Behavioural Science for Climate Change Adaptation

The report analyzes a failed government-led project to plant vetiver grass for erosion control in Fiji, identifying six behavioural drivers—salience of loss, choice uncertainty, outcome efficacy, collective efficacy, self-efficacy, and material access—that influence adoption. It argues that top-down interventions often fail because they overlook psychological and socio-cultural drivers, recommending that future climate adaptation projects integrate behavioural science and deep community engagement during the design phase.

• A government-led project between 2018 and 2020 to plant vetiver grass in the villages of Naveiveiwali, Malabe, and Nabouva failed to achieve sustained adoption; by 2023, direct observation showed "no uptake of the vetiver along the riverbanks" and most plants had been "washed away".
• The failure of the intervention is attributed to a design that targeted only two behavioural drivers—material access and self-efficacy—through one-off provisions of seedlings and rudimentary training, while ignoring four other critical drivers: salience of loss, outcome efficacy, collective efficacy, and choice uncertainty.
• Despite high 'salience of loss'—where villagers expressed strong emotional attachment to land and viewed erosion as a loss of "cultural identity"—this driver alone was insufficient to motivate the adoption of vetiver grass.
• Outcome efficacy was hindered by 'confirmation bias' and a lack of 'social proof', as villagers focused on past failures where vetiver was washed away and expressed a lack of interest because they "haven’t seen evidence yet that it works".
• Gender inequality in project implementation limited the success of the intervention; women, who are "key custodians of the riverbanks", were excluded from awareness-raising sessions and instead "organized the catering for those involved in the planting".
• Collective efficacy was undermined by 'pluralistic ignorance', where 93% of surveyed respondents believed the community should plant vetiver, but only 59% believed others in the community expected them to do so.
• The study demonstrates that the process of behavioural data collection itself can act as an intervention; after the 2023 study, field experts observed in 2024 that awareness had increased and some villagers had started collecting seeds from neighbouring villages.

APA

Dekens, J., Bujold, P., & Mannle, K. (2024). Behavioural Science for Climate Change Adaptation. International Institute for Sustainable Development. https://www.iisd.org/system/files/2024-08/behavioural-science-climate-change-adaptation-fiji.pdf

Chicago

Dekens, Julie, Philipe Bujold, and Kate Mannle. Behavioural Science for Climate Change Adaptation. International Institute for Sustainable Development, 2024. https://www.iisd.org/system/files/2024-08/behavioural-science-climate-change-adaptation-fiji.pdf.

Wikipedia

{{cite report |last1=Dekens |first1=Julie |last2=Bujold |first2=Philipe |last3=Mannle |first3=Kate |title=Behavioural Science for Climate Change Adaptation |publisher=International Institute for Sustainable Development |date=July 2024 |url=https://www.iisd.org/system/files/2024-08/behavioural-science-climate-change-adaptation-fiji.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{dekens2024behavioural, author = {Dekens, Julie and Bujold, Philipe and Mannle, Kate}, title = {{Behavioural Science for Climate Change Adaptation}}, institution = {International Institute for Sustainable Development}, year = {2024}, month = jul, url = {https://www.iisd.org/system/files/2024-08/behavioural-science-climate-change-adaptation-fiji.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }