Drivers and barriers of sustainable behaviours among young generations in a climate-vulnerable Italian city

Sustainable behaviours are essential for addressing climate change, particularly as extreme weather events intensify globally. Identifying the factors that drive or hinder these behaviours is crucial for developing effective interventions. However, existing behavioural models often overlook cultural, social, and contextual influences shaping sustainable actions, especially in climate-vulnerable regions. The COM-B model is a behavioural framework that explains behaviour change through the interplay of Capability, Opportunity, and Motivation, which together determine whether a Behaviour can occur. In this study, we apply it—among its first uses in climate change research—to analyze the determinants influencing sustainable behaviours. Conducted in Chiavari, a Ligurian city prone to floods, the research involved 470 secondary school students (aged 15–17) and 117 young adults (aged 18–35). Results show that young adults with direct experience of extreme events exhibit greater climate awareness (90 % vs. 80 % of students) and a higher tendency to engage in sustainable behaviours, while students demonstrate a stronger belief in the effectiveness of collective action. The analysis highlights moderate positive correlations between motivation and sustainable behaviour, as well as between capability and both motivation and behaviour, emphasizing capability's key role in fostering motivation. However, over 40 % of respondents feel no social pressure to reduce their footprint, and only 15.7 % of students and 18.8 % of young adults prioritize ethical and sustainable consumption. These findings reinforce the COM-B model's potential to identify the most effective determinants for fostering sustainable behaviours. Targeting capability and motivation could enhance interventions, leveraging local awareness and direct experiences to promote climate-conscious actions. • Among the first applications of the COM-B model in climate change research. • Positive correlations between capability, opportunity, motivation, and behavior. • Sustainable behaviors are crucial for addressing the climate change challenges. • Needs of community-driven plans to foster collective action toward sustainability. • Experience on climate extreme events influences adoption of sustainable behaviors.