Late adolescence as a moment of change for pro-environmental behaviour
: (Alternative Format Thesis)

  • Kaloyan Mitev

Student thesis: Doctoral ThesisPhD


Climate change is amongst the most serious issues faced by modern society. Slowing down climate change requires urgent action, for example breaking old habits and engaging new pro-environmental behaviours. Research in the domain of environmental psychology has showed that during certain periods of people’s lives, i.e. moments of change (MoC), it could be easier to acquire new habits due to changes in the contextual and social cues. The present thesis explored the effects of two moments of change on the pro-environmental behaviours of young people currently in their late adolescence. The focus was on a planned MoC (the transfer from school to university) and an unplanned MoC (the COVID-19 pandemic). Four empirical studies were conducted to answer the following objectives: 1) if and how do young people’s pro-environmental behaviours change when going through a moment of change, 2) how can we use moments of change to strengthen the effects of interventions, and 3) how do planned and unplanned moments of change differ in their effects on habit disruption and pro-environmental behaviour change.

In Study 1, a survey with first-year university students in the UK was conducted exploring their pro-environmental behaviours before and after starting university. Findings demonstrated that the start of university was associated with a positive change in domestic and travel pro-environmental behaviours, as well as meat/fish consumption. However, there were negative effects on pro-environmental consumption behaviours and levels of environmental activism. In addition, self-transcendence values and self-evaluated environmental knowledge were associated with pro-environmental behaviours. In Studies 2 and 3, an intervention was designed combining an informational element with a self-affirmation or a self-reflection exercise. Taking part in the intervention six to seven months the start of university revealed a positive effect on food waste as well as meat consumption, but the latter was relevant only for people with higher self-efficacy levels.

In Study 4, another survey with young people across the UK was conducted which looked at behaviours before and after the start of the COVID-19 pandemic. Results showed that the COVID-19 pandemic and its restrictions were associated with higher engagement in active travel and lower consumption of animal products. However, levels of environmental activism registered a decline. In Study 5, the previously mentioned intervention design was applied, however, using the end of the COVID-19 restrictions in 2021 in the UK as a MoC. It was successful at sustaining food waste levels for people with lower levels of collective efficacy. In addition, older participants in our sample, consisting of people aged between 16 and 24 years, were more likely to sustain their consumption of ethical/green products.

The results from the five empirical studies in this thesis emphasise the effects of an underexplored planned MoC and a novel unplanned MoC on pro-environmental behaviours during a crucial developmental period, i.e. late-adolescence. They also highlight the successful application of pro-environmental behaviour change interventions during moments of change. This could be useful for policymakers as well as stakeholders working towards tackling climate change and other environmental issues. They could use moments of change to develop programmes and interventions aimed at increasing young people’s engagement with pro-environmental behaviours.
Date of Award28 Jun 2023
Original languageEnglish
Awarding Institution
  • University of Bath
SupervisorLorraine Whitmarsh (Supervisor), Merideth Gattis (Supervisor) & N C Nash (Supervisor)


  • Climate Change
  • behavioural science
  • life transitions
  • Late Adolescent
  • pro-environmental behaviour
  • moments of change
  • Behaviour change
  • young people

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