How a changing climate is changing behavior

Abstract

Floods appear in many of the world's oldest stories (i.e. Noah and the Arc in the Abrahamic religions, Manu in Hinduism, and the Gun-Yu myth in Chinese mythology). When observed historically, they often have an element of mysticism about them, symbolizing eradication and rebirth. In the present, however, there is little that is mystical about the devastation brought on by floods as they cause more destruction annually than any other hazard. With much of the modern development taking place along the coast or near riverways, assets and livelihoods are increasingly concentrated in exposed areas. By-products of climate change such as sea level rise and extreme precipitation events increasingly devastate these regions; with the projection that the risk of floods will continue to increase in the future.

Top-down, government-led adaptation to floods on its own cannot contend with growing risk; rendering household participation essential. Governments, risk modelers, scientists, and other interest groups (i.e. NGOs) need a solid understanding of household behavior in order to formulate strategies and engage stakeholders across scales to address climate-induced risks. This dissertation devotes its attention to better understanding households' perceptions, intentions, and behavioral drivers and their dynamics, concerning floods in various social, geographical, cultural, and environmental contexts. More concretely, the principal research objective of this dissertation is:

To progress toward an understanding of how households perceive, are affected by, and adapt to floods in various contexts over time.

Following a comprehensive review and analysis of prior empirical research on household flood adaptation, this dissertation presents the analysis of a panel survey carried out between 2020-2021 aimed at collecting data to tackle the aforementioned objective. Focusing on large urban centers in the United States, China, Indonesia, and the Netherlands I use various statistical techniques and methods to analyze the survey data and study a range of aspects from household perceptions as they concern floods and climate change, to reported adaptation behavior. The survey solicits information on 18 adaptation measures that range from inexpensive, actions that do not require considerable effort (i.e. having an emergency preparedness kit, emergency coordination with one's neighbor, etc.), to costly measures that require a substantial time investment (i.e. elevating one's home, waterproofing one's windows, etc.)

In analyzing how household adaptation decisions are influenced, depending on the extit{type} of measure and the context in which the household resides, this dissertation offers insight into which socio-behavioral drivers and barriers of household adaptation are generic and those which may vary depending on the institutional and environmental conditions. A household's perceived ability to cope, and the emotion, ``worry,'' plays a substantial role in driving household adaptation intention. In contrast, the financially calculated risk-based drivers: the perceived probability of a flood happening and the perceived damage should a flood occur, generally have a more subdued effect on household adaptation intentions. This is related to the fact that not all households have sufficient capacity or awareness to subjectively assess the probability and damage of a potential flood. Individual risk-uncertainty - a trait more frequently found in populations historically more vulnerable to floods (i.e. women and lower educated) has a large detrimental effect on households' intention to pursue flood adaptation measures.

While internal perceptions are critical to consider, external factors can have an equally potent role in affecting household adaptation behavior. I examine the effect of context at multiple scales in this dissertation, assessing the role of social expectations, perceptions of government measures, and national culture on household adaptation decisions. Households use their observations of what others (i.e. their social network, the government) are doing with respect to flood adaptation, to inform their decisions. The degree to which both external and internal factors influence household adaptation decisions can differ based on the cultural and geographical context. Various factors have a weaker or stronger influence and at times even the opposite effect on adaptation behavior, depending on where the household resides.

While internal and external perceptions are requisite considerations in understanding household behavior, it is likewise crucial to account for experiences and the co-benefits of various household adaptive actions. The effects of prior flood experiences and the benefits of taking adaptations together are additional key considerations when studying household flood adaptation, due to the economic benefits that can arise from undertaking measures together. Furthermore, prior experience with floods can motivate adaptation behavior, but substantial financial damage from a flood impedes a household's adaptation intention; as their focus is on recovery, not adapting.

The findings in this dissertation are of use to scientists, modelers, risk specialists, and policymakers; whether they are designing models, a communication strategy, or a policy aimed at encouraging household action. With the effects of climate change increasingly affecting communities across the globe, households are having to contend with hazards that are more extreme and frequent than in the living memory of humanity. Unless immediate action is taken across scales, the harrowing effects of climate change are expected to increasingly threaten extensive populations globally. This dissertation provides insights into how households think, perceive, behave, and learn over time concerning one of the most deadly and damaging hazards: floods.