The shift toward the adoption of sustainable lifestyles may be achieved with the support of environmental indicators, such as those obtained from Life Cycle Assessment (LCA). The aim of this paper was to perform a Consumer LCA of the potential environmental impacts of mobility habits of a generic consumer. This study also proposed a methodology for analyzing life cycle impact assessment (LCIA) results called Marginal Variation on Impact Assessment (MVIA). Mobility habits in lifestyles were modeled considering transportation to short and long-distance travels. The mobility alternatives considered were travel on foot, by bicycle, car (private and shared), bus, and airplane. Linear regression was applied to identify the marginal variation in aggregated single score results of transportation habits. Mobility with a private car had the highest environmental impact, whereas the use of a bus, bicycle and walking were the most sustainable alternatives. The results exhibited sensitivity to car-sharing. Taking flights for longdistance travels resulted in higher environmental impacts than other alternatives. Marginal Variation on Impact Assessment indicated that the consumer may find the greatest potential to change behavior and reduce impacts in mobility habits related to short-distance travels as well as by reducing the frequency of long-distance travels. The proposed MVIA methodology fits as a tool to support environmental life cycle impact assessment.

Introduction

The transport sector is a hotspot accounting for about 14% of greenhouse gas emissions (IPCC, 2014) and 24% of carbon dioxide emissions from fuel consumption (IEA, 2017). Nonetheless, there is still a growing demand for passenger commuting and alternatives of mobility, especially in developing countries (Dalkmann and Huizenga, 2010). In addition, there is a need for more sustainability in transportation, which is determined by factors like the availability of appropriate transportation infrastructure (Chiou et al., 2013), the promotion of sustainable consumer policies (Thøgersen, 2005), and a shift on transportation habits by consumers (Young et al., 2010). In turn, decision-makers are faced with the challenge of ensuring a larger capacity of transport systems, as well as to meet the consumer demands for more sustainable alternatives of mobility (United Nations Environment Programme, 2016). How lower would be individual environmental impacts by sharing a car when going to work? If doing so rather than taking a bus, would a consumer increase his or her own environmental footprint? In this sense, a consumer might wonder: what mobility alternatives would be more sustainable? The aim of this study is to perform a Life Cycle Assessment (LCA) to analyze the potential environmental impacts of mobility habits of a generic consumer. Therefore, we aim to provide real consumers with information supporting a more sustainable change in lifestyles, as well as to back-up decision-makers to evaluate more precisely what aspects should be prioritized when formulating policies for sustainable consumption.