Niveles de implicación de las diferentes entidades promotoras Conclusiones

Life cycle thinking is a method to evaluate the impacts of activities that have an effect on the environment from a holistic view. The aim is not just to improve the ecological footprint, but also to have a better indication of the socio-economic performance throughout the life cycle of the product or processes. Environmental Life Cycle Assessment (LCA) method is the most established and widely used life cycle thinking approach since 1970s (Guinée et al., 2011). Over the past four decades, there have been a range of life cycle thinking methods developed from the standard LCA including Life Cycle Costing (LCC), Social Life Cycle Assessment (SLCA), and Life Cycle Sustainability Assessment (LCSA) (Guinée et al., 2011; Klöpffer, 2003).

The Society of Environmental Toxicology and Chemistry (SETAC) has played a major role in the development of LCA (Andersson et al., 1998; Bretz, n.d.; Klöpffer, 2006; Todd et al., 1999). The LCA method is carried out in accordance with the ISO 1404X standards (ISO, 2006). According to the method outlined, LCA involves four main iterative processes: goal and scope definition, inventory analysis, impact assessment, and interpretation (ISO, 2006). Different products can be compared based on the same functional unit. LCA identifies the input and output of vehicle inventories in each life cycle stages and then, evaluates the potential environmental impact accordingly. The analysis allows manufacturers to make better informed decisions and assists government in automotive-related legislations or policies (Finnveden, 2000; Klöpffer, 2003). Furthermore, trade-offs between the various life cycle stages can be assessed to understand the environmental impact with respect to each phase. It is important to note that the scope, assumptions, limitations, and steps taken at each life cycle stage must be outlined clearly in the methodology to ensure adequate description of the product systems to address the objective of the study.

The growing importance of the three pillars of sustainability: environment, social, and economy has led to the broadening of standard LCA scope (Heijungs et al., 2010; Jeswani et al., 2010). LCC method is used to estimate the economic cost of a product during the entire life cycle in order to assist in decision-making relating to cost- effectiveness (Kloepffer, 2008; Swarr et al., 2011). To assess the social impacts of a product that are not currently addressed in LCA, such as work conditions, labour practices, and product responsibility, SLCA method is established (Benoît et al., 2010; Jørgensen et al., 2008). LCSA method is introduced to cater for a more holistic

sustainability assessment framework. It is a combination of the LCA, LCC, and SLCA methods to account for the environmental, social, and economic performances of a product (Finkbeiner et al., 2010; Kloepffer, 2008; Zamagni, 2012). The expansion of LCA through LCC, SLCA, and LCSA is in accordance with the general methodological framework for LCA although they are not standardised (Guinée et al., 2011; Swarr et al., 2011). One of the main barriers in performing the assessment through these life cycle thinking methods is the lack of data availability (Jeswani et al., 2010; Jørgensen et al., 2008). Therefore, the LCA method is still the most widely used tool in industry since its database and practice are well established.

Automotive manufacturers often use LCA method to assist in decision-making with respect to the entire life cycle: material extraction, production, use, and EoL phases. It is used to assess the environmental footprint of vehicles, and allow modifications for new vehicle designs at earlier phases to improve the environmental impact for different life cycle stages. The research themes for some of the previous automotive LCA studies focusing on the respective phase are summarised in Table 2-15.

Table 2-15: Categorisation of past automotive LCA studies based on the research themes for the respective LCA phases.

LCA Phase Research Theme References

Production Material selection for lightweight vehicle/vehicle part/vehicle structure

(Pryshlakivsky and Searcy, 2017; Tharumarajah and Koltun, 2007)

Use Alternative fuels/powertrain technologies for vehicle

(MacLean and Lave, 2003; Moro and Helmers, 2017; Nicolay et al., 2000; Spielmann and Althaus, 2007)

EoL Adoption of different recycling processes and waste treatment scenarios

(Belboom et al., 2016; Ciacci et al., 2010; Passarini et al., 2012)

EoL Material selection for

vehicle/vehicle parts/vehicle structure

(Badino et al., 1997; Dos Santos Pegoretti et al., 2014; Ehrenberger and Friedrich, 2013; Passarini et al., 2012)

Entire life cycle

Table 2-15 (Continued)

LCA Phase Research Theme References

Entire life cycle

Material selection for lightweight vehicle/vehicle part/vehicle structure (BIW)

(Alonso et al., 2007; Bonollo et al., 2013; Das, 2011, 2000; Dhingra and Das, 2014; Fuchs et al., 2008; Mayyas et al., 2012; Nanaki and Koroneos, 2012; Puri et al., 2009; Ribeiro et al., 2007; Schmidt et al., 2004; Sun et al., 2017; Witik et al., 2011)

Entire life cycle

Assessment of an average passenger vehicle/vehicle part/vehicle structure for specific period or country

(Castro et al., 2003; Dos Santos Pegoretti et al., 2014; Koffler, 2014; Messagie et al., 2010; Schmidt, 2006; Schmidt et al., 2004; Subic et al., 2010; Subic and Francesco, 2006; Sullivan et al., 1998)

Entire life cycle

Alternative fuel/powertrain technologies for vehicle

(Hawkins et al., 2013; Helmers et al., 2017; MacLean et al., 2000; Messagie et al., 2010; Nemry et al., 2008)

Entire life cycle

Climate change impact of material selection for vehicle

(Danilecki et al., 2017; Dhingra and Das, 2014; Geyer, 2008;

Hakamada et al., 2007; Kim et al., 2010; Saur et al., 2000; Song et al., 2009; Sullivan et al., 1998;

Ungureanu et al., 2007)

In previous studies, the vehicle use phase has been identified as the major contributor to the total environmental impact due to the CO2 emissions and fuel

consumption (Das, 2000; Mayyas et al., 2012; Puri et al., 2009; Schmidt et al., 2004; Sullivan et al., 1998). Consequently, vehicle manufacturing design has focused towards lightweight materials with the aim to improve fuel efficiency during use phase besides increasing the recyclability of materials during ELV to optimise the overall environmental performance. Most of the studies, therefore, are centred around material selection or substitution to improve the vehicle’s carbon footprint. This highlights the importance of understanding the side effects of this focus on other environmental impact categories. Nemry et al. (2008) have carried out life cycle analysis for mass-reduced vehicles based

on a reference passenger car. They have shown that there is an increasing trend of waste produced despite the decreasing environmental impacts in GWP and primary energy consumption (Nemry et al., 2008).

A simplified vehicle LCA study based on historical material composition trend over time was carried out by (Soo et al., 2015), and the results are shown in Figure 2-19. There is a decreasing trend of GWP and resources consumption from 1980 to 2010 due to the fuel efficiency improvement in newer vehicle designs. In contrast, the waste category indicated an increasing trend. The outcomes are consistent with the findings from Nemry et al. (2008).

Figure 2-19: Normalised result for resources, GWP, and waste categories for a vehicle made in respective years based on EDIP 1997 and EDIP 2003 v1.04 (Soo et al., 2015).