Through their consumption behavior, households are responsible for 72% of global greenhouse gas emissions. Thus, they are key actors in reaching the 1.5°C goal under the Paris Agreement. However, the possible contribution and position of households in climate policies is neither well understood, nor do households receive sufficiently high priority in current climate policy strategies. This paper investigates how behavioral change can achieve a substantial reduction in greenhouse gas emissions in European high-income countries. It uses theoretical thinking and some core results from the HOPE research project, which investigated household preferences for reducing emissions in four European cities in France, Germany, Norway and Sweden. The paper makes five major points: First, car and plane mobility, meat and dairy consumption, as well as heating are the most dominant components of household footprints. Second, household living situations (demographics, size of home) greatly influence the household potential to reduce their footprint, even more than country or city location. Third, household decisions can be sequential and temporally dynamic, shifting through different phases such as childhood, adulthood, and illness. Fourth, short term voluntary efforts will not be sufficient by themselves to achieve the drastic reductions needed to achieve the 1.5°C goal; instead, households need a regulatory framework supporting their behavioral changes. Fifth, there is a mismatch between the roles and responsibilities conveyed by current climate policies and household perceptions of responsibility. We then conclude with further recommendations for research and policy.

The Brundtland Commission report ‘Our Common Future’ highlighted that residents in high-income countries lead lifestyles incompatible with planetary boundaries. Three decades later, consumption-related greenhouse gas (GHG) emissions have continued to increase. To achieve ‘well below 2°C’ and 1.5 °C goals, consumption-related emissions must be substantially reduced in the coming decades. This paper provides insights on how to pursue 1.5 °C pathways through changes in household consumption. It draws on original data gathered in the project ‘HOusehold Preferences for reducing greenhouse gas Emissions in four European High Income Countries’ (HOPE) to analyse policies targeting and affecting direct and indirect GHG emissions in three household consumption categories (mobility, housing and food) in four countries (France, Germany, Norway and Sweden) and four medium-sized cities. This paper demonstrates discrepancies and similarities between current governmental policy approaches in the four countries and household perceptions of consumption changes with respect to policy mechanisms, responsibilities and space for acting on mitigation. Current demand-side policy strategies rely heavily on instruments of self-governance and nudging behaviour. Whilst some of our data suggests that households broadly accept this, it also suggests that governments could more actively lead and steer demand-side mitigation via adjusting and supplementing a comprehensive list of 20 climate policy measures currently in place in one or more of the case countries. The paper concludes by suggesting areas for more effective policy change and household-level climate change mitigation to feed the next update of climate pledges under the Paris Agreement.

This paper investigates households’ preferences to reduce their carbon footprint (CF) measured in carbon dioxide equivalents (CO2e). It assumes that a substantial CF reduction of households is essential to reach the 1.5 ◦C goal under the Paris Agreement. Data was collected in four mid-size cities in France, Germany, Norway, and Sweden. Quantitative data was obtained from 308 households using a CF calculator based on a questionnaire, and a simulation game. The latter investigated households’ preferences when being confronted with the objective to reduce their CF by 50 percent by 2030 in a voluntary and forced scenario. Our results show that the greater the CO2e-reduction potential of a mitigation action, the less willing a household was to implement that action. Households preferred actions with moderate lifestyle changes foremost in the food sector. Voluntarily, households reached a 25% footprint reduction by 2030. To reach a substantial reduction of 50 percent, households needed to choose actions that meant considerable lifestyle changes, mainly related to mobility. Given our results, the 1.5 ◦C goal is unlikely to be realizable currently, unless households receive major policy support. Lastly, the strikingly similar preferences of households in the four European cities investigated seem to justify strong EU and international policies.

Background: It is now universally acknowledged that climate change constitutes a major threat to human health. At the same time, some of the measures to reduce greenhouse gas emissions, so-called climate change mitigation measures, have significant health co-benefits (e.g., walking or cycling more; eating less meat). The goal of limiting global warming to 1,5° Celsius set by the Conference of the Parties to the United Nations Framework Convention on Climate Change in Paris in 2015 can only be reached if all stakeholders, including households, take actions to mitigate climate change. Results on whether framing mitigation measures in terms of their health co-benefits increases the likelihood of their implementation are inconsistent. The present study protocol describes the transdisciplinary project HOPE (HOuseholds’ Preferences for reducing greenhouse gas emissions in four European high-income countries) that investigates the role of health co-benefits in households’ decision making on climate change mitigation measures in urban households in France, Germany, Norway and Sweden.

Methods: HOPE employs a mixed-methods approach combining status-quo carbon footprint assessments, simulations of the reduction of households’ carbon footprints, and qualitative in-depth interviews with a subgroup of households. Furthermore, a policy analysis of current household oriented climate policies is conducted. In the simulation of the reduction of households’ carbon footprints, half of the households are provided with information on health co-benefits of climate change mitigation measures, the other half is not. Households’ willingness to implement the measures is assessed and compared in between-group analyses of variance.

Discussion: This is one of the first comprehensive mixed-methods approaches to investigate which mitigation measures households are most willing to implement in order to reach the 1,5° target set by the Paris Agreement, and whether health co-benefits can serve as a motivator for households to implement these measures. The comparison of the empirical data with current climate policies will provide knowledge for tailoring effective climate change mitigation and health policies.