Mobilising climate action with moral appeals in a smartphone-based 8-week field experiment

Effective climate change mitigation requires profound lifestyle changes and citizens' support for transformational climate policies. We present a comprehensive, highly granular, field-experiment dataset of people's self-reported, daily, real-life behaviours measured in CO₂e across six domains, as well as their civic and political behaviour. The data (<i>N</i> = 156, 7615 repeated observations over 8 weeks) was collected via a bespoke smartphone app and is enriched by people's daily reflections on their change trajectories and by data on political leaning, emotions, agency, socio-demographics, values, attitudes and social norms. The study shows that exposing people to moral appeals results in overall carbon footprint reduction (particularly from heating, food and consumption), and in greater civic and political climate action, including among people leaning politically to the centre and right. However, the treatment could lead to some backlash, i.e. increased carbon footprint (particularly from food and car journeys) in people who hold egoistic values.