Exploring carbon footprint reduction pathways through urban lifestyle changes: a practical approach applied to Japanese cities

Abstract

Cities and urban consumers play a central role in the transition to a decarbonized society. Building on existing studies that identify the significant contributions of lifestyle changes, this study proposes a practical methodology for modeling and exploring city-specific carbon footprint reduction pathways through lifestyle changes to decarbonization. It uses an input–output approach with mixed-unit consumption data and the concept of adoption rates, which is applicable to multiple cities with widely available subnational household consumption data. This paper illustrates the use of this methodology by exploring the consumption-based mitigation pathways of 52 Japanese cities with 65 lifestyle change options covering mobility, housing, food, consumer goods, and leisure domains. The results revealed that city-specific impacts of a variety of lifestyle change options can differ by as much as a factor of five among cities, even in the urban context within the same country. Due to this city-level heterogeneity, the priority options of decarbonized lifestyles, such as among shared mobility, low-carbon diets, and longevity of consumer goods, have shifted between cities. The analysis suggests that ambitious urban lifestyle changes can potentially reduce their carbon footprints to meet the 1.5 °C target. However, due to the overlaps of mitigation potentials between multiple lifestyle change options, the necessary levels of adoption and coverage are extensive (i.e. adoption rates of 0.6–0.9). Importantly, adopting lifestyle changes with an efficiency strategy (e.g. the introduction of end-use technologies) or sufficiency strategy (e.g. behavioral changes in consumption amounts and modes) alone is not enough; the only way to succeed is through the combination of both strategies. This paper calls for a target-based exploration and identification of city-specific priorities of lifestyle change options to facilitate consumption-oriented mitigation policies and stakeholder actions to address the climate impacts of urban consumption.

Too much consumption or too high emissions intensities? Explaining the high consumption-based carbon footprints in the Nordic countries

“…We also chose the target levels to comply with our footprints' scope. The scope differences are the main reason why average per capita footprints in our sample are lower than those reported in previous studies in the Nordics: 12.2 to 15.2 t CO 2 e in Denmark (Hertwich, Peters 2009, Ivanova et al 2016, 8.88 to 18 t CO 2 e in Finland (Hertwich, Peters 2009, Ala-Mantila et al 2016, Ivanova et al 2016, Salo and Nissinen 2017, Koide et al 2021a, 10.4 t CO 2 e in Iceland (Clarke et al 2017), 10.3 to 14.9 t CO 2 e in Norway and 8.7 to 10.5 t CO 2 e for Sweden (Hertwich, Peters 2009, Ivanova et al 2016. Other reasons include the changes in carbon intensities and consumption patterns since the other studies were conducted, as well as potentially higher adoption rates of the demand-side actions in our sample than in whole societies.…”

“…We also highlight that it takes multiple behavior changes to bring a personal carbon footprint to the target levels. Other research in affluent countries has reached the same conclusion, adding that high adoption rates are necessary to reach the targets at societal scales (Akenji et al 2021, Koide et al 2021a.…”

“…The consumption-based carbon footprints have been extensively utilized for studying the opportunities for emission reductions via lifestyle changes, particularly in the recent years (Jones and Kammen 2014, Vita et al 2019, Ivanova et al 2020, Koide et al 2021a, 2021b. These studies have quantified the reduction potentials associated with numerous lifestyle changes (e.g.…”

Extension and update of multiscale monthly household carbon footprint in Japan from 2011 to 2022

“…On this basis, the household sector concurrently holds a crucial bearing on achieving emission reduction objectives and has considerable mitigation potential 47 , 48 . Evidence has demonstrated that seemingly trivial day-to-day actions, such as reducing water usage, turning off lights when not in use, and proper waste disposal, carry weight 49 – 52 . Therefore, this dataset focuses on the carbon footprint of Japan’s households, aiming to contribute to the body of knowledge that guides emission reduction strategies from the household perspective.…”

Zero carbon transitions: a systematic review of the research landscape and climate mitigation potential

“…Brand et al (2020) highlight this in improved road safety and transport equality from the uptake of shared and multi-modal mobility, Costa et al emphasise the reduced pressure on natural resources, and Garvey et al (2021) the public health benefits of low-carbon dietary transitions. Multiple studies (Koide et al, 2021;Wiest et al, 2022) also addressed the feasibility of bringing about such change. The former showed that the needed uptake of behavioural changes to meet net-zero ranged from 62% to 87% of the population in a study covering 52 Japanese cities, while the later concede that it is unrealistic for all European citizens to adopt their proposed lifestyle changes.…”