*3.1. Structuring Findings*

For the purpose of this paper, the choice of how to structure sustainable lifestyles elements of NDCs was made with the aim of (1) providing insights into how NDCs and relevant climate change policies refer to low-carbon lifestyles, and (2) supporting the identification of the type of lifestyle changes missing from NDCs that could contribute significantly to the additional climate change reductions needed to remain within the 1.5-degree target.

First a distinction was made between five categories—housing, mobility, food, goods/ waste, and leisure—in line with Section 2.1.3. Within each category, mitigation measures that would satisfy the criteria of Creutzig et al. [28] in Section 2.1.6 were included, in the sense that they had to involve a decision by a consumer or an otherwise involuntary change in their life. This extended more broadly than the criteria of Moran et al. [29], because their classification focused on present-day possibilities, whereas NDCs and climate change mitigation strategies are planned to 2050, thereby including options not ye<sup>t</sup> available or requiring initial investment in infrastructure by government. Two further categories were then added, one reflecting SCP 3.0 approaches (infrastructure, social norms, sufficiency, lifestyles) in line with Section 2.1.5, and a category for special references to extraterritorial emissions.

### *3.2. Results of the Policy Review*

The table in the Note Information outlines which countries included sustainable lifestyles in their NDCs or national climate change policies, and attempts to distinguish between territorial emissions, which are within the scope of the Paris Agreement, and non-territorial emissions (or footprints), which are not directly included ye<sup>t</sup> in reporting but referred to in the IPCC reports as necessary to mitigating climate change.

We make four general observations. First, all NDCs reviewed included housing and/or mobility, and therefore did touch on sustainable lifestyles. Most NDCs cover building energy efficiency, many cover public transport. Increasingly, they also cover indirect emissions, such as from food and consumer goods. The circular economy is also emerging as a cross-cutting strategy with many consumer-facing implications. Second, some NDCs or national climate change policies go further to mention reducing consumption, particularly reducing transport consumption through flexible work policies and urban planning, food waste prevention, and switching to share economy systems over personal ownership. Thirdly, several specifically include references to carbon footprinting (Switzerland, France, Japan, Republic of Korea), which was also included in the IPCC AR5 (though omitted from the summary for policymakers). Last, policies released most recently are more likely to include lifestyles, possibly due to the findings of the IPCC 2018 special report. There are exceptions, including China and Japan. In China's case, 85% of its carbon footprint is domestic, therefore the motivation may be to reduce territorial emissions, and remain within carrying capacity of its own environmental systems. In Japan's case, there is a larger footprint abroad, therefore the motivation may be based on common but differentiated responsibility.

More specific observations are listed in Table 2.


**Table 2.** Summary of findings: four different levels of inclusion of sustainable lifestyles in climate policy.
