Policies addressing climate change adaptation should account for behavioural factors

News - 24 October 2023 - Webredactie

This summer we all witnessed the scale of damages that climate-induced hazards such as heavy rainfall, floodings and landslides can bring upon people and cities. Adaptation to these hazards is pivotal, and both governments and homeowners can take actions. In scientific models used to support policy-decisions on climate change it is assumed that inhabitants make rational decisions and act as soon as it becomes economically-beneficial for them. Yet, in practice adaptation uptake is slow, and people take less-effective actions than would be optimal for them. New research carried out by TU Delft researchers Alessandro Taberna and Tatiana Filatova has taken into account this adaptation deficit. It highlights the importance of considering behavioural biases and social influence when studying individual adaptation choices. The paper has been published in the renowned journal Proceedings of the National Academy of Sciences (PNAS).


Filatova: ‘While most of the scientific decision support tools focus on estimating the consequences (costs/benefits) of government-led adaptation, a lot of damages can be prevented if people take actions. And they do. However, in the scientific models used to support policy-decisions this is rarely accounted for.’ The main challenge has always been in the fact that it is difficult to model behaviourally-rich representation of human decisions in computational models. ‘This research shows how advanced research methods in this domain have become’, she continues.


Too little, too late

For the first time researchers have quantified the so called “adaptation deficit” – lower uptake of adaptation by homeowners than would be optimal (i.e. economically efficient), by explicitly accounting for different ‘soft’ adaptation constraints like (lack of) awareness about hazards, biases in perceived efficacy of different measures and social influence. ‘Private actions could reduce up to 50-70% of residual damages but they don’t because people take actions too late or too little, if they behave as they report in the surveys’, Taberna states.

The outcomes of our study reveal that policies addressing climate change adaptation should account for diverse behavioural factors such as worry and social influences, and design tailored policies such as offering subsidies to low adaptive capacity households and increasing awareness for medium adaptivity capacity households. Instead, factors that were traditionally considered important – number of exposed people and objective effectiveness of private measures – appear to be less important than behavioural biases. There is increasingly more data about what influences human behaviour, and this innovative approach allows accommodating a more comprehensive understanding of human behaviour in addition to purely economic considerations.


Unexplored territory
The extent of uncertainty of various social-behavioural factors such as worry about hazards, or social influence, in addition to the traditional considerations of costs and effectiveness of various private adaptation measures (such as flood-proofing your home) has been unexplored according to Filatova. ‘Our article takes a large leap forward and systematically uses behavioural survey data, theories from environmental psychology, and global sensitivity analysis to explore how, when and which households can take climate adaptation action, and how it links to the overall performance of the regional economy (for example interacting with unemployment and so on).’ The research also explicitly shows that people with high adaptive capacity (education & income) benefit most from private adaptation. Middle adaptive capacity households already have some valuable assets to loose and enough means to invest in adaptation, but postpone it due to lacking awareness about flood risks and non-supportive social norms.  People with low adaptive capacity either buy less-effective adaptation measures or delay the action, which sends them in the downward spiral of repetitive losses. The researchers also estimate regional damages with and without private adaptation, under different assumptions about human behaviour. This ERC-funded research on climate-induced floods in coastal cities (Miami in this article) focuses on the difference private bottom-up actions can make.


According to Taberna and Filatova this research is crucial because it challenges the traditional assumption employed in policy-making that people make rational decisions when dealing with climate change. It highlights the importance of considering behavioural biases, which are often overlooked in climate adaptation policies. ‘A policy that considers these behavioural aspects might involve community engagement and awareness campaigns to encourage climate adaptation behaviour, hence reducing costs of climate change on the society’, they conclude.