germany, Denmark, Sweden and United Kingdom 1990 and 2012. Arla Foods, Aarhus, Denmark https://lca-net.com/p/2324

Heintz B, Baisnée P-F. (1992). System boundaries. Pp 35-52 in SETAC-Europe: Life-cycle assessment. Brussels: SETAC. (Report from a workshop in Leiden, 1991.12.02-03).

IISI (1997). Methodology report [of the IISI LCI study]. Brussels: International Iron and Steel Institute.

Jensen JD and Andersen M (2003). Marginale producenter af udvalgte landbrugsprodukter. FØI Working paper no. 08/2003 (in Danish). http://curis.ku.dk/ws/files/135447941/8.pdf.pdf

Nielsen A M, Weidema B P (2001). Input/Output-analysis – Shortcut to life cycle data? Proceedings of a workshop held in Copenhagen on the 29th of September 2000. Copenhagen: Danish Environmental Protection Agency. (Environmental Project 581) https://lca-net.com/p/1125

Reinhard J, Weidema B P, Schmidt J H. (2010). Identifying the marginal supply of pulp wood. Aalborg: 2.-0 LCA consultants. https://lca-net.com/p/198

Schmidt J H. (2015). Life cycle assessment of five vegetable oils. Journal of Cleaner Production 87:130‑138. https://lca-net.com/p/1719

Schmidt J H, Brandão M (2013). LCA screening of biofuels – iLUC, biomass manipulation and soil carbon. This report is an appendix to a report published by the Danish green think tank CONCITO on the climate effects from biofuels: Klimapåvirkningen fra biomasse og andre energikilder, Hovedrapport (in Danish only). CONCITO, Copenhagen. https://lca-net.com/p/227

Schmidt J, Thrane M. (2009). Life cycle assessment of aluminium production in new Alcoa smelter in Greenland. Grønlands Hjemmestyre. https://lca-net.com/p/183

Schmidt J H, Merciai S, Thrane M, Dalgaard R (2011). Inventory of country specific electricity in LCA – Consequential and attributional scenarios. Methodology report v2. 2.‑0 LCA consultants, Aalborg, Denmark. https://lca-net.com/p/212

Schmidt J H, Weidema B P, Brandão M (2015). A framework for modelling indirect land use changes in life cycle assessment. Journal of Cleaner Production 99:230‑238 https://lca-net.com/p/1863

Stone, R. 1961. Input-output and national accounts. Paris: Organization for European Economic Cooperation.

Suh S, Weidema B P, Schmidt J H, Heijungs R. (2010). Generalized Make and Use Framework for Allocation in Life Cycle Assessment. Journal of Industrial Ecology 14(2):335-353. https://lca-net.com/p/200

Thiesen J, Christensen T S, Kristensen T G, Andersen R D, Brunoe B, Gregersen T K, Thrane M, Weidema B P. (2008). Rebound Effects of Price Differences. International Journal of Life Cycle Assessment 13(2):104-114. https://lca-net.com/p/169

Thrane M (2004b): Energy consumption in the Danish fishery – Identification of key factors. Journal of Industrial Ecology 8, 223–239.

Weidema B P. (1993). Market aspects in product life cycle inventory methodology. Journal of Cleaner Production 1(3-4):161-166.

Weidema B P (1999a). A reply to the aluminium industry: Each market has its own marginal. Letter to the Editor responding to previously published article on Marginal production technologies for LCI’s. International Journal of Life Cycle Assessment 4(6):309‑310 https://lca-net.com/p/1184

Weidema B P. (1999b). System expansions to handle co-products of renewable materials. Pp. 45-48 in Presentation Summaries of the 7th LCA Case Studies Symposium. Brussels: SETAC-Europe. https://lca-net.com/p/1186

Weidema B P. (2001a). Avoiding co-product allocation in life-cycle assessment. Journal of Industrial Ecology 4(3):11-33. https://lca-net.com/p/1142

Weidema B P. (2001b). Two cases of misleading environmental declarations due to system boundary choices. Presentation for the 9th SETAC Europe LCA Case Studies Symposium, Noordwijkerhout, 2001.11.14-15. https://lca-net.com/p/1131

Weidema B P. (2003a). Market information in life cycle assessment. Copenhagen: Danish Environmental Protection Agency. (Environmental Project no. 863). https://lca-net.com/p/1078

Weidema B P. (2003b). Flexibility for application. Market modelling in LCI databases. Presentation for International Workshop on LCI-Quality, Karlsruhe, 2003.10.20-21. https://lca-net.com/p/1082

Weidema B P. (2008). Rebound effects of sustainable production. Presentation to the “Sustainable Consumption and Production” session of the conference “Bridging the Gap; Responding to Environmental Change – From Words to Deeds”, Portorož, Slovenia, 2008.05.14-16. https://lca-net.com/p/175

Weidema B P (2011). Uncertainty reduction in consequential LCA models. Presentation for the Life Cycle Assessment XI (LCA XI) Conference, Chicago, 2011.10.4‑6. https://lca-net.com/p/208

Weidema B P (2013). Reducing impacts of forestry – the fallacy of low-intensity management. Presentation for 6th International Conference on Life Cycle Management, Gothenburg 2013.08.25‑28. https://lca-net.com/p/229

Weidema B P, Norris G A. (2004). Avoiding co-product allocation in the metals sector. Pp. 81-87 in A Dubreuil: “Life Cycle Assessment and Metals: Issues and research directions.” Pensacola: SETAC. (Proceedings of the International Workshop on Life Cycle Assessment and Metals, Montreal, Canada, 2002.04.15-17). https://lca-net.com/p/1042

Weidema B P, Wesnæs M (2005). Marginal production routes and co-product allocation for alcoholetoxylate from palm oil and palm kernel oil (zip-file). Study for Novozymes. Copenhagen: 2.‑0 LCA consultants. https://lca-net.com/p/1028

Wesnæs M, Weidema B P (2006). Long-term market reactions to changes in demand for NaOH. Study for Novozymes. Copenhagen: 2.‑0 LCA consultants. https://lca-net.com/p/1014

Weidema B P, Frees N, Nielsen A-M. (1999). Marginal Production Technologies for Life Cycle Inventories. The International Journal of Life Cycle Assessment 4(1):48-56. https://lca-net.com/p/1188

Weidema B P, Wesnæs M, Hermansen J, Kristensen T, Halberg N (2008). Environmental improvement potentials of meat and dairy products. Eder P & Delgado L (eds.) Sevilla: Institute for Prospective Technological Studies. (EUR 23491 EN). https://lca-net.com/p/171

Weidema B P, Bauer C, Hischier R, Mutel C, Nemecek T, Reinhard J, Vadenbo C O, Wernet G (2013). Overview and methodology. Data quality guideline for the ecoinvent database version 3. Ecoinvent Report 1(v3). St. Gallen: The ecoinvent Centre. https://lca-net.com/p/234

Natural capital from an LCA perspective

August 2, 2016 by Bo Weidema

Last month, on July 13^th, the Natural Capital Coalition published their Natural Capital Protocol, which is a framework for performing Natural Capital Assessments “designed to help generate trusted, credible, and actionable information that business managers need to inform decisions”.

Natural Capital is defined as “The stock of renewable and non- renewable natural resources (e.g., plants, animals, air, water, soils, minerals) that combine to yield a flow of benefits to people”. These flows can be ecosystem services or abiotic services, which provide value to business and to society, and thus includes the impacts on human capital that go via impacts on natural capital (e.g. clean air). The Natural Capital Protocol thus covers the same issues as traditional biophysical Life Cycle Assessment (see also my March 2015 blog on the terminology of Natural Capital Accounting).
Figure 1.1 from Natural Capital Protocol (2016). Licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

The framework largely follows that of Life Cycle Assessment (LCA), starting with the goal definition in Chapter 2: “Define the objective” including target audience and stakeholder engagement. The scope definition in Chapter 3 covers the determination of the focus (organizational, project or product), the extent of the life cycle perspective (here called “boundary”: cradle-to-gate, gate-to-gate, downstream), the stakeholder perspective (here called the “value perspective”: own business only, society, and/or specific stakeholder groups), type of valuation (qualitative, quantitative, monetary), and “other technical issues”: baselines, scenario alternatives, spatial and temporal boundaries.

The Natural Capital Protocol continues by describing screening (Chapter 4: Which impacts and/or dependencies are material?), inventory (Chapter 5: Measure impact drivers), impact assessment (Chapter 6 on the measurement of state changes, i.e. impacts), valuation (Chapter 7), interpretation (Chapter 8) and taking action (Chapter 9).

The largest difference to LCA seems to be the particular focus on what the Protocol calls Natural Capital dependencies, which is an optional risk assessment of the supply security and liabilities related to use of Natural Capital and the precautionary measures that the business takes to reduce these security and liability issues. Such a risk assessment should be part of normal business practice, but is not part of LCA, while the practical measures taken will be part of a life cycle inventory and the impacts of these measures are thus included in the LCA results.

For people familiar with LCA, the Natural Capital Protocol may not contain much new, but the Protocol is a good, simple introduction to environmental assessment from a business perspective and an important call for business to take action.

Reference:

Natural Capital Protocol (2016). Available: www.naturalcapitalcoalition.org/protocol

Circular economy – where does that leave LCA?

June 22, 2016 by Stefano Merciai

At the end of 2015, the European Commission adopted a Circular Economy Package (European Commission 2015). The intention is to move away from current linear business models (make-use-discard) to a future of circular business models (reduce, reuse, remake, recycle). “Closing the loop” is the objective for the next decades.

The concept of a Circular Economy (CE) is that of maintaining the value of products as much as possible within the economic sphere. Therefore, a lot of attention is on the last stages of the economic processes, i.e. the treatment of waste. Re-use and recycling should gradually phase out landfills and incinerators. At the same time, the residues, which inevitably leave the economic sphere, should be harmless for the environment.

The implementation of a CE is seen as a challenge that will reshape our economies, affecting positively the entire society, from the economy to the social sphere, from the environment to the human wellbeing.

All these objectives can be considered absolutely noble, doubtless. However, some considerations are necessary.

First of all, I think we need to focus on the final aims of the new circular economies. Do we want to eliminate the greenhouse gases emissions? Do we want to reduce the use of land? Do we want to reduce the impact on biodiversity? Do we want to phase out poverty? Etc.

Then, we have to plan the best way to reach our goals.

I’m sure that with adoption of CE principles there would be improvements for the environment and, in general, for the economy with respect to the current situation. Yet, we could put all our attention on some predetermined aspects while excluding some others that could be of equal, or even more, importance. A CE may not necessarily be a dematerialised economy and a focus on recycling may distract from improvements in material efficiency or prevention of by-products generation.

Therefore, how sure are we that a CE is the best way to fulfil all our goals?

Here the LCA community comes into play. LCA is now a mature tool for analysing the environmental impact of anthropogenic processes. LCA has a wider perspective where all the phases of a product life cycle are scrutinized. Searching for crucial hotspots and the comparison of alternative pathways is the daily job of an LCA practitioner.

We therefore welcome the EU Action Plan for the Circular Economy and the political visions for a more sustainable future stipulated in the new EU-legislature. But we encourage the LCA community to contribute to the implementation of CEs, because our knowledge and expertise is needed, now more than ever.

Reference:
European Commission (2015). Press-release: Closing the loop: Commission adopts ambitious new Circular Economy Package to boost competitiveness, create jobs and generate sustainable growth, dec 2. 2015: http://europa.eu/rapid/press-release_IP-15-6203_en.htm